(report: T): ProbeReport {
return requestId === undefined ? report : { ...report, requestId }
}
function publishReport(report: ProbeReport): void {
window.__PROBE_REPORT__ = report
publishNavigationReport(report)
}
function setError(message: string): void {
stats.textContent = `Error: ${message}`
publishReport(withRequestId({ status: 'error', message }))
}
function getBrowserLinesFromSpans(prepared: PreparedTextWithSegments, measuredFont: string, dir: string): ProbeLine[] {
const lines: ProbeLine[] = []
const units = getDiagnosticUnits(prepared)
const spans: HTMLSpanElement[] = []
let currentLine = ''
let currentStart: number | null = null
let currentEnd = 0
let lastTop: number | null = null
diagnosticDiv.textContent = ''
for (const unit of units) {
const span = document.createElement('span')
span.textContent = unit.text
diagnosticDiv.appendChild(span)
spans.push(span)
}
function pushLine(): void {
if (currentStart === null || currentLine.length === 0) return
const content = getLineContent(currentLine, currentEnd)
lines.push({
text: currentLine,
renderedText: currentLine,
contentText: content.text,
start: currentStart,
end: currentEnd,
contentEnd: content.end,
fullWidth: measureCanvasTextWidth(diagnosticCtx, content.text, measuredFont),
domWidth: measureDomTextWidth(document, content.text, measuredFont, dir),
})
}
for (let i = 0; i < units.length; i++) {
const unit = units[i]!
const span = spans[i]!
const rect = span.getBoundingClientRect()
const top: number | null = rect.width > 0 || rect.height > 0 ? rect.top : lastTop
if (top !== null && lastTop !== null && top > lastTop + 0.5) {
pushLine()
currentLine = unit.text
currentStart = unit.start
currentEnd = unit.end
} else {
if (currentStart === null) currentStart = unit.start
currentLine += unit.text
currentEnd = unit.end
}
if (top !== null) lastTop = top
}
pushLine()
diagnosticDiv.textContent = text
return lines
}
function getBrowserLines(
prepared: PreparedTextWithSegments,
measuredFont: string,
dir: string,
method: 'range' | 'span',
): ProbeLine[] {
return method === 'span'
? getBrowserLinesFromSpans(prepared, measuredFont, dir)
: getBrowserLinesFromRange(prepared, measuredFont, dir)
}
function getBrowserLinesFromRange(prepared: PreparedTextWithSegments, measuredFont: string, dir: string): ProbeLine[] {
const textNode = diagnosticDiv.firstChild
const lines: ProbeLine[] = []
if (!(textNode instanceof Text)) return lines
const units = getDiagnosticUnits(prepared)
const range = document.createRange()
let currentLine = ''
let currentStart: number | null = null
let currentEnd = 0
let lastTop: number | null = null
function pushLine(): void {
if (currentStart === null || currentLine.length === 0) return
const content = getLineContent(currentLine, currentEnd)
lines.push({
text: currentLine,
renderedText: currentLine,
contentText: content.text,
start: currentStart,
end: currentEnd,
contentEnd: content.end,
fullWidth: measureCanvasTextWidth(diagnosticCtx, content.text, measuredFont),
domWidth: measureDomTextWidth(document, content.text, measuredFont, dir),
})
}
for (const unit of units) {
range.setStart(textNode, unit.start)
range.setEnd(textNode, unit.end)
const rects = range.getClientRects()
const top: number | null = rects.length > 0 ? rects[0]!.top : lastTop
if (top !== null && lastTop !== null && top > lastTop + 0.5) {
pushLine()
currentLine = unit.text
currentStart = unit.start
currentEnd = unit.end
} else {
if (currentStart === null) currentStart = unit.start
currentLine += unit.text
currentEnd = unit.end
}
if (top !== null) lastTop = top
}
pushLine()
return lines
}
function measurePreparedSlice(
prepared: PreparedTextWithSegments,
start: number,
end: number,
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "rg -n \"prepare|layoutWithLines|layoutNextLine|walkLineRanges|prepareWithSegments|walkPreparedLines|wrapGeometry|cursor|virtual|masonry|balance|justify\" pages/demos pages/*.ts",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "sed -n '1,240p' pages/demos/masonry/index.ts",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "sed -n '1,260p' pages/demos/wrap-geometry.ts",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "sed -n '1,260p' pages/demos/rich-note.ts",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc 'rg -n "prepare|layoutWithLines|layoutNextLine|walkLineRanges|prepareWithSegments|walkPreparedLines|wrapGeometry|cursor|virtual|masonry|balance|justify" pages/demos pages/*.ts'
Chunk ID: 595917
Wall time: 0.0001 seconds
Process exited with code 0
Original token count: 69674
Output:
Total output lines: 311
pages/diagnostic-utils.ts:11:export function getDiagnosticUnits(prepared: PreparedTextWithSegments): DiagnosticUnit[] {
pages/diagnostic-utils.ts:15: for (let i = 0; i < prepared.segments.length; i++) {
pages/diagnostic-utils.ts:16: const segment = prepared.segments[i]!
pages/diagnostic-utils.ts:17: if (prepared.breakableWidths[i] !== null) {
pages/gatsby.ts:3: layoutWithLines,
pages/gatsby.ts:4: prepareWithSegments,
pages/gatsby.ts:209:const prepared = prepareWithSegments(text, FONT)
pages/gatsby.ts:210:const segmentSpans = buildSegmentSpans(prepared)
pages/gatsby.ts:303:function buildSegmentSpans(preparedText: PreparedTextWithSegments): SegmentSpan[] {
pages/gatsby.ts:307: for (let i = 0; i < preparedText.segments.length; i++) {
pages/gatsby.ts:308: const segText = preparedText.segments[i]!
pages/gatsby.ts:316: width: preparedText.widths[i]!,
pages/gatsby.ts:317: isSpace: preparedText.kinds[i] === 'space',
pages/gatsby.ts:318: breakable: preparedText.breakableWidths[i] !== null,
pages/gatsby.ts:424: preparedText: PreparedTextWithSegments,
pages/gatsby.ts:431: const units = getDiagnosticUnits(preparedText)
pages/gatsby.ts:485: preparedText: PreparedTextWithSegments,
pages/gatsby.ts:488: const layoutLines = layoutWithLines(preparedText, maxWidth, LINE_HEIGHT).lines
pages/gatsby.ts:615: const ourLines = getOurLines(prepared, contentWidth)
pages/gatsby.ts:616: const browserLines = getBrowserLines(prepared, diagnosticDiv)
pages/gatsby.ts:659: const predicted = layout(prepared, contentWidth, LINE_HEIGHT)
pages/benchmark.ts:2: prepare,
pages/benchmark.ts:3: prepareWithSegments,
pages/benchmark.ts:5: layoutNextLine,
pages/benchmark.ts:6: layoutWithLines,
pages/benchmark.ts:7: walkLineRanges,
pages/benchmark.ts:67: prepareMs: number
pages/benchmark.ts:263: const prepareSamples: number[] = []
pages/benchmark.ts:271: prepareSamples.push(profile.totalMs)
pages/benchmark.ts:277: const prepareMs = median(prepareSamples)
pages/benchmark.ts:282: const prepared = prepareWithSegments(corpus.text, corpus.font)
pages/benchmark.ts:283: const lineCount = layout(prepared, corpus.width, corpus.lineHeight).lineCount
pages/benchmark.ts:287: const result = layout(prepared, width, corpus.lineHeight)
pages/benchmark.ts:297: segments: prepared.widths.length,
pages/benchmark.ts:298: breakableSegments: prepared.breakableWidths.filter(widths => widths !== null).length,
pages/benchmark.ts:303: prepareMs,
pages/benchmark.ts:313: prepared: PreparedTextWithSegments[],
pages/benchmark.ts:321: const layoutWithLinesMs = bench(repeatIndex => {
pages/benchmark.ts:324: for (let i = 0; i < prepared.length; i++) {
pages/benchmark.ts:325: const result = layoutWithLines(prepared[i]!, width, lineHeight)
pages/benchmark.ts:331: const walkLineRangesMs = bench(repeatIndex => {
pages/benchmark.ts:334: for (let i = 0; i < prepared.length; i++) {
pages/benchmark.ts:335: sum += walkLineRanges(prepared[i]!, width, line => {
pages/benchmark.ts:342: const layoutNextLineMs = bench(repeatIndex => {
pages/benchmark.ts:345: for (let i = 0; i < prepared.length; i++) {
pages/benchmark.ts:346: let cursor = { segmentIndex: 0, graphemeIndex: 0 }
pages/benchmark.ts:348: const line = layoutNextLine(prepared[i]!, cursor, width)
pages/benchmark.ts:351: cursor = line.end
pages/benchmark.ts:361: label: 'Our library: layoutWithLines()',
pages/benchmark.ts:362: ms: layoutWithLinesMs,
pages/benchmark.ts:366: label: 'Our library: walkLineRanges()',
pages/benchmark.ts:367: ms: walkLineRangesMs,
pages/benchmark.ts:371: label: 'Our library: layoutNextLine()',
pages/benchmark.ts:372: ms: layoutNextLineMs,
pages/benchmark.ts:431: // Pre-prepare for layout benchmark
pages/benchmark.ts:432: const prepared: PreparedText[] = []
pages/benchmark.ts:434: prepared.push(prepare(texts[i]!, FONT))
pages/benchmark.ts:441: // --- 1. prepare() ---
pages/benchmark.ts:442: root.innerHTML = 'Benchmarking prepare()...
'
pages/benchmark.ts:447: prepare(texts[i]!, FONT)
pages/benchmark.ts:450: results.push({ label: 'Our library: prepare()', ms: tPrepare, desc: `One cold ${COUNT}-text measurement batch` })
pages/benchmark.ts:459: const result = layout(prepared[i]!, maxWidth, LINE_HEIGHT)
pages/benchmark.ts:504: const richPrepared = richTexts.map(text => prepareWithSegments(text, FONT))
pages/benchmark.ts:518: prepareWithSegments(
pages/benchmark.ts:537: // Relative speed only for resize approaches (layout vs DOM). prepare() is
pages/benchmark.ts:556: ${RICH_COUNT} shared-corpus texts prepared with segments. Median ms per batch across widths ${RICH_LAYOUT_SAMPLE_WIDTHS.join('/')}px. This tracks the richer APIs used by shrinkwrap, custom layout, and manual reflow.
pages/benchmark.ts:561: ${RICH_LONG_REPEAT} copies of the Arabic long-form corpus prepared with segments. Median ms per batch across widths ${RICH_LONG_SAMPLE_WIDTHS.join('/')}px. This is the richer-path worst-case canary.
pages/benchmark.ts:586: // prepare (cold)
pages/benchmark.ts:589: clearCache(); let t0 = performance.now(); prepare(cjk, FONT); pTimes.cjk.push(performance.now() - t0)
pages/benchmark.ts:590: clearCache(); t0 = performance.now(); prepare(lat, FONT); pTimes.lat.push(performance.now() - t0)
pages/benchmark.ts:595: const pc = prepareWithSegments(cjk, FONT)
pages/benchmark.ts:596: const pl = prepareWithSegments(lat, FONT)
pages/benchmark.ts:629: | Chars | CJK segs | Latin segs | CJK prepare (ms) | Latin prepare (ms) | CJK layout/1k (ms) | Latin layout/1k (ms) |
|---|
pages/benchmark.ts:644: ${result.prepareMs.toFixed(2)} |
pages/benchmark.ts:650: Long-form rows split cold prepare into text analysis and measurement phases for one full corpus text, then report one hot layout pass over the prepared result. They are intended to catch script-specific prepare regressions that the short shared corpus can hide.
pages/probe.ts:3: layoutWithLines,
pages/probe.ts:4: prepareWithSegments,
pages/probe.ts:138:function getBrowserLinesFromSpans(prepared: PreparedTextWithSegments, measuredFont: string, dir: string): ProbeLine[] {
pages/probe.ts:140: const units = getDiagnosticUnits(prepared)
pages/probe.ts:196: prepared: PreparedTextWithSegments,
pages/probe.ts:202: ? getBrowserLinesFromSpans(prepared, measuredFont, dir)
pages/probe.ts:203: : getBrowserLinesFromRange(prepared, measuredFont, dir)
pages/probe.ts:206:function getBrowserLinesFromRange(prepared: PreparedTextWithSegments, measuredFont: string, dir: string): ProbeLine[] {
pages/probe.ts:211: const units = getDiagnosticUnits(prepared)
pages/probe.ts:258: prepared: PreparedTextWithSegments,
pages/probe.ts:266: for (let i = 0; i < prepared.segments.length; i++) {
pages/probe.ts:267: const segment = prepared.segments[i]!
pages/probe.ts:285: total += prepared.widths[i]!
pages/probe.ts:297: prepared: PreparedTextWithSegments,
pages/probe.ts:303: return layoutWithLines(prepared, contentWidth, lineHeight).lines.map(line => {
pages/probe.ts:306: : computeOffsetFromCursor(prepared, line.start)
pages/probe.ts:307: const end = computeOffsetFromCursor(prepared, line.end)
pages/probe.ts:321: sumWidth: measurePreparedSlice(prepared, start, contentEnd, measuredFont),
pages/probe.ts:336:function computeOffsetFromCursor(prepared: PreparedTextWithSegments, cursor: { segmentIndex: number, graphemeIndex: number }): number {
pages/probe.ts:338: for (let i = 0; i < cursor.segmentIndex; i++) offset += prepared.segments[i]!.length
pages/probe.ts:339: if (cursor.graphemeIndex === 0 || cursor.segmentIndex >= prepared.segments.length) return offset
pages/probe.ts:342: for (const grapheme of graphemeSegmenter.segment(prepared.segments[cursor.segmentIndex]!)) {
pages/probe.ts:343: if (graphemeIndex >= cursor.graphemeIndex) break
pages/probe.ts:439: const prepared = prepareWithSegments(text, font, { whiteSpace })
pages/probe.ts:440: const normalizedText = prepared.segments.join('')
pages/probe.ts:442: const predicted = layout(prepared, contentWidth, lineHeight)
pages/probe.ts:444: const ourLines = getPublicLines(prepared, normalizedText, contentWidth, lineHeight, font)
pages/probe.ts:446: const browserLines = getBrowserLines(prepared, font, direction, browserLineMethod)
pages/probe.ts:447: const alternateBrowserLines = getBrowserLines(prepared, font, direction, alternateBrowserLineMethod)
pages/accuracy.ts:4: layoutWithLines,
pages/accuracy.ts:5: prepareWithSegments,
pages/accuracy.ts:160: prepared: PreparedTextWithSegments,
pages/accuracy.ts:166: const units = getDiagnosticUnits(prepared)
pages/accuracy.ts:209: const prepared: PreparedTextWithSegments[] = []
pages/accuracy.ts:221: prepared.push(prepareWithSegments(text, font))
pages/accuracy.ts:227: const predicted = layout(prepared[i]!, maxWidth, lineHeight).height
pages/accuracy.ts:240: const browserLines = getBrowserLines(prepared[i]!, divs[i]!)
pages/accuracy.ts:241: const ourLayout = layoutWithLines(prepared[i]!, maxWidth, lineHeight)
pages/corpus.ts:3: layoutWithLines,
pages/corpus.ts:4: prepareWithSegments,
pages/corpus.ts:200: layoutWithLines: (width: number) => ReturnType
pages/corpus.ts:361: prepared: PreparedTextWithSegments,
pages/corpus.ts:366: const units = getDiagnosticUnits(prepared)
pages/corpus.ts:409: prepared: PreparedTextWithSegments,
pages/corpus.ts:420: const units = getDiagnosticUnits(prepared)
pages/corpus.ts:451:function getCursorOffset(prepared: PreparedTextWithSegments, segmentIndex: number, graphemeIndex: number): number {
pages/corpus.ts:454: offset += prepared.segments[i]!.length
pages/corpus.ts:456: if (graphemeIndex === 0 || segmentIndex >= prepared.segments.length) {
pages/corpus.ts:462: for (const grapheme of diagnosticGraphemeSegmenter.segment(prepared.segments[segmentIndex]!)) {
pages/corpus.ts:471: prepared: PreparedTextWithSegments,
pages/corpus.ts:477: return layoutWithLines(prepared, maxWidth, lineHeight).lines.map(line => {
pages/corpus.ts:478: const start = getCursorOffset(prepared, line.start.segmentIndex, line.start.graphemeIndex)
pages/corpus.ts:479: const end = getCursorOffset(prepared, line.end.segmentIndex, line.end.graphemeIndex)
pages/corpus.ts:498: prepared: PreparedTextWithSegments,
pages/corpus.ts:506: for (let i = 0; i < prepared.segments.length; i++) {
pages/corpus.ts:507: const text = prepared.segments[i]!
pages/corpus.ts:512: width: prepared.widths[i]!,
pages/corpus.ts:514: isSpace: prepared.kinds[i] === 'space',
pages/corpus.ts:567: prepared: PreparedTextWithSegments,
pages/corpus.ts:604: oursSegments: ours ? getLineSegments(prepared, ours.start, ours.end, font, direction) : [],
pages/corpus.ts:709: prepared: PreparedTextWithSegments,
pages/corpus.ts:720: const ourLines = getOurLines(prepared, normalizedText, contentWidth, lineHeight, font)
pages/corpus.ts:721: const probeResult = getBrowserLinesFromSpans(prepared, lineProbeDiv, normalizedText, font)
pages/corpus.ts:722: const rangeResult = getBrowserLinesFromRange(prepared, diagnosticDiv, normalizedText, font)
pages/corpus.ts:774: const segments = getLineSegments(prepared, ours.start, ours.end, font, direction)
pages/corpus.ts:790: prepared,
pages/corpus.ts:799: prepared,
pages/corpus.ts:855: const prepared = currentPrepared
pages/corpus.ts:856: const normalizedText = prepared.segments.join('')
pages/corpus.ts:862: const predicted = layout(prepared, contentWidth, lineHeight)
pages/corpus.ts:882: report = addDiagnostics(report, prepared, font, lineHeight, contentWidth, normalizedText, direction)
pages/corpus.ts:893: layoutWithLines: nextWidth => layoutWithLines(prepared, nextWidth - PADDING * 2, lineHeight),
pages/corpus.ts:1060: const fullPrepared = prepareWithSegments(rawText, font)
pages/corpus.ts:1071: : prepareWithSegments(currentText, font)
pages/demos/bubbles.html:252: Uses walkLineRanges() to binary-search the tightest width
pages/demos/bubbles.html:279: walkLineRanges() does, without DOM text measurement in the
pages/demos/dynamic-layout.html:32: cursor: default;
pages/demos/dynamic-layout.html:115: cursor: text;
pages/demos/dynamic-layout.html:127: cursor: text;
pages/demos/dynamic-layout.html:155: cursor: text;
pages/demos/variable-typographic-ascii.ts:1:import { prepareWithSegments } from '../../src/layout.ts'
pages/demos/variable-typographic-ascii.ts:90: const prepared = prepareWithSegments(ch, font)
pages/demos/variable-typographic-ascii.ts:91: return prepared.widths.length > 0 ? prepared.widths[0]! : 0
pages/demos/rich-note.html:86: justify-content: center;
pages/demos/rich-note.html:150: justify-content: center;
pages/demos/rich-note.html:161: justify-items: stretch;
pages/demos/masonry/index.ts:1:import { prepare, layout, type PreparedText } from '../../../src/layout.ts'
pages/demos/masonry/index.ts:14: prepared: PreparedText
pages/demos/masonry/index.ts:34:// --- prepare all texts upfront ---
pages/demos/masonry/index.ts:38: prepared: prepare(text, font),
pages/demos/masonry/index.ts:80: const { height } = layout(st.cards[i]!.prepared, textWidth, lineHeight)
pages/demos/justification-comparison.model.ts:2: prepareWithSegments,
pages/demos/justification-comparison.model.ts:3: layoutNextLine,
pages/demos/justification-comparison.model.ts:116: basePreparedParagraphs: PARAGRAPHS.map(paragraph => prepareWithSegments(paragraph, FONT)),
pages/demos/justification-comparison.model.ts:117: hyphenatedPreparedParagraphs: PARAGRAPHS.map(paragraph => prepareWithSegments(hyphenateParagraphText(paragraph), FONT)),
pages/demos/justification-comparison.model.ts:205: preparedParagraphs: PreparedTextWithSegments[],
pages/demos/justification-comparison.model.ts:210: for (let index = 0; index < preparedParagraphs.length; index++) {
pages/demos/justification-comparison.model.ts:211: paragraphs.push(layoutParagraphGreedy(preparedParagraphs[index]!, maxWidth, hyphenWidth))
pages/demos/justification-comparison.model.ts:217: prepared: PreparedTextWithSegments,
pages/demos/justification-comparison.model.ts:222: let cursor: LayoutCursor = { segmentIndex: 0, graphemeIndex: 0 }
pages/demos/justification-comparison.model.ts:225: const line = layoutNextLine(prepared, cursor, maxWidth)
pages/demos/justification-comparison.model.ts:227: lines.push(buildMeasuredLineFromLayoutResult(prepared, line.start, line.end, maxWidth, hyphenWidth))
pages/demos/justification-comparison.model.ts:228: cursor = line.end
pages/demos/justification-comparison.model.ts:235: prepared: PreparedTextWithSegments,
pages/demos/justification-comparison.model.ts:241: const ending: LineEnding = end.segmentIndex >= prepared.segments.length ? 'paragraph-end' : 'wrap'
pages/demos/justification-comparison.model.ts:246: const text = prepared.segments[segIndex]!
pages/demos/justification-comparison.model.ts:251: segments.push(toLineSegment(text, prepared.widths[segIndex]!))
pages/demos/justification-comparison.model.ts:254: if (trailingMarker === 'none' && end.segmentIndex < prepared.segments.length) {
pages/demos/justification-comparison.model.ts:255: if (prepared.segments[end.segmentIndex] === SOFT_HYPHEN) trailingMarker = 'soft-hyphen'
pages/demos/justification-comparison.model.ts:267: preparedParagraphs: PreparedTextWithSegments[],
pages/demos/justification-comparison.model.ts:272: for (let index = 0; index < preparedParagraphs.length; index++) {
pages/demos/justification-comparison.model.ts:273: paragraphs.push(layoutParagraphOptimal(preparedParagraphs[index]!, maxWidth, resources))
pages/demos/justification-comparison.model.ts:279: prepared: PreparedTextWithSegments,
pages/demos/justification-comparison.model.ts:283: const segments = prepared.segments
pages/demos/justification-comparison.model.ts:284: const widths = prepared.widths
pages/demos/justification-comparison.model.ts:348: lines.push(buildMeasuredLineFromCandidateRange(prepared, breakCandidates, fromCandidate, toCandidate, maxWidth, resources.hyphenWidth))
pages/demos/justification-comparison.model.ts:438: prepared: PreparedTextWithSegments,
pages/demos/justification-comparison.model.ts:454: const text = prepared.segments[segIndex]!
pages/demos/justification-comparison.model.ts:456: segments.push(toLineSegment(text, prepared.widths[segIndex]!))
pages/demos/dynamic-layout.ts:8:- The left column consumes text first, and the right column resumes from the same cursor.
pages/demos/dynamic-layout.ts:24:import { layoutNextLine, prepareWithSegments, walkLineRanges, type LayoutCursor, type PreparedTextWithSegments } from '../../src/layout.ts'
pages/demos/dynamic-layout.ts:154:const preparedByKey = new Map()
pages/demos/dynamic-layout.ts:219:const preparedBody = getPrepared(BODY_COPY, BODY_FONT)
pages/demos/dynamic-layout.ts:220:const preparedCredit = getPrepared(CREDIT_TEXT, CREDIT_FONT)
pages/demos/dynamic-layout.ts:221:const creditWidth = Math.ceil(getPreparedSingleLineWidth(preparedCredit))
pages/demos/dynamic-layout.ts:229: const cached = preparedByKey.get(key)
pages/demos/dynamic-layout.ts:231: const prepared = prepareWithSegments(text, font)
pages/demos/dynamic-layout.ts:232: preparedByKey.set(key, prepared)
pages/demos/dynamic-layout.ts:233: return prepared
pages/demos/dynamic-layout.ts:236:function getPreparedSingleLineWidth(prepared: PreparedTextWithSegments): number {
pages/demos/dynamic-layout.ts:238: walkLineRanges(prepared, 100_000, line => {
pages/demos/dynamic-layout.ts:244:function headlineBreaksInsideWord(prepared: PreparedTextWithSegments, maxWidth: number): boolean {
pages/demos/dynamic-layout.ts:246: walkLineRanges(prepared, maxWidth, line => {
pages/demos/dynamic-layout.ts:276: prepared: PreparedTextWithSegments,
pages/demos/dynamic-layout.ts:282:): { lines: PositionedLine[], cursor: LayoutCursor } {
pages/demos/dynamic-layout.ts:283: let cursor: LayoutCursor = startCursor
pages/demos/dynamic-layout.ts:326: const line = layoutNextLine(prepared, cursor, width)
pages/demos/dynamic-layout.ts:336: cursor = line.end
pages/demos/dynamic-layout.ts:340: return { lines, cursor }
pages/demos/dynamic-layout.ts:671: preparedBody: PreparedTextWithSegments,
pages/demos/dynamic-layout.ts:764: preparedBody,
pages/demos/dynamic-layout.ts:784: preparedBody,
pages/demos/dynamic-layout.ts:793: preparedBody,
pages/demos/dynamic-layout.ts:794: leftResult.cursor,
pages/demos/dynamic-layout.ts:819: const { headlineLines, creditLeft, creditTop, leftLines, rightLines, contentHeight, hits } = evaluateLayout(layout, lineHeight, preparedBody)
pages/demos/dynamic-layout.ts:847: document.body.style.cursor = hoveredLogo === null ? '' : 'pointer'
pages/demos/index.html:135:
pages/demos/bubbles.ts:5: prepareBubbleTexts,
pages/demos/bubbles.ts:25:const preparedBubbles = prepareBubbleTexts(shrinkNodes.map(readNodeText))
pages/demos/bubbles.ts:107: const renderState = computeBubbleRender(preparedBubbles, chatWidth)
pages/demos/accordion.html:81: cursor: pointer;
pages/demos/accordion.html:98: justify-self: end;
pages/demos/bubbles-shared.ts:1:import { layout, prepareWithSegments, walkLineRanges, type PreparedTextWithSegments } from '../../src/layout.ts'
pages/demos/bubbles-shared.ts:10: prepared: PreparedTextWithSegments
pages/demos/bubbles-shared.ts:36:export function prepareBubbleTexts(texts: string[]): PreparedBubble[] {
pages/demos/bubbles-shared.ts:38: prepared: prepareWithSegments(text, FONT),
pages/demos/bubbles-shared.ts:49:export function collectWrapMetrics(prepared: PreparedTextWithSegments, maxWidth: number): WrapMetrics {
pages/demos/bubbles-shared.ts:51: const lineCount = walkLineRanges(prepared, maxWidth, line => {
pages/demos/bubbles-shared.ts:61:export function findTightWrapMetrics(prepared: PreparedTextWithSegments, maxWidth: number): WrapMetrics {
pages/demos/bubbles-shared.ts:62: const initial = collectWrapMetrics(prepared, maxWidth)
pages/demos/bubbles-shared.ts:68: const midLineCount = layout(prepared, mid, LINE_HEIGHT).lineCount
pages/demos/bubbles-shared.ts:76: return collectWrapMetrics(prepared, lo)
pages/demos/bubbles-shared.ts:79:export function computeBubbleRender(preparedBubbles: PreparedBubble[], chatWidth: number): BubbleRenderState {
pages/demos/bubbles-shared.ts:85: for (let index = 0; index < preparedBubbles.length; index++) {
pages/demos/bubbles-shared.ts:86: const bubble = preparedBubbles[index]!
pages/demos/bubbles-shared.ts:87: const cssMetrics = collectWrapMetrics(bubble.prepared, contentMaxWidth)
pages/demos/bubbles-shared.ts:88: const tightMetrics = findTightWrapMetrics(bubble.prepared, contentMaxWidth)
pages/demos/editorial-engine.ts:2: layoutNextLine,
pages/demos/editorial-engine.ts:3: layoutWithLines,
pages/demos/editorial-engine.ts:4: prepareWithSegments,
pages/demos/editorial-engine.ts:5: walkLineRanges,
pages/demos/editorial-engine.ts:105: prepared: PreparedTextWithSegments
pages/demos/editorial-engine.ts:190:A messaging application needs to know the exact height of every message bubble before rendering a virtualized list. A masonry layout needs the height of every card to position them without overlap. An editorial page needs text to flow around images, advertisements, and interactive elements. A responsive dashboard needs to resize and reflow text in real time as the user drags a panel divider.
pages/demos/editorial-engine.ts:216:Virtualized text rendering becomes exact rather than estimated. A virtual list needs to know the height of items before they enter the viewport, so it can position them correctly and calculate scroll extent. Without pretext, you must either render items off-screen to measure them (defeating the purpose of virtualization) or estimate heights and accept visual jumping when items enter the viewport with different heights than predicted. Pretext computes exact heights without creating any DOM elements, enabling perfect virtualization with zero visual artifacts.
pages/demos/editorial-engine.ts:218:Multi-column text flow with cursor handoff is perhaps the most striking capability. The left column consumes text until it reaches the bottom, then hands its cursor to the right column. The right column picks up exactly where the left column stopped, with no duplication, no gap, and perfect line breaking at the column boundary. This is how newspapers and magazines work on paper, but it has never been achievable on the web without extreme hacks involving multiple elements, hidden overflow, and JavaScript-managed content splitting.
pages/demos/editorial-engine.ts:220:Pretext makes it trivial. Call layoutNextLine in a loop for the first column, using the column width. When the column is full, take the returned cursor and start a new loop for the second column. The cursor carries the exact position in the prepared text — which segment, which grapheme within that segment. The second column continues seamlessly from the first.
pages/demos/editorial-engine.ts:275:const preparedBody = prepareWithSegments(BODY_TEXT, BODY_FONT)
pages/demos/editorial-engine.ts:278:const preparedPullquotes = PULLQUOTE_TEXTS.map(text => prepareWithSegments(text, PQ_FONT))
pages/demos/editorial-engine.ts:280: { prepared: preparedPullquotes[0]!, placement: { colIdx: 0, yFrac: 0.48, wFrac: 0.52, side: 'right' } },
pages/demos/editorial-engine.ts:281: { prepared: preparedPullquotes[1]!, placement: { colIdx: 1, yFrac: 0.32, wFrac: 0.5, side: 'left' } },
pages/demos/editorial-engine.ts:286:const preparedDropCap = prepareWithSegments(DROP_…57674 tokens truncated…LI5: How did we get to the point where laptops and smartphones are in the same price range?","ELI5: Stock Market Megathread","ELI5: So how does the the human brain ignore the second the?","ELI5: Why can people walk many miles without discomfort, but when they stand for more than 15 minutes or so, they get uncomfortable?","ELI5: There are infinite numbers between 0 and 1. There are also infinite numbers between 0 and 2. There would more numbers between 0 and 2. How can a set of infinite numbers be bigger than another infinite set?","ELI5 Why is 12 hour time even taught? Wouldn’t it just be easier to remember 13:00 instead of 1:00pm?","ELI5: Military officers swear to protect and defend the Constitution of the United States, not the President","ELI5 remembers u/bossgalaga","ELI5 why do humans need to eat many different kind of foods to get their vitamins etc but large animals like cows only need grass to survive?","ELI5 If diamonds and other gemstones can be lab created, and indistinguishable from their naturally mined counterparts, why are we still paying so much for these jewelry stones?","ELI5: How come you can be falling asleep watching TV, then wide awake when you go to bed five minutes later?","ELI5: How did Germany stop being Nazis after the end of WWII? Did everyone just \"snap out of it\" after Hitler's death?","ELI5: The Panama Papers","ELI5: Addressing Concerns Regarding Reddit","ELI5:Do donated organs age according to the donor´s age or do they adapt to the age of the new body?","ELI5: If there is no cellphone signal, how does the \"emergency calls only\" mode works?","ELI5: Why is it, that you can eat a 2,000 calorie meal, and in theory, you shouldn't need calories again until the next day, but you can be hungry again 6-8 hours after you finish eating? Is your body just not capable of actually processing that many calories?","ELI5: what is the reason that almost every video game today has removed the ability for split screen, including ones that got famous and popular from having split screen?","ELI5: How does your body burn 2000 calories a day, but you have to run a mile to burn 100 extra?","ELI5: Went on vacation. Fridge died while I was gone. Came back to a freezer full of maggots. How do maggots get into a place like a freezer that's sealed air tight?","Eli5: If ants love sugar, and bees make honey, why aren’t bee hives constantly attacked by ants?","ELI5: Why do traditional cars lack any decent ability to warn the driver that the battery is low or about to die?","ELI5: Why aren't power lines in the US burried underground so that everyone doesn't lose power during hurricanes and other natural disasters?","ELI5: How can large chains (Target, Walmart, etc) produce store brand versions of nearly every product imaginable while industry manufacturers only really produce a single type of item?","ELI5: Why does \"Hoo\" produce cold air but \"Haa\" produces hot air ?","ELI5: Why is it that Mandarin and Cantonese are considered dialects of Chinese but Spanish, Portuguese, Italian, and French are considered separate languages and not dialects of Latin?","ELI5: If bacteria die from (for example, boiled water) where do their corpses go?","ELI5: if fruit is sweet to encourage animals to eat it and carry the seeds away from the parent tree, how do lemons and limes fit into this mix?","ELI5: Why does making a 3 degree difference in your homes thermostat feel like a huge change in temperature, but outdoors it feels like nothing?","ELI5: Why do you need a Master's Degree to become a librarian, especially when the median salary is barely above $50,000?","ELI5: Why do blockbuster movies like Avatar and End Game have there success measured in terms of money made instead of tickets sold, wouldn’t that make it easier to compare to older movies without accounting for today’s dollar vs a dollar 30 years ago?","ELI5: How come all those atomic bomb tests were conducted during 60s in deserts in Nevada without any serious consequences to environment and humans?","ELI5: NASA Engineers just communicated with Voyager 1 which is 21 BILLION kilometers away (and out of our solar system) and it communicated back. How is this possible?","ELI5: Why do \"bad smells\" like smoke and rotting food linger longer and are harder to neutralize than \"good smells\" like flowers or perfume?","ELI5: What did Edward Snowden actually reveal abot the U.S Government?","ELI5: Why after a good long cry can't we take a big deep breath without that huh-huh-huh tracheal contraction?","ELI5: How can nothing be faster than light when speed is only relative?","ELI5: Why is W called \"double U\" when it is clearly \"double V\"?","ELI5: How, at 93 million miles away, does the sun feel so warm, yet when a simple cloud passes over it the warmth is incredibly dampened?","ELI5: When toddlers talk ‘gibberish’ are they just making random noises or are they attempting to speak an English sentence that just comes out muddled up?","ELI5: Why do some animals (like spiders or lizards) spend so much time just doing nothing? What is happening and why?","ELI5: Why is it that you can keep a house phone on it's charging dock for years and it doesn't destroy the battery where as a cellphone will eventually wither over just a couple years if you charge it for too long everyday?","ELI5: Why do some letters have a completely different character when written in uppercase (A/a, R/r, E/e, etc), whereas others simply have a larger version of themselves (S/s, P/p, W/w, etc)?","ELI5: Why does hearing yourself speak with a few seconds of delay, completely crash your brain?","ELI5: Why were ridiculously fast planes like the SR-71 built, and why hasn't it speed record been broken for 50 years?","Eli5: Caffeine has almost no calories, but seems to give us a burst of energy on its own. Where does the body get this energy from? Is caffeine forcing the body to use stored fat?","ELI5: Why does your body feel physically ill after experiencing emotional trauma?","ELI5 What is it about grapefruit specifically that messes with pretty much every prescription in existence?","ELI5: What does it mean when scientists say “an eagle can see a rabbit in a field from a mile away”. Is their vision automatically more zoomed in? Do they have better than 20/20 vision? Is their vision just clearer?","ELI5: If I enter a password wrong thrice, the system locks me out. How are hackers able to attempt millions of combinations of passwords without the system locking them out?","ELI5: If the amazon echo doesn’t start processing audio until you say “Alexa”, how does it know when you say it?","ELI5: Why do alcoholics die when they stop drinking?","ELI5: Why is it healthy to strain your heart through exercise, but unhealthy to strain it through stress, caffeine, nicotine etc? What is the difference between these kinds of cardiac strain?","ELi5: When a baby is born, how are their lungs instantly able to breathe air if they haven't been breathing air for 9 months?","ELI5: Why is it children’s shampoo is “tear free” while regular shampoo burns like all hell in the eyes?","ELI5: Why is finding \"patient zero\" in an epidemic so important?","ELI5: You're not supposed to defrost meats in warm water due to harmful bacteria growth, you're not supposed to leave food at room temperature for long without being refrigerated because of harmful growth but, when you go to a buffet, food can sit out for hours under heat lamps and be fine?","ELI5: how can our brains remember that we forgot something, but it can't remember what we forgot?","ELI5: Why is it that when we watch footage from the 70s a lot of times it looks better than footage of the 90s?","ELI5 the difference between 4 Wheel Drive and All Wheel Drive.","ELI5: Why do older emulated games still occasionally slow down when rendering too many sprites, even though it's running on hardware thousands of times faster than what it was programmed on originally?","ELI5: Why do ships have circular windows instead of square ones?","ELI5: How do ships anchor themselves in very deep waters? For example, if they anchored in 10K foot deep oceans, do they actually have 10K feet of anchor chains?","ELI5: what is a hedge-fund?","ELI5: Why can't bots check 'I am not a robot' checkboxes?","eli5 Why does down syndrome cause an almost identical face structure no matter the parents genes?","ELI5: Why does a candle not create smoke when burning but lots of smoke when you blow it out?","ELI5: why can't we have supplements or pills for dopamine, oxytocin, serotonin or endorphins just like we have melatonin or contraceptive pills?","ELI5 : how are we sure that we all see the same colors ?","ELI5: Why is it that it takes few seconds for our body to decide that it's had enough water not to be thirsty, but several minutes to recognize that no more food is needed cuz it's not hungry?","ELI5 Why do people seem to age so incredibly fast after a traumatic experience?","ELI5: What actually happens when we unintentionally start to drift off to sleep but our body suddenly \"shocks\" us awake?","ELI5: When you restart a PC, does it completely \"shut down\"? If it does, what tells it to power up again? If it doesn't, why does it behave like it has been shut down?","ELI5: Whem pouring liquid from one container to another (bowl, cup), why is it that sometimes it pours gloriously without any spills but sometimes the liquid decides to fucking run down the side of the container im pouring from and make a mess all around the surface?","ELI5: Queen Victoria ruled over one of the most powerful empires in history for almost a century. So why did it take until 1918 for women to be considered politically intelligent and allowed to vote?","ELI5: How can the same side of the moon always face earth? Doesn't it rotate?","ELI5: How is peach flavoring so easily captured in gummies, water, etc, when so many other flavors taste obviously fake?","ELI5: What is 'gaslighting' and some examples?","ELI5: Why do most hard candies just shrink down as you suck on them but peppermints get all porous and full of holes?","ELI5: Suicide is listed as a side effect of over 200 common medications. How, specifically, do these medications increase the risk of suicide?","ELI5: Why are so many electrical plugs designed in such a way that they cover adjacent sockets?","ELI5: If the internet is primarily dependent on cables that run through oceans connecting different countries and continents. During a war, anyone can cut off a country's access to the internet. Are there any backup or mitigant in place to avoid this? What happens if you cut the cable?","ELI5: How did the U.S. rise to a global superpower in only 250 years but counties that have been around for 1000s of years are still under-developed?","ELI5: Why does it seem so challenging now to send a manned crew to the moon, when we were able to accomplish this over 50 years ago?","ELI5: What makes a beer belly how it is, round and hard? What makes it different from a normal stomach or a soft(fat) stomach?","ELI5: What is the \"sharp\" in sharp cheddar? How are there various levels of \"sharp\"?","ELI5: Do birds fly for days while over the ocean? How do they sleep?","ELI5: Why is armpit sweat much more pungent than sweat from other areas of the body, such as back sweat?","ELI5:Why do our brains choose short term convenience and long term inconvenience over short term inconvenience and long term convenience? Example included.","ELI5: Why are password managers considered good security practice when they provide a single entry for an attacker to get all of your credentials?","ELI5 : Why does travelling make you feel so tired when you've just sat there for hours doing nothing?","eli5: How comes when you buy vitamins separately, they all come in these large capsules/tablets, but when you buy multivitamins, they can squeeze every vitamin in a tiny tablet?","ELI5: How do recycling factories deal with the problem of people putting things in the wrong bins?","ELI5: If the whole purpose of a fruit/vegetable is to spread seeds by being eaten and what out, why are chilly peppers doing there best to prevent this?","ELI5: Why are modern artists able to draw hyper-realistic art using just a pen/pencil, but artists from 100+ years ago weren’t able to?","ELI5: I’m told skin-to-skin contact leads to healthier babies, stronger romantic relationshipd, etc. but how does our skin know it’s touching someone else’s skin (as opposed to, say, leather)?","ELI5: How does a brain anus rhythm instantly kill you","ELI5 why are there stenographers in courtrooms, can't we just record what is being said?","ELI5: What happens to insects that accidentally travel long distances in cars?","ELI5 Why doesnt Chatgpt and other LLM just say they don't know the answer to a question?","ELI5: Why are poor people warned to avoid loans whereas rich people seem to operate constantly through them?","ELI5: Why is black worn in hot climates to keep cool?","ELi5: why do girls go into puberty so young when pregnancy for them would be unsafe and lead to poor outcomes?","ELI5 why you’re not supposed to sit on the toilet for a long time","ELI5: Why is \"C\" the default Hard Drive letter & not \"A\"","ELI5: The last B-2 bomber was manufactured in 2000. How is it that no other country managed to produce something comparable?","ELI5: When ChatGPT came out, why did so many companies suddenly release their own large language AIs?","ELI5 How does instagram/ social media know what exactly i am discussing with friends if it doesn't record my audio, looking for keywords all the time?","ELI5 Why do waiters leave with your payment card?","ELI5 If you were on a spaceship going 99.9999999999% the speed of light and you started walking, why wouldn’t you be moving faster than the speed of light?","ELI5: How can Paramount announce a hostile takeover bid for WB when the bidding was done and Netflix won?","ELI5: Why is squatting (in someone's house) a thing? And how come it becomes a problem for the owner? Can't they claim trespassing to the cops instead of saying the person is squatting?","ELI5: How did the explorers from hundreds of years ago provide drinking water to their crew for months on end?","ELI5: why don’t planes board back to front, surely that would be faster?","ELI5: When we get sick and get congested, where does the seemingly never ending flow of mucus/snot come from?","ELI5: Why do broken jaws not happen all the time in professional boxing?","ELI5: What is cloudflare EXACTLY and why does it going down take down like 80 percent of the internet","ELI5: Why do prostate cancer checks still need a finger in the butt?","ELI5: Why are the screens in even luxury cars often so laggy? What prevents them from just investing a couple hundred more $ to install a faster chip?","ELI5 : If em dashes (—) aren’t quite common on the Internet and in social media, then how do LLMs like ChatGPT use a lot of them?","ELI5: Why aren’t viruses “alive”","ELI5 - What makes an ADHD brain process the world so differently","ELI5 Why did Radio Shack go out of business?","ELI5: Why is it good for your cardiovascular health to increase heart rate via exercise, but harmful to increase heart rate via stimulants?","ELI5 how Einstein figured out that time slows down the faster you travel","ELI5: If water makes you urinate more, which causes kidneys to do more work, does that mean high water consumption damages kidneys long-term? If not, why not?","ELI5: Why do car dealers say buying the car when the lease ends would be worse than buying new?","ELI5: why aren't most wounds between your buttocks fatal?","ELI5: How does the US have such amazing diplomacy with Japan when we dropped two nuclear bombs on them? How did we build it back so quickly?","ELI5: How is blackjack \"rigged\" for the casino?","ELI5: How does a bomber plane not get caught in the explosion after dropping a nuclear bomb?","ELI5: Why do reporters in the same city as the studio respond several seconds later, while people on Zoom across the world respond almost instantly?","ELI5: Why can humans run 5km a day but racehorses only run 1-2km every couple weeks?","ELI5: How does a US police officer issuing a ticket by the side of the road instantly have a court date and time for the suspect?","ELI5: Why do Africa and Asia have an abundance of large animals/predators but the Americas and Europe really don’t?","ELI5: If unboiled water going into your nose is risky, then shouldn’t we not swim in a lake or river?","ELI5: If Fentanyl is so deadly how do the clandestine labs manufacture it, smugglers transport it and dealers handle it without killing everyone involved?","ELI5: Why isn’t all the data from the black box on airplanes get uploaded via satellite internet in real time to an airline server negating the need to find the black box if there’s an accident?","ELI5 Why does rabies have a near 100% fatality rate?","ELI5: Why does our body seem to know almost instantly when we’ve had enough water, but takes way longer to realize we’ve eaten enough food and aren’t hungry anymore?","ELI5: If you think about it, why do teeth need so much care? It feels like they kind of go against natural selection, especially when you compare them to how well the rest of our body maintains itself.","ELI5: Why can other carnivores eat raw meat but humans are so prone to infections?","ELI5 why places like nightclubs, tattooists, bar etc won’t accept IDs that are out of date? I’m not going to suddenly get any younger.","ELI5: Why can't we drop a wire with a camera and an LED light to the bottom of the ocean?","ELI5: How do babies breathe inside the womb when its lungs are entirely filled with fluids?","ELI5: What is deli turkey?","ELI5: why do property investors prefer houses standing empty and earning them no money to lowering rent so that people can afford to move in there?","ELI5: If the B2 looks like a small bird on radar, doesn’t it look like a small bird flying at 600mph?","ELI5: How was Vietnam able to defeat the US in the Vietnam War?","ELI5 Is all power generation really just making a turbine spin?","ELI5 how is masking for autistic people different from impulse control?","ELI5: Why has rabies not entirely decimated the world?","ELI5: Fentanyl and related drugs can sometimes cause the user to fold over while standing…why don’t they just sit down? Am I missing something?","Eli5, file compression, how can 5gb file can be compressed to 50mb and decompresses back to normal?","ELI5 : What happens if someone needs an emergency colonoscopy during an ER visit or other acute situation. They obviously aren't \"prepped\" with an empty colon. Can they clean out a bowel instantly if needed?","ELI5: Why can our bodies handle walking for miles, but standing still for a short while feels tiring and uncomfortable?","ELI5 why a second is defined as 197 billion oscillations of a cesium atom?","ELI5: Why does armpit sweat smell so much stronger than sweat from other parts of the body, like your back?","ELI5: Why can't we digest our own blood?","ELI5: H-bombs can reach 300 million Kelvin during detonation; the sun’s surface is 5772 Kelvin. Why can’t we get anywhere near the sun, but a H-bomb wouldn’t burn up the earth?","ELI5: How do they keep managing to make computers faster every year without hitting a wall? For example, why did we not have RTX 5090 level GPUs 10 years ago? What do we have now that we did not have back then, and why did we not have it back then, and why do we have it now?","ELI5 How the heck can the US bunker buster bomb go 200’ underground before it explodes?","ELI5: Can beer hydrate you indefinitely?","ELI5: Why have so many animals evolved to have exactly 2 eyes?","ELI5: Why are the seatbelts in airplane like the way they are (waist to waist) and not the way we have in cars (diagonally shoulder to waist)?","Eli5: how did 350 degrees become such a standard in all thing baking and roasting etc…?","ELI5 How protective are those padded bomb squad suits really?","ELI5: Why do animals all seem to like getting their chins/necks scratched?","ELI5: What actually happens when someone dies in their sleep?","ELI5: If dogs have such great sense of smell, why do they have to get their noses right up against another dog's butt?","ELI5: Why do Stars take so long to burn all their fuel, i know its a lot of fuel, but why doesnt it all burn about the same time? Like when im throwing something in a firepit","ELI5 why men go bald but women typically don't. Can evolution explain things that occur after an organism leaves its reproductive age?","ELI5: How do people die from gunshot or stab wounds days later?","ELI5 'The Panama Papers' and why it fizzled out so quickly?","ELI5: How do our organs sit inside our body if not soaked in blood?","ELI5: Why is it comfortable to sit in positions that are bad for you? Why do we frequently have bad posture?","ELI5 Why do some trees have fruits with a rewarding taste like saying \"come back again :)\" and some others have fruits with a punishing taste and even protection around the fruit like \"don't u even dare eat my fruits! >:/\"","ELI5: Why do so many websites care that you're using a VPN?","ELI5: Why does ice cream seem soft the first time you open it but it gets really hard the next time you take it out of the freezer?","ELI5: I learned that cpr is not, as usually assumed, for bringing people back to life, but for keeping the blood flowing until the medics arrive for reanimating. But now I realized I saw a lot of videos where especially animals where revived by cpr? So what is the chance of reviving someone with cpr","ELI5: Do we need to clean our ears?","ELI5: Why is a grenade more dangerous underwater than on land?","ELI5: Why can’t you buy a car directly from the company that makes it?","ELI5 Why does our stomach growl when we’re hungry?","ELI5: Why can't / don't LLMs say \"I don't know\" or ask back clarifying questions, instead of hallucinating?","eli5: Why do elderly people have a distinct odor?","ELI5: How do “buy now pay later” companies make money if there’s no interest","ELI5 Why do we throw up when we are extremely exhausted eg from a marathon?","ELI5: why do some books have pages that read: “this page has intentionally been left blank”","ELI5: Why do phones and EVs say to keep the battery around 20–80%? What’s physically happening at the extremes that wears batteries faster?","ELI5: why did we use mothball in 90s, but we don't use them now?","ELI5: Why do we do root canals instead of just pulling a tooth?","ELI5: Why dont MRIs rip the iron out of your body? Especially when iron deposits are present.","ELI5: Humans have lived on Earth for millions of years, so why haven’t we adapted to the harmful rays of the sun?","ELI5: What exactly is \"time blindness\" and how is it an actual thing?"]
pages/demos/accordion.ts:1:import { layout, prepare, type PreparedText } from '../../src/layout.ts'
pages/demos/accordion.ts:49: 'We learned the hard way that a giant native scroll range can dominate everything else. The bug looked like DOM churn, then like pooling, then like rendering pressure, until the repros were stripped down enough to show the real limit. That changed the fix completely: simplify the DOM, keep virtualization honest, and stop hiding the worst-case path behind caches that only make the common frame look cheaper.',
pages/demos/accordion.ts:68:const preparedCache = {
pages/demos/accordion.ts:137: if (preparedCache.font === font) return
pages/demos/accordion.ts:138: preparedCache.font = font
pages/demos/accordion.ts:139: preparedCache.items = items.map(item => prepare(item.text, font))
pages/demos/accordion.ts:207: const metrics = layout(preparedCache.items[index]!, contentWidth, lineHeight)
pages/demos/variable-typographic-ascii.html:19: .comparison { display: flex; gap: 28px; flex-wrap: wrap; justify-content: center; }
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "sed -n '1,240p' pages/demos/masonry/index.ts"
Chunk ID: 732281
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 1159
Output:
import { prepare, layout, type PreparedText } from '../../../src/layout.ts'
import rawThoughts from './shower-thoughts.json'
// --- config ---
const font = '15px "Helvetica Neue", Helvetica, Arial, sans-serif'
const lineHeight = 22
const cardPadding = 16
const gap = 12
const maxColWidth = 400
const singleColumnMaxViewportWidth = 520
type Card = {
text: string
prepared: PreparedText
}
type PositionedCard = {
cardIndex: number
x: number
y: number
h: number
}
type LayoutState = {
colWidth: number
contentHeight: number
positionedCards: PositionedCard[]
}
type State = {
cards: Card[]
}
// --- prepare all texts upfront ---
const st: State = {
cards: rawThoughts.map(text => ({
text,
prepared: prepare(text, font),
})),
}
type DomCache = {
container: HTMLDivElement // cache lifetime: same as app
cards: Array // cache lifetime: on visibility changes
}
const domCache: DomCache = {
container: document.createElement('div'),
cards: [],
}
domCache.container.style.position = 'relative'
document.body.appendChild(domCache.container)
function computeLayout(windowWidth: number): LayoutState {
let colCount: number
let colWidth: number
if (windowWidth <= singleColumnMaxViewportWidth) {
colCount = 1
colWidth = Math.min(maxColWidth, windowWidth - gap * 2)
} else {
const minColWidth = 100 + windowWidth * 0.1
colCount = Math.max(2, Math.floor((windowWidth + gap) / (minColWidth + gap)))
colWidth = Math.min(maxColWidth, (windowWidth - (colCount + 1) * gap) / colCount)
}
const textWidth = colWidth - cardPadding * 2
const contentWidth = colCount * colWidth + (colCount - 1) * gap
const offsetLeft = (windowWidth - contentWidth) / 2
const colHeights = new Float64Array(colCount)
for (let c = 0; c < colCount; c++) colHeights[c] = gap
const positionedCards: PositionedCard[] = []
for (let i = 0; i < st.cards.length; i++) {
let shortest = 0
for (let c = 1; c < colCount; c++) {
if (colHeights[c]! < colHeights[shortest]!) shortest = c
}
const { height } = layout(st.cards[i]!.prepared, textWidth, lineHeight)
const totalH = height + cardPadding * 2
positionedCards.push({
cardIndex: i,
x: offsetLeft + shortest * (colWidth + gap),
y: colHeights[shortest]!,
h: totalH,
})
colHeights[shortest]! += totalH + gap
}
let contentHeight = 0
for (let c = 0; c < colCount; c++) {
if (colHeights[c]! > contentHeight) contentHeight = colHeights[c]!
}
return { colWidth, contentHeight, positionedCards }
}
function getOrCreateCardNode(cardIndex: number): HTMLDivElement {
const existingNode = domCache.cards[cardIndex]
if (existingNode) return existingNode
const node = document.createElement('div')
node.className = 'card'
node.textContent = st.cards[cardIndex]!.text
domCache.container.appendChild(node)
domCache.cards[cardIndex] = node
return node
}
// --- events ---
window.addEventListener('resize', () => scheduleRender())
window.addEventListener('scroll', () => scheduleRender(), true)
let scheduledRaf: number | null = null
function scheduleRender() {
if (scheduledRaf != null) return
scheduledRaf = requestAnimationFrame(function renderAndMaybeScheduleAnotherRender() {
scheduledRaf = null
render()
})
}
function render() {
// --- DOM reads ---
const windowWidth = document.documentElement.clientWidth
const windowHeight = document.documentElement.clientHeight
const scrollTop = window.scrollY
const layoutState = computeLayout(windowWidth)
domCache.container.style.height = `${layoutState.contentHeight}px`
// --- visibility + DOM writes (single pass) ---
const viewTop = scrollTop - 200
const viewBottom = scrollTop + windowHeight + 200
const visibleFlags = new Uint8Array(st.cards.length)
for (let i = 0; i < layoutState.positionedCards.length; i++) {
const positionedCard = layoutState.positionedCards[i]!
if (positionedCard.y > viewBottom || positionedCard.y + positionedCard.h < viewTop) continue
visibleFlags[positionedCard.cardIndex] = 1
const node = getOrCreateCardNode(positionedCard.cardIndex)
node.style.left = `${positionedCard.x}px`
node.style.top = `${positionedCard.y}px`
node.style.width = `${layoutState.colWidth}px`
node.style.height = `${positionedCard.h}px`
}
for (let cardIndex = 0; cardIndex < domCache.cards.length; cardIndex++) {
const node = domCache.cards[cardIndex]
if (node && visibleFlags[cardIndex] === 0) {
node.remove()
domCache.cards[cardIndex] = undefined
}
}
}
scheduleRender()
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "sed -n '1,260p' pages/demos/wrap-geometry.ts"
Chunk ID: 6d727a
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 1982
Output:
export type Rect = {
x: number
y: number
width: number
height: number
}
export type Interval = {
left: number
right: number
}
export type Point = {
x: number
y: number
}
export type WrapHullMode = 'mean' | 'envelope'
export type WrapHullOptions = {
smoothRadius: number
mode: WrapHullMode
convexify?: boolean
}
const wrapHullByKey = new Map>()
export function getWrapHull(src: string, options: WrapHullOptions): Promise {
const key = `${src}::${options.mode}::${options.smoothRadius}::${options.convexify ? 'convex' : 'raw'}`
const cached = wrapHullByKey.get(key)
if (cached !== undefined) return cached
const promise = makeWrapHull(src, options)
wrapHullByKey.set(key, promise)
return promise
}
export function transformWrapPoints(points: Point[], rect: Rect, angle: number): Point[] {
if (angle === 0) {
return points.map(point => ({
x: rect.x + point.x * rect.width,
y: rect.y + point.y * rect.height,
}))
}
const centerX = rect.x + rect.width / 2
const centerY = rect.y + rect.height / 2
const cos = Math.cos(angle)
const sin = Math.sin(angle)
return points.map(point => {
const localX = (point.x - 0.5) * rect.width
const localY = (point.y - 0.5) * rect.height
return {
x: centerX + localX * cos - localY * sin,
y: centerY + localX * sin + localY * cos,
}
})
}
export function isPointInPolygon(points: Point[], x: number, y: number): boolean {
let inside = false
for (let index = 0, prev = points.length - 1; index < points.length; prev = index++) {
const a = points[index]!
const b = points[prev]!
const intersects =
((a.y > y) !== (b.y > y)) &&
(x < ((b.x - a.x) * (y - a.y)) / (b.y - a.y) + a.x)
if (intersects) inside = !inside
}
return inside
}
export function getPolygonIntervalForBand(
points: Point[],
bandTop: number,
bandBottom: number,
horizontalPadding: number,
verticalPadding: number,
): Interval | null {
const sampleTop = bandTop - verticalPadding
const sampleBottom = bandBottom + verticalPadding
const startY = Math.floor(sampleTop)
const endY = Math.ceil(sampleBottom)
let left = Infinity
let right = -Infinity
for (let y = startY; y <= endY; y++) {
const xs = getPolygonXsAtY(points, y + 0.5)
for (let index = 0; index + 1 < xs.length; index += 2) {
const runLeft = xs[index]!
const runRight = xs[index + 1]!
if (runLeft < left) left = runLeft
if (runRight > right) right = runRight
}
}
if (!Number.isFinite(left) || !Number.isFinite(right)) return null
return { left: left - horizontalPadding, right: right + horizontalPadding }
}
export function getRectIntervalsForBand(
rects: Rect[],
bandTop: number,
bandBottom: number,
horizontalPadding: number,
verticalPadding: number,
): Interval[] {
const intervals: Interval[] = []
for (let index = 0; index < rects.length; index++) {
const rect = rects[index]!
if (bandBottom <= rect.y - verticalPadding || bandTop >= rect.y + rect.height + verticalPadding) continue
intervals.push({
left: rect.x - horizontalPadding,
right: rect.x + rect.width + horizontalPadding,
})
}
return intervals
}
// Given one allowed horizontal interval and a set of blocked intervals,
// carve out the remaining usable text slots for one text line band.
//
// Example:
// - base: 80..420
// - blocked: 200..310
// - result: 80..200, 310..420
//
// On the dynamic-layout page, the base interval is one full column row,
// the blocked intervals come from the title/logo shapes at that band,
// and the returned intervals are the candidate text slots for that row.
//
// This helper is intentionally page-oriented, not pure geometry:
// it also discards absurdly narrow leftover slivers that we would never
// want to hand to text layout.
export function carveTextLineSlots(base: Interval, blocked: Interval[]): Interval[] {
let slots: Interval[] = [base]
for (let blockedIndex = 0; blockedIndex < blocked.length; blockedIndex++) {
const interval = blocked[blockedIndex]!
const next: Interval[] = []
for (let slotIndex = 0; slotIndex < slots.length; slotIndex++) {
const slot = slots[slotIndex]!
if (interval.right <= slot.left || interval.left >= slot.right) {
next.push(slot)
continue
}
if (interval.left > slot.left) next.push({ left: slot.left, right: interval.left })
if (interval.right < slot.right) next.push({ left: interval.right, right: slot.right })
}
slots = next
}
return slots.filter(slot => slot.right - slot.left >= 24)
}
async function makeWrapHull(src: string, options: WrapHullOptions): Promise {
const image = new Image()
image.src = src
await image.decode()
const maxDimension = 320
const aspect = image.naturalWidth / image.naturalHeight
const width = aspect >= 1
? maxDimension
: Math.max(64, Math.round(maxDimension * aspect))
const height = aspect >= 1
? Math.max(64, Math.round(maxDimension / aspect))
: maxDimension
const canvas = new OffscreenCanvas(width, height)
const ctx = canvas.getContext('2d')
if (ctx === null) throw new Error('2d context unavailable')
ctx.clearRect(0, 0, width, height)
ctx.drawImage(image, 0, 0, width, height)
const { data } = ctx.getImageData(0, 0, width, height)
const lefts: Array = new Array(height).fill(null)
const rights: Array = new Array(height).fill(null)
const alphaThreshold = 12
for (let y = 0; y < height; y++) {
let left = -1
let right = -1
for (let x = 0; x < width; x++) {
const alpha = data[(y * width + x) * 4 + 3]!
if (alpha < alphaThreshold) continue
if (left === -1) left = x
right = x
}
if (left !== -1 && right !== -1) {
lefts[y] = left
rights[y] = right + 1
}
}
const validRows: number[] = []
for (let y = 0; y < height; y++) {
if (lefts[y] !== null && rights[y] !== null) validRows.push(y)
}
if (validRows.length === 0) throw new Error(`No opaque pixels found in ${src}`)
let boundLeft = Infinity
let boundRight = -Infinity
const boundTop = validRows[0]!
const boundBottom = validRows[validRows.length - 1]!
for (let index = 0; index < validRows.length; index++) {
const y = validRows[index]!
const left = lefts[y]!
const right = rights[y]!
if (left < boundLeft) boundLeft = left
if (right > boundRight) boundRight = right
}
const boundWidth = Math.max(1, boundRight - boundLeft)
const boundHeight = Math.max(1, boundBottom - boundTop)
const smoothedLefts: number[] = new Array(height).fill(0)
const smoothedRights: number[] = new Array(height).fill(0)
for (let index = 0; index < validRows.length; index++) {
const y = validRows[index]!
let leftSum = 0
let rightSum = 0
let count = 0
let leftEdge = Infinity
let rightEdge = -Infinity
for (let offset = -options.smoothRadius; offset <= options.smoothRadius; offset++) {
const sampleIndex = y + offset
if (sampleIndex < 0 || sampleIndex >= height) continue
const left = lefts[sampleIndex]
const right = rights[sampleIndex]
if (left == null || right == null) continue
leftSum += left
rightSum += right
if (left < leftEdge) leftEdge = left
if (right > rightEdge) rightEdge = right
count++
}
if (count === 0) {
smoothedLefts[y] = 0
smoothedRights[y] = width
continue
}
switch (options.mode) {
case 'envelope':
smoothedLefts[y] = leftEdge
smoothedRights[y] = rightEdge
break
case 'mean':
smoothedLefts[y] = leftSum / count
smoothedRights[y] = rightSum / count
break
}
}
const step = Math.max(1, Math.floor(validRows.length / 52))
const sampledRows: number[] = []
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "sed -n '1,260p' pages/demos/rich-note.ts"
Chunk ID: d20ce6
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 1984
Output:
import {
layoutNextLine,
prepareWithSegments,
walkLineRanges,
type LayoutCursor,
type PreparedTextWithSegments,
} from '../../src/layout.ts'
type TextStyleName = 'body' | 'link' | 'code'
type ChipTone = 'mention' | 'status' | 'priority' | 'time' | 'count'
type RichInlineSpec =
| { kind: 'text'; text: string; style: TextStyleName }
| { kind: 'chip'; label: string; tone: ChipTone }
type TextStyleModel = {
className: string
chromeWidth: number
font: string
}
type TextInlineItem = {
kind: 'text'
className: string
chromeWidth: number
endCursor: LayoutCursor
fullText: string
fullWidth: number
leadingGap: number
prepared: PreparedTextWithSegments
}
type ChipInlineItem = {
kind: 'chip'
className: string
leadingGap: number
text: string
width: number
}
type InlineItem = TextInlineItem | ChipInlineItem
type LineFragment = {
className: string
leadingGap: number
text: string
}
type RichLine = {
fragments: LineFragment[]
}
type State = {
events: {
sliderValue: number | null
}
requestedWidth: number
}
const BODY_FONT = '500 17px "Helvetica Neue", Helvetica, Arial, sans-serif'
const LINK_FONT = '600 17px "Helvetica Neue", Helvetica, Arial, sans-serif'
const CODE_FONT = '600 14px "SF Mono", ui-monospace, Menlo, Monaco, monospace'
const CHIP_FONT = '700 12px "Helvetica Neue", Helvetica, Arial, sans-serif'
const TEXT_STYLES = {
body: {
className: 'frag frag--body',
chromeWidth: 0,
font: BODY_FONT,
},
code: {
className: 'frag frag--code',
chromeWidth: 14,
font: CODE_FONT,
},
link: {
className: 'frag frag--link',
chromeWidth: 0,
font: LINK_FONT,
},
} satisfies Record
const CHIP_CLASS_NAMES = {
count: 'frag chip chip--count',
mention: 'frag chip chip--mention',
priority: 'frag chip chip--priority',
status: 'frag chip chip--status',
time: 'frag chip chip--time',
} satisfies Record
const LINE_START_CURSOR: LayoutCursor = { segmentIndex: 0, graphemeIndex: 0 }
const LINE_HEIGHT = 34
const LAST_LINE_BLOCK_HEIGHT = 24
const NOTE_SHELL_CHROME_X = 40
const BODY_MIN_WIDTH = 260
const BODY_DEFAULT_WIDTH = 516
const BODY_MAX_WIDTH = 760
const PAGE_MARGIN = 28
const CHIP_CHROME_WIDTH = 22
const UNBOUNDED_WIDTH = 100_000
const collapsedSpaceWidthCache = new Map()
const INLINE_BOUNDARY_GAP = measureCollapsedSpaceWidth(BODY_FONT)
const INLINE_SPECS: RichInlineSpec[] = [
{ kind: 'text', text: 'Ship ', style: 'body' },
{ kind: 'chip', label: '@maya', tone: 'mention' },
{ kind: 'text', text: "'s ", style: 'body' },
{ kind: 'text', text: 'rich-note', style: 'code' },
{ kind: 'text', text: ' card once ', style: 'body' },
{ kind: 'text', text: 'pre-wrap', style: 'code' },
{ kind: 'text', text: ' lands. Status ', style: 'body' },
{ kind: 'chip', label: 'blocked', tone: 'status' },
{ kind: 'text', text: ' by ', style: 'body' },
{ kind: 'text', text: 'vertical text', style: 'link' },
{ kind: 'text', text: ' research, but 北京 copy and Arabic QA are both green ✅. Keep ', style: 'body' },
{ kind: 'chip', label: 'جاهز', tone: 'status' },
{ kind: 'text', text: ' for ', style: 'body' },
{ kind: 'text', text: 'Cmd+K', style: 'code' },
{ kind: 'text', text: ' docs; the review bundle now includes 中文 labels, عربي fallback, and one more launch pass 🚀 for ', style: 'body' },
{ kind: 'chip', label: 'Fri 2:30 PM', tone: 'time' },
{ kind: 'text', text: '. Keep ', style: 'body' },
{ kind: 'text', text: 'layoutNextLine()', style: 'code' },
{ kind: 'text', text: ' public, tag this ', style: 'body' },
{ kind: 'chip', label: 'P1', tone: 'priority' },
{ kind: 'text', text: ', keep ', style: 'body' },
{ kind: 'chip', label: '3 reviewers', tone: 'count' },
{ kind: 'text', text: ', and route feedback to ', style: 'body' },
{ kind: 'text', text: 'design sync', style: 'link' },
{ kind: 'text', text: '.', style: 'body' },
]
const domCache = {
root: document.documentElement, // cache lifetime: page
noteBody: getRequiredDiv('note-body'), // cache lifetime: page
widthSlider: getRequiredInput('width-slider'), // cache lifetime: page
widthValue: getRequiredSpan('width-value'), // cache lifetime: page
}
const items = prepareInlineItems(INLINE_SPECS)
const st: State = {
events: {
sliderValue: null,
},
requestedWidth: BODY_DEFAULT_WIDTH,
}
let scheduledRaf: number | null = null
domCache.widthSlider.addEventListener('input', () => {
st.events.sliderValue = Number.parseInt(domCache.widthSlider.value, 10)
scheduleRender()
})
window.addEventListener('resize', () => scheduleRender())
scheduleRender()
function getRequiredDiv(id: string): HTMLDivElement {
const element = document.getElementById(id)
if (!(element instanceof HTMLDivElement)) throw new Error(`#${id} not found`)
return element
}
function getRequiredInput(id: string): HTMLInputElement {
const element = document.getElementById(id)
if (!(element instanceof HTMLInputElement)) throw new Error(`#${id} not found`)
return element
}
function getRequiredSpan(id: string): HTMLSpanElement {
const element = document.getElementById(id)
if (!(element instanceof HTMLSpanElement)) throw new Error(`#${id} not found`)
return element
}
function scheduleRender(): void {
if (scheduledRaf !== null) return
scheduledRaf = requestAnimationFrame(function renderRichNoteDemo() {
scheduledRaf = null
render()
})
}
function measureSingleLineWidth(prepared: PreparedTextWithSegments): number {
let maxWidth = 0
walkLineRanges(prepared, UNBOUNDED_WIDTH, line => {
if (line.width > maxWidth) maxWidth = line.width
})
return maxWidth
}
function measureCollapsedSpaceWidth(font: string): number {
const cached = collapsedSpaceWidthCache.get(font)
if (cached !== undefined) return cached
const joinedWidth = measureSingleLineWidth(prepareWithSegments('A A', font))
const compactWidth = measureSingleLineWidth(prepareWithSegments('AA', font))
const collapsedWidth = Math.max(0, joinedWidth - compactWidth)
collapsedSpaceWidthCache.set(font, collapsedWidth)
return collapsedWidth
}
function prepareInlineItems(specs: RichInlineSpec[]): InlineItem[] {
const items: InlineItem[] = []
let pendingGap = 0
for (let index = 0; index < specs.length; index++) {
const spec = specs[index]!
switch (spec.kind) {
case 'chip': {
const prepared = prepareWithSegments(spec.label, CHIP_FONT)
items.push({
kind: 'chip',
className: CHIP_CLASS_NAMES[spec.tone],
leadingGap: pendingGap,
text: spec.label,
width: Math.ceil(measureSingleLineWidth(prepared)) + CHIP_CHROME_WIDTH,
})
pendingGap = 0
break
}
case 'text': {
const carryGap = pendingGap
const hasLeadingWhitespace = /^\s/.test(spec.text)
const hasTrailingWhitespace = /\s$/.test(spec.text)
const trimmedText = spec.text.trim()
pendingGap = hasTrailingWhitespace ? INLINE_BOUNDARY_GAP : 0
if (trimmedText.length === 0) break
const style = TEXT_STYLES[spec.style]
const prepared = prepareWithSegments(trimmedText, style.font)
const wholeLine = layoutNextLine(prepared, LINE_START_CURSOR, UNBOUNDED_WIDTH)
if (wholeLine === null) break
items.push({
kind: 'text',
className: style.className,
chromeWidth: style.chromeWidth,
endCursor: wholeLine.end,
fullText: wholeLine.text,
fullWidth: wholeLine.width,
leadingGap: carryGap > 0 || hasLeadingWhitespace ? INLINE_BOUNDARY_GAP : 0,
prepared,
})
break
}
}
}
return items
}
function cursorsMatch(a: LayoutCursor, b: LayoutCursor): boolean {
return a.segmentIndex === b.segmentIndex && a.graphemeIndex === b.graphemeIndex
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "sed -n '1,260p' pages/demos/editorial-engine.ts",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "sed -n '260,520p' pages/demos/editorial-engine.ts",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "sed -n '1,260p' pages/demos/dynamic-layout.ts",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "sed -n '261,520p' pages/demos/dynamic-layout.ts",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "sed -n '1,260p' pages/demos/editorial-engine.ts"
Chunk ID: 05364a
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 4447
Output:
import {
layoutNextLine,
layoutWithLines,
prepareWithSegments,
walkLineRanges,
type LayoutCursor,
type PreparedTextWithSegments,
} from '../../src/layout.ts'
const BODY_FONT = '18px "Iowan Old Style", "Palatino Linotype", "Book Antiqua", Palatino, serif'
const BODY_LINE_HEIGHT = 30
const HEADLINE_FONT_FAMILY = '"Iowan Old Style", "Palatino Linotype", "Book Antiqua", Palatino, serif'
const HEADLINE_TEXT = 'THE FUTURE OF TEXT LAYOUT IS NOT CSS'
const GUTTER = 48
const COL_GAP = 40
const BOTTOM_GAP = 20
const DROP_CAP_LINES = 3
const MIN_SLOT_WIDTH = 50
const NARROW_BREAKPOINT = 760
const NARROW_GUTTER = 20
const NARROW_COL_GAP = 20
const NARROW_BOTTOM_GAP = 16
const NARROW_ORB_SCALE = 0.58
const NARROW_ACTIVE_ORBS = 3
type Interval = {
left: number
right: number
}
type PositionedLine = {
x: number
y: number
width: number
text: string
}
type TextProjection = {
headlineLeft: number
headlineTop: number
headlineFont: string
headlineLineHeight: number
headlineLines: PositionedLine[]
bodyFont: string
bodyLineHeight: number
bodyLines: PositionedLine[]
pullquoteFont: string
pullquoteLineHeight: number
pullquoteLines: PositionedLine[]
}
type CircleObstacle = {
cx: number
cy: number
r: number
hPad: number
vPad: number
}
type RectObstacle = {
x: number
y: number
w: number
h: number
}
type PullquotePlacement = {
colIdx: number
yFrac: number
wFrac: number
side: 'left' | 'right'
}
type PullquoteRect = RectObstacle & {
lines: PositionedLine[]
colIdx: number
}
type OrbColor = [number, number, number]
type OrbDefinition = {
fx: number
fy: number
r: number
vx: number
vy: number
color: OrbColor
}
type Orb = {
x: number
y: number
r: number
vx: number
vy: number
paused: boolean
}
type HeadlineFit = {
fontSize: number
lines: PositionedLine[]
}
type PullquoteSpec = {
prepared: PreparedTextWithSegments
placement: PullquotePlacement
}
type PointerSample = {
x: number
y: number
}
type PointerState = {
x: number
y: number
}
type DragState = {
orbIndex: number
startPointerX: number
startPointerY: number
startOrbX: number
startOrbY: number
}
type InteractionMode = 'idle' | 'text-select'
type AppState = {
orbs: Orb[]
pointer: PointerState
drag: DragState | null
interactionMode: InteractionMode
selectionActive: boolean
events: {
pointerDown: PointerSample | null
pointerMove: PointerSample | null
pointerUp: PointerSample | null
}
lastFrameTime: number | null
}
function getRequiredDiv(id: string): HTMLDivElement {
const element = document.getElementById(id)
if (!(element instanceof HTMLDivElement)) throw new Error(`#${id} not found`)
return element
}
function carveTextLineSlots(base: Interval, blocked: Interval[]): Interval[] {
let slots = [base]
for (let blockedIndex = 0; blockedIndex < blocked.length; blockedIndex++) {
const interval = blocked[blockedIndex]!
const next: Interval[] = []
for (let slotIndex = 0; slotIndex < slots.length; slotIndex++) {
const slot = slots[slotIndex]!
if (interval.right <= slot.left || interval.left >= slot.right) {
next.push(slot)
continue
}
if (interval.left > slot.left) next.push({ left: slot.left, right: interval.left })
if (interval.right < slot.right) next.push({ left: interval.right, right: slot.right })
}
slots = next
}
return slots.filter(slot => slot.right - slot.left >= MIN_SLOT_WIDTH)
}
function circleIntervalForBand(
cx: number,
cy: number,
r: number,
bandTop: number,
bandBottom: number,
hPad: number,
vPad: number,
): Interval | null {
const top = bandTop - vPad
const bottom = bandBottom + vPad
if (top >= cy + r || bottom <= cy - r) return null
const minDy = cy >= top && cy <= bottom ? 0 : cy < top ? top - cy : cy - bottom
if (minDy >= r) return null
const maxDx = Math.sqrt(r * r - minDy * minDy)
return { left: cx - maxDx - hPad, right: cx + maxDx + hPad }
}
const BODY_TEXT = `The web renders text through a pipeline that was designed thirty years ago for static documents. A browser loads a font, shapes the text into glyphs, measures their combined width, determines where lines break, and positions each line vertically. Every step depends on the previous one. Every step requires the rendering engine to consult its internal layout tree — a structure so expensive to maintain that browsers guard access to it behind synchronous reflow barriers that can freeze the main thread for tens of milliseconds at a time.
For a paragraph in a blog post, this pipeline is invisible. The browser loads, lays out, and paints before the reader’s eye has traveled from the address bar to the first word. But the web is no longer a collection of static documents. It is a platform for applications, and those applications need to know about text in ways the original pipeline never anticipated.
A messaging application needs to know the exact height of every message bubble before rendering a virtualized list. A masonry layout needs the height of every card to position them without overlap. An editorial page needs text to flow around images, advertisements, and interactive elements. A responsive dashboard needs to resize and reflow text in real time as the user drags a panel divider.
Every one of these operations requires text measurement. And every text measurement on the web today requires a synchronous layout reflow. The cost is devastating. Measuring the height of a single text block forces the browser to recalculate the position of every element on the page. When you measure five hundred text blocks in sequence, you trigger five hundred full layout passes. This pattern, known as layout thrashing, is the single largest source of jank on the modern web.
Chrome DevTools will flag it with angry red bars. Lighthouse will dock your performance score. But the developer has no alternative — CSS provides no API for computing text height without rendering it. The information is locked behind the DOM, and the DOM makes you pay for every answer.
Developers have invented increasingly desperate workarounds. Estimated heights replace real measurements with guesses, causing content to visibly jump when the guess is wrong. ResizeObserver watches elements for size changes, but it fires asynchronously and always at least one frame too late. IntersectionObserver tracks visibility but says nothing about dimensions. Content-visibility allows the browser to skip rendering off-screen elements, but it breaks scroll position and accessibility. Each workaround addresses one symptom while introducing new problems.
The CSS Shapes specification, finalized in 2014, was supposed to bring magazine-style text wrap to the web. It allows text to flow around a defined shape — a circle, an ellipse, a polygon, even an image alpha channel. On paper, it was the answer. In practice, it is remarkably limited. CSS Shapes only works with floated elements. Text can only wrap on one side of the shape. The shape must be defined statically in CSS — you cannot animate it or change it dynamically without triggering a full layout reflow. And because it operates within the browser’s layout engine, you have no access to the resulting line geometry. You cannot determine where each line of text starts and ends, how many lines were generated, or what the total height of the shaped text block is.
The editorial layouts we see in print magazines — text flowing around photographs, pull quotes interrupting the column, multiple columns with seamless text handoff — have remained out of reach for the web. Not because they are conceptually difficult, but because the performance cost of implementing them with DOM measurement makes them impractical. A two-column editorial layout that reflows text around three obstacle shapes requires measuring and positioning hundreds of text lines. At thirty milliseconds per measurement, this would take seconds — an eternity for a render frame.
What if text measurement did not require the DOM at all? What if you could compute exactly where every line of text would break, exactly how wide each line would be, and exactly how tall the entire text block would be, using nothing but arithmetic?
This is the core insight of pretext. The browser’s canvas API includes a measureText method that returns the width of any string in any font without triggering a layout reflow. Canvas measurement uses the same font engine as DOM rendering — the results are identical. But because it operates outside the layout tree, it carries no reflow penalty.
Pretext exploits this asymmetry. When text first appears, pretext measures every word once via canvas and caches the widths. After this preparation phase, layout is pure arithmetic: walk the cached widths, track the running line width, insert line breaks when the width exceeds the maximum, and sum the line heights. No DOM. No reflow. No layout tree access.
The performance improvement is not incremental. Measuring five hundred text blocks with DOM methods costs fifteen to thirty milliseconds and triggers five hundred layout reflows. With pretext, the same operation costs 0.05 milliseconds and triggers zero reflows. This is a three hundred to six hundred times improvement. But even that number understates the impact, because pretext’s cost does not scale with page complexity — it is independent of how many other elements exist on the page.
With DOM-free text measurement, an entire class of previously impractical interfaces becomes trivial. Text can flow around arbitrary shapes, not because the browser’s layout engine supports it, but because you control the line widths directly. For each line of text, you compute which horizontal intervals are blocked by obstacles, subtract them from the available width, and pass the remaining width to the layout engine. The engine returns the text that fits, and you position the line at the correct offset.
This is exactly what CSS Shapes tried to accomplish, but with none of its limitations. Obstacles can be any shape — rectangles, circles, arbitrary polygons, even the alpha channel of an image. Text wraps on both sides simultaneously. Obstacles can move, animate, or be dragged by the user, and the text reflows instantly because the layout computation takes less than a millisecond.
Shrinkwrap is another capability that CSS cannot express. Given a block of multiline text, what is the narrowest width that preserves the current line count? CSS offers fit-content, which works for single lines but always leaves dead space for multiline text. Pretext solves this with a binary search over widths: narrow until the line count increases, then back off. The result is the tightest possible bounding box — perfect for chat message bubbles, image captions, and tooltip text.
Virtualized text rendering becomes exact rather than estimated. A virtual list needs to know the height of items before they enter the viewport, so it can position them correctly and calculate scroll extent. Without pretext, you must either render items off-screen to measure them (defeating the purpose of virtualization) or estimate heights and accept visual jumping when items enter the viewport with different heights than predicted. Pretext computes exact heights without creating any DOM elements, enabling perfect virtualization with zero visual artifacts.
Multi-column text flow with cursor handoff is perhaps the most striking capability. The left column consumes text until it reaches the bottom, then hands its cursor to the right column. The right column picks up exactly where the left column stopped, with no duplication, no gap, and perfect line breaking at the column boundary. This is how newspapers and magazines work on paper, but it has never been achievable on the web without extreme hacks involving multiple elements, hidden overflow, and JavaScript-managed content splitting.
Pretext makes it trivial. Call layoutNextLine in a loop for the first column, using the column width. When the column is full, take the returned cursor and start a new loop for the second column. The cursor carries the exact position in the prepared text — which segment, which grapheme within that segment. The second column continues seamlessly from the first.
Adaptive headline sizing is a detail that separates professional typography from amateur layout. The headline should be as large as possible without breaking any word across lines. This requires a binary search: try a font size, measure the text, check if any line breaks occur within a word, and adjust. With DOM measurement, each iteration costs a reflow. With pretext, each iteration is a microsecond of arithmetic.
Real-time text reflow around animated obstacles is the ultimate stress test. The demonstration you are reading right now renders text that flows around multiple moving objects simultaneously, every frame, at sixty frames per second. Each frame, the layout engine computes obstacle intersections for every line of text, determines the available horizontal slots, lays out each line at the correct width and position, and updates the DOM with the results. The total computation time is typically under half a millisecond.
The glowing orbs drifting across this page are not decorative — they are the demonstration. Each orb is a circular obstacle. For every line of text, the engine checks whether the line’s vertical band intersects each orb. If it does, it computes the blocked horizontal interval and subtracts it from the available width. The remaining width might be split into two or more segments — and the engine fills every viable slot, flowing text on both sides of the obstacle simultaneously. This is something CSS Shapes cannot do at all.
All of this runs without a single DOM measurement. The line positions, widths, and text contents are computed entirely in JavaScript using cached font metrics. The only DOM writes are setting the left, top, and textContent of each line element — the absolute minimum required to show text on screen. The browser never needs to compute layout because all positioning is explicit.
This performance characteristic has profound implications for the web platform. For thirty years, the browser has been the gatekeeper of text information. If you wanted to know anything about how text would render — its width, its height, where its lines break — you had to ask the browser, and the browser made you pay for the answer with a layout reflow. This created an artificial scarcity of text information that constrained what interfaces could do.
Pretext removes that constraint. Text information becomes abundant and cheap. You can ask how text would look at a thousand different widths in the time it used to take to ask about one. You can recompute text layout every frame, every drag event, every pixel of window resize, without any performance concern.
The implications extend beyond layout into composition. When you have instant text measurement, you can build compositing engines that combine text with graphics, animation, and interaction in ways that were previously reserved for game engines and native applications. Text becomes a first-class participant in the visual composition, not a static block that the rest of the interface must work around.
Imagine a data visualization where labels reflow around chart elements as the user zooms and pans. Imagine a collaborative document editor where text flows around embedded widgets, images, and annotations placed by other users, updating live as they move things around. Imagine a map application where place names wrap intelligently around geographic features rather than overlapping them. These are not hypothetical — they are engineering problems that become solvable when text measurement costs a microsecond instead of thirty milliseconds.
The open web deserves typography that matches its ambition. We build applications that rival native software in every dimension except text. Our animations are smooth, our interactions are responsive, our graphics are stunning — but our text sits in rigid boxes, unable to flow around obstacles, unable to adapt to dynamic layouts, unable to participate in the fluid compositions that define modern interface design.
This is what changes when text measurement becomes free. Not slightly better — categorically different. The interfaces that were too expensive to build become trivial. The layouts that existed only in print become interactive. The text that sat in boxes begins to flow.
The web has been waiting thirty years for this. A fifteen kilobyte library with zero dependencies delivers it. No browser API changes needed. No specification process. No multi-year standardization timeline. Just math, cached measurements, and the audacity to ask: what if we simply stopped asking the DOM?
Fifteen kilobytes. Zero dependencies. Zero DOM reads. And the text flows.`
const PULLQUOTE_TEXTS = [
'“The performance improvement is not incremental — it is categorical. 0.05ms versus 30ms. Zero reflows versus five hundred.”',
'“Text becomes a first-class participant in the visual composition — not a static block, but a fluid material that adapts in real time.”',
]
const stage = getRequiredDiv('stage')
const orbDefs: OrbDefinition[] = [
{ fx: 0.52, fy: 0.22, r: 110, vx: 24, vy: 16, color: [196, 163, 90] },
{ fx: 0.18, fy: 0.48, r: 85, vx: -19, vy: 26, color: [100, 140, 255] },
{ fx: 0.74, fy: 0.58, r: 95, vx: 16, vy: -21, color: [232, 100, 130] },
{ fx: 0.38, fy: 0.72, r: 75, vx: -26, vy: -14, color: [80, 200, 140] },
{ fx: 0.86, fy: 0.18, r: 65, vx: -13, vy: 19, color: [150, 100, 220] },
]
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "sed -n '260,520p' pages/demos/editorial-engine.ts"
Chunk ID: f55f76
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 2140
Output:
function createOrbEl(color: OrbColor): HTMLDivElement {
const element = document.createElement('div')
element.className = 'orb'
element.style.background = `radial-gradient(circle at 35% 35%, rgba(${color[0]},${color[1]},${color[2]},0.35), rgba(${color[0]},${color[1]},${color[2]},0.12) 55%, transparent 72%)`
element.style.boxShadow = `0 0 60px 15px rgba(${color[0]},${color[1]},${color[2]},0.18), 0 0 120px 40px rgba(${color[0]},${color[1]},${color[2]},0.07)`
stage.appendChild(element)
return element
}
const W0 = window.innerWidth
const H0 = window.innerHeight
await document.fonts.ready
const preparedBody = prepareWithSegments(BODY_TEXT, BODY_FONT)
const PQ_FONT = `italic 19px ${HEADLINE_FONT_FAMILY}`
const PQ_LINE_HEIGHT = 27
const preparedPullquotes = PULLQUOTE_TEXTS.map(text => prepareWithSegments(text, PQ_FONT))
const pullquoteSpecs: PullquoteSpec[] = [
{ prepared: preparedPullquotes[0]!, placement: { colIdx: 0, yFrac: 0.48, wFrac: 0.52, side: 'right' } },
{ prepared: preparedPullquotes[1]!, placement: { colIdx: 1, yFrac: 0.32, wFrac: 0.5, side: 'left' } },
]
const DROP_CAP_SIZE = BODY_LINE_HEIGHT * DROP_CAP_LINES - 4
const DROP_CAP_FONT = `700 ${DROP_CAP_SIZE}px ${HEADLINE_FONT_FAMILY}`
const DROP_CAP_TEXT = BODY_TEXT[0]!
const preparedDropCap = prepareWithSegments(DROP_CAP_TEXT, DROP_CAP_FONT)
let dropCapWidth = 0
walkLineRanges(preparedDropCap, 9999, line => {
dropCapWidth = line.width
})
const DROP_CAP_TOTAL_W = Math.ceil(dropCapWidth) + 10
const dropCapEl = document.createElement('div')
dropCapEl.className = 'drop-cap'
dropCapEl.textContent = DROP_CAP_TEXT
dropCapEl.style.font = DROP_CAP_FONT
dropCapEl.style.lineHeight = `${DROP_CAP_SIZE}px`
stage.appendChild(dropCapEl)
const linePool: HTMLSpanElement[] = []
const headlinePool: HTMLSpanElement[] = []
const pullquoteLinePool: HTMLSpanElement[] = []
const pullquoteBoxPool: HTMLDivElement[] = []
const domCache = {
stage, // cache lifetime: same as page
dropCap: dropCapEl, // cache lifetime: same as page
bodyLines: linePool, // cache lifetime: on body line-count changes
headlineLines: headlinePool, // cache lifetime: on headline line-count changes
pullquoteLines: pullquoteLinePool, // cache lifetime: on pullquote line-count changes
pullquoteBoxes: pullquoteBoxPool, // cache lifetime: on pullquote-count changes
orbs: orbDefs.map(definition => createOrbEl(definition.color)), // cache lifetime: same as orb defs
}
const st: AppState = {
orbs: orbDefs.map(definition => ({
x: definition.fx * W0,
y: definition.fy * H0,
r: definition.r,
vx: definition.vx,
vy: definition.vy,
paused: false,
})),
pointer: { x: -9999, y: -9999 },
drag: null,
interactionMode: 'idle',
selectionActive: false,
events: {
pointerDown: null,
pointerMove: null,
pointerUp: null,
},
lastFrameTime: null,
}
let committedTextProjection: TextProjection | null = null
function syncPool(pool: T[], count: number, create: () => T): void {
while (pool.length < count) {
const element = create()
stage.appendChild(element)
pool.push(element)
}
for (let index = 0; index < pool.length; index++) {
pool[index]!.style.display = index < count ? '' : 'none'
}
}
let cachedHeadlineWidth = -1
let cachedHeadlineHeight = -1
let cachedHeadlineMaxSize = -1
let cachedHeadlineFontSize = 24
let cachedHeadlineLines: PositionedLine[] = []
function fitHeadline(maxWidth: number, maxHeight: number, maxSize: number = 92): HeadlineFit {
if (maxWidth === cachedHeadlineWidth && maxHeight === cachedHeadlineHeight && maxSize === cachedHeadlineMaxSize) {
return { fontSize: cachedHeadlineFontSize, lines: cachedHeadlineLines }
}
cachedHeadlineWidth = maxWidth
cachedHeadlineHeight = maxHeight
cachedHeadlineMaxSize = maxSize
let lo = 20
let hi = maxSize
let best = lo
let bestLines: PositionedLine[] = []
while (lo <= hi) {
const size = Math.floor((lo + hi) / 2)
const font = `700 ${size}px ${HEADLINE_FONT_FAMILY}`
const lineHeight = Math.round(size * 0.93)
const prepared = prepareWithSegments(HEADLINE_TEXT, font)
let breaksWord = false
let lineCount = 0
walkLineRanges(prepared, maxWidth, line => {
lineCount++
if (line.end.graphemeIndex !== 0) breaksWord = true
})
const totalHeight = lineCount * lineHeight
if (!breaksWord && totalHeight <= maxHeight) {
best = size
const result = layoutWithLines(prepared, maxWidth, lineHeight)
bestLines = result.lines.map((line, index) => ({
x: 0,
y: index * lineHeight,
text: line.text,
width: line.width,
}))
lo = size + 1
} else {
hi = size - 1
}
}
cachedHeadlineFontSize = best
cachedHeadlineLines = bestLines
return { fontSize: best, lines: bestLines }
}
function layoutColumn(
prepared: PreparedTextWithSegments,
startCursor: LayoutCursor,
regionX: number,
regionY: number,
regionW: number,
regionH: number,
lineHeight: number,
circleObstacles: CircleObstacle[],
rectObstacles: RectObstacle[],
singleSlotOnly: boolean = false,
): { lines: PositionedLine[], cursor: LayoutCursor } {
let cursor: LayoutCursor = startCursor
let lineTop = regionY
const lines: PositionedLine[] = []
let textExhausted = false
while (lineTop + lineHeight <= regionY + regionH && !textExhausted) {
const bandTop = lineTop
const bandBottom = lineTop + lineHeight
const blocked: Interval[] = []
for (let obstacleIndex = 0; obstacleIndex < circleObstacles.length; obstacleIndex++) {
const obstacle = circleObstacles[obstacleIndex]!
const interval = circleIntervalForBand(
obstacle.cx,
obstacle.cy,
obstacle.r,
bandTop,
bandBottom,
obstacle.hPad,
obstacle.vPad,
)
if (interval !== null) blocked.push(interval)
}
for (let rectIndex = 0; rectIndex < rectObstacles.length; rectIndex++) {
const rect = rectObstacles[rectIndex]!
if (bandBottom <= rect.y || bandTop >= rect.y + rect.h) continue
blocked.push({ left: rect.x, right: rect.x + rect.w })
}
const slots = carveTextLineSlots({ left: regionX, right: regionX + regionW }, blocked)
if (slots.length === 0) {
lineTop += lineHeight
continue
}
const orderedSlots = singleSlotOnly
? [slots.reduce((best, slot) => {
const bestWidth = best.right - best.left
const slotWidth = slot.right - slot.left
if (slotWidth > bestWidth) return slot
if (slotWidth < bestWidth) return best
return slot.left < best.left ? slot : best
})]
: [...slots].sort((a, b) => a.left - b.left)
for (let slotIndex = 0; slotIndex < orderedSlots.length; slotIndex++) {
const slot = orderedSlots[slotIndex]!
const slotWidth = slot.right - slot.left
const line = layoutNextLine(prepared, cursor, slotWidth)
if (line === null) {
textExhausted = true
break
}
lines.push({
x: Math.round(slot.left),
y: Math.round(lineTop),
text: line.text,
width: line.width,
})
cursor = line.end
}
lineTop += lineHeight
}
return { lines, cursor }
}
function hitTestOrbs(orbs: Orb[], px: number, py: number, activeCount: number, radiusScale: number): number {
for (let index = activeCount - 1; index >= 0; index--) {
const orb = orbs[index]!
const radius = orb.r * radiusScale
const dx = px - orb.x
const dy = py - orb.y
if (dx * dx + dy * dy <= radius * radius) return index
}
return -1
}
function pointerSampleFromEvent(event: PointerEvent): PointerSample {
return { x: event.clientX, y: event.clientY }
}
function isSelectableTextTarget(target: EventTarget | null): boolean {
return target instanceof Element && target.closest('.line, .headline-line, .pullquote-line') !== null
}
function hasActiveTextSelection(): boolean {
const selection = window.getSelection()
return selection !== null && !selection.isCollapsed && selection.rangeCount > 0
}
function clearQueuedPointerEvents(): void {
st.events.pointerDown = null
st.events.pointerMove = null
st.events.pointerUp = null
}
function positionedLinesEqual(a: PositionedLine[], b: PositionedLine[]): boolean {
if (a.length !== b.length) return false
for (let index = 0; index < a.length; index++) {
const left = a[index]!
const right = b[index]!
if (
left.x !== right.x ||
left.y !== right.y ||
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "sed -n '1,260p' pages/demos/dynamic-layout.ts"
Chunk ID: b556bc
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 2109
Output:
/*
This page's made to show off our layout APIs:
- Title lines are measured and placed by our own layout engine, not inferred from DOM flow.
- Title font size is fit using repeated API calls so whole words survive.
- The title itself now participates in obstacle routing against the OpenAI logo.
- The author line is placed from the measured title result, and it also respects the OpenAI geometry.
- The body is one continuous text stream, not two unrelated excerpts.
- The left column consumes text first, and the right column resumes from the same cursor.
- The right column routes around:
- the actual title geometry
- the Anthropic/Claude logo hull
- the OpenAI logo when it intrudes
- The left column routes around the OpenAI logo hull.
- The logo contours are derived once from rasterized SVG alpha, cached, then transformed per render.
- Hover/click hit testing uses transformed logo hulls too.
- Clicking a logo rotates it, and the text reflows live around the rotated geometry.
- Obstacle exclusion is based on the full line band, not a single y sample.
- The page is a fixed-height viewport-bound spread:
- vertical resize changes reflow
- overflow after the second column truncates
- The first visible render now waits for both fonts and hull preload, so it uses the real geometry from the start.
- There is no DOM text measurement loop feeding layout.
*/
import { layoutNextLine, prepareWithSegments, walkLineRanges, type LayoutCursor, type PreparedTextWithSegments } from '../../src/layout.ts'
import { BODY_COPY } from './dynamic-layout-text.ts'
import openaiLogoUrl from '../assets/openai-symbol.svg'
import claudeLogoUrl from '../assets/claude-symbol.svg'
import {
carveTextLineSlots,
getPolygonIntervalForBand,
getRectIntervalsForBand,
getWrapHull,
isPointInPolygon,
transformWrapPoints,
type Interval,
type Point,
type Rect,
} from './wrap-geometry.ts'
const BODY_FONT = '20px "Iowan Old Style", "Palatino Linotype", "Book Antiqua", Palatino, serif'
const BODY_LINE_HEIGHT = 32
const CREDIT_TEXT = 'Leopold Aschenbrenner'
const CREDIT_FONT = '12px "Helvetica Neue", Helvetica, Arial, sans-serif'
const CREDIT_LINE_HEIGHT = 16
const HEADLINE_TEXT = 'SITUATIONAL AWARENESS: THE DECADE AHEAD'
const HEADLINE_FONT_FAMILY = '"Iowan Old Style", "Palatino Linotype", "Book Antiqua", Palatino, serif'
const HINT_PILL_SAFE_TOP = 72
const NARROW_BREAKPOINT = 760
const NARROW_COLUMN_MAX_WIDTH = 430
function resolveImportedAssetUrl(assetUrl: string): string {
if (/^(?:[a-z]+:)?\/\//i.test(assetUrl) || assetUrl.startsWith('data:') || assetUrl.startsWith('blob:')) {
return assetUrl
}
if (assetUrl.startsWith('/')) {
return new URL(assetUrl, window.location.origin).href
}
return new URL(assetUrl, import.meta.url).href
}
const OPENAI_LOGO_SRC = resolveImportedAssetUrl(openaiLogoUrl)
const CLAUDE_LOGO_SRC = resolveImportedAssetUrl(claudeLogoUrl)
type LogoKind = 'openai' | 'claude'
type SpinState = {
from: number
to: number
start: number
duration: number
}
type LogoAnimationState = {
angle: number
spin: SpinState | null
}
type PositionedLine = {
x: number
y: number
width: number
text: string
}
type ProjectedBodyLine = PositionedLine & {
className: string
}
type TextProjection = {
pageWidth: number
pageHeight: number
headlineFont: string
headlineLineHeight: number
headlineLines: PositionedLine[]
creditLeft: number
creditTop: number
bodyFont: string
bodyLineHeight: number
bodyLines: ProjectedBodyLine[]
}
type BandObstacle =
| {
kind: 'polygon'
points: Point[]
horizontalPadding: number
verticalPadding: number
}
| {
kind: 'rects'
rects: Rect[]
horizontalPadding: number
verticalPadding: number
}
type PageLayout = {
isNarrow: boolean
gutter: number
pageWidth: number
pageHeight: number
centerGap: number
columnWidth: number
headlineRegion: Rect
headlineFont: string
headlineLineHeight: number
creditGap: number
copyGap: number
openaiRect: Rect
claudeRect: Rect
}
type LogoHits = { openai: Point[]; claude: Point[] }
type WrapHulls = {
openaiLayout: Point[]
claudeLayout: Point[]
openaiHit: Point[]
claudeHit: Point[]
}
const stageNode = document.getElementById('stage')
if (!(stageNode instanceof HTMLDivElement)) throw new Error('#stage not found')
const stage = stageNode
const pageNode = document.querySelector('.page')
if (!(pageNode instanceof HTMLElement)) throw new Error('.page not found')
type DomCache = {
page: HTMLElement // cache lifetime: page
headline: HTMLHeadingElement // cache lifetime: page
credit: HTMLParagraphElement // cache lifetime: page
openaiLogo: HTMLImageElement // cache lifetime: page
claudeLogo: HTMLImageElement // cache lifetime: page
headlineLines: HTMLSpanElement[] // cache lifetime: headline line count
bodyLines: HTMLSpanElement[] // cache lifetime: visible line count
}
const preparedByKey = new Map()
const scheduled = { value: false }
const events: { mousemove: MouseEvent | null; click: MouseEvent | null; blur: boolean } = {
mousemove: null,
click: null,
blur: false,
}
const pointer = { x: -Infinity, y: -Infinity }
let currentLogoHits!: LogoHits
let hoveredLogo: LogoKind | null = null
let committedTextProjection: TextProjection | null = null
const logoAnimations: { openai: LogoAnimationState; claude: LogoAnimationState } = {
openai: { angle: 0, spin: null },
claude: { angle: 0, spin: null },
}
const domCache: DomCache = {
page: pageNode,
headline: createHeadline(),
credit: createCredit(),
openaiLogo: createLogo('logo logo--openai', 'OpenAI symbol', OPENAI_LOGO_SRC),
claudeLogo: createLogo('logo logo--claude', 'Claude symbol', CLAUDE_LOGO_SRC),
headlineLines: [],
bodyLines: [],
}
function createHeadline(): HTMLHeadingElement {
const element = document.createElement('h1')
element.className = 'headline'
return element
}
function createCredit(): HTMLParagraphElement {
const element = document.createElement('p')
element.className = 'credit'
element.textContent = CREDIT_TEXT
return element
}
function createLogo(className: string, alt: string, src: string): HTMLImageElement {
const element = document.createElement('img')
element.className = className
element.alt = alt
element.src = src
element.draggable = false
return element
}
function mountStaticNodes(): void {
stage.append(
domCache.headline,
domCache.credit,
domCache.openaiLogo,
domCache.claudeLogo,
)
}
const [, openaiLayout, claudeLayout, openaiHit, claudeHit] = await Promise.all([
document.fonts.ready,
getWrapHull(OPENAI_LOGO_SRC, { smoothRadius: 6, mode: 'mean' }),
getWrapHull(CLAUDE_LOGO_SRC, { smoothRadius: 6, mode: 'mean' }),
getWrapHull(OPENAI_LOGO_SRC, { smoothRadius: 3, mode: 'mean' }),
getWrapHull(CLAUDE_LOGO_SRC, { smoothRadius: 5, mode: 'mean' }),
])
const wrapHulls: WrapHulls = { openaiLayout, claudeLayout, openaiHit, claudeHit }
const preparedBody = getPrepared(BODY_COPY, BODY_FONT)
const preparedCredit = getPrepared(CREDIT_TEXT, CREDIT_FONT)
const creditWidth = Math.ceil(getPreparedSingleLineWidth(preparedCredit))
function getTypography(): { font: string, lineHeight: number } {
return { font: BODY_FONT, lineHeight: BODY_LINE_HEIGHT }
}
function getPrepared(text: string, font: string): PreparedTextWithSegments {
const key = `${font}::${text}`
const cached = preparedByKey.get(key)
if (cached !== undefined) return cached
const prepared = prepareWithSegments(text, font)
preparedByKey.set(key, prepared)
return prepared
}
function getPreparedSingleLineWidth(prepared: PreparedTextWithSegments): number {
let width = 0
walkLineRanges(prepared, 100_000, line => {
width = line.width
})
return width
}
function headlineBreaksInsideWord(prepared: PreparedTextWithSegments, maxWidth: number): boolean {
let breaksInsideWord = false
walkLineRanges(prepared, maxWidth, line => {
if (line.end.graphemeIndex !== 0) breaksInsideWord = true
})
return breaksInsideWord
}
function getObstacleIntervals(obstacle: BandObstacle, bandTop: number, bandBottom: number): Interval[] {
switch (obstacle.kind) {
case 'polygon': {
const interval = getPolygonIntervalForBand(
obstacle.points,
bandTop,
bandBottom,
obstacle.horizontalPadding,
obstacle.verticalPadding,
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "sed -n '261,520p' pages/demos/dynamic-layout.ts"
Chunk ID: 2dc162
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 2075
Output:
)
return interval === null ? [] : [interval]
}
case 'rects':
return getRectIntervalsForBand(
obstacle.rects,
bandTop,
bandBottom,
obstacle.horizontalPadding,
obstacle.verticalPadding,
)
}
}
function layoutColumn(
prepared: PreparedTextWithSegments,
startCursor: LayoutCursor,
region: Rect,
lineHeight: number,
obstacles: BandObstacle[],
side: 'left' | 'right',
): { lines: PositionedLine[], cursor: LayoutCursor } {
let cursor: LayoutCursor = startCursor
let lineTop = region.y
const lines: PositionedLine[] = []
while (true) {
if (lineTop + lineHeight > region.y + region.height) break
const bandTop = lineTop
const bandBottom = lineTop + lineHeight
const blocked: Interval[] = []
for (let obstacleIndex = 0; obstacleIndex < obstacles.length; obstacleIndex++) {
const obstacle = obstacles[obstacleIndex]!
const intervals = getObstacleIntervals(obstacle, bandTop, bandBottom)
for (let intervalIndex = 0; intervalIndex < intervals.length; intervalIndex++) {
blocked.push(intervals[intervalIndex]!)
}
}
const slots = carveTextLineSlots(
{ left: region.x, right: region.x + region.width },
blocked,
)
if (slots.length === 0) {
lineTop += lineHeight
continue
}
let slot = slots[0]!
for (let slotIndex = 1; slotIndex < slots.length; slotIndex++) {
const candidate = slots[slotIndex]!
const bestWidth = slot.right - slot.left
const candidateWidth = candidate.right - candidate.left
if (candidateWidth > bestWidth) {
slot = candidate
continue
}
if (candidateWidth < bestWidth) continue
if (side === 'left') {
if (candidate.left > slot.left) slot = candidate
continue
}
if (candidate.left < slot.left) slot = candidate
}
const width = slot.right - slot.left
const line = layoutNextLine(prepared, cursor, width)
if (line === null) break
lines.push({
x: Math.round(slot.left),
y: Math.round(lineTop),
width: line.width,
text: line.text,
})
cursor = line.end
lineTop += lineHeight
}
return { lines, cursor }
}
function syncPool(pool: T[], length: number, create: () => T, parent: HTMLElement = stage): void {
while (pool.length < length) {
const element = create()
pool.push(element)
parent.appendChild(element)
}
while (pool.length > length) {
const element = pool.pop()!
element.remove()
}
}
function projectHeadlineLines(lines: PositionedLine[], font: string, lineHeight: number): void {
syncPool(domCache.headlineLines, lines.length, () => {
const element = document.createElement('span')
element.className = 'headline-line'
return element
}, domCache.headline)
for (let index = 0; index < lines.length; index++) {
const line = lines[index]!
const element = domCache.headlineLines[index]!
element.textContent = line.text
element.style.left = `${line.x}px`
element.style.top = `${line.y}px`
element.style.font = font
element.style.lineHeight = `${lineHeight}px`
}
}
function projectChromeLayout(layout: PageLayout, contentHeight: number): void {
domCache.page.className = layout.isNarrow ? 'page page--mobile' : 'page'
stage.style.height = `${contentHeight}px`
domCache.openaiLogo.style.left = `${layout.openaiRect.x}px`
domCache.openaiLogo.style.top = `${layout.openaiRect.y}px`
domCache.openaiLogo.style.width = `${layout.openaiRect.width}px`
domCache.openaiLogo.style.height = `${layout.openaiRect.height}px`
domCache.openaiLogo.style.transform = `rotate(${logoAnimations.openai.angle}rad)`
domCache.claudeLogo.style.left = `${layout.claudeRect.x}px`
domCache.claudeLogo.style.top = `${layout.claudeRect.y}px`
domCache.claudeLogo.style.width = `${layout.claudeRect.width}px`
domCache.claudeLogo.style.height = `${layout.claudeRect.height}px`
domCache.claudeLogo.style.transform = `rotate(${logoAnimations.claude.angle}rad)`
}
function positionedLinesEqual(a: PositionedLine[], b: PositionedLine[]): boolean {
if (a.length !== b.length) return false
for (let index = 0; index < a.length; index++) {
const left = a[index]!
const right = b[index]!
if (
left.x !== right.x ||
left.y !== right.y ||
left.width !== right.width ||
left.text !== right.text
) {
return false
}
}
return true
}
function projectedBodyLinesEqual(a: ProjectedBodyLine[], b: ProjectedBodyLine[]): boolean {
if (a.length !== b.length) return false
for (let index = 0; index < a.length; index++) {
const left = a[index]!
const right = b[index]!
if (
left.className !== right.className ||
left.x !== right.x ||
left.y !== right.y ||
left.width !== right.width ||
left.text !== right.text
) {
return false
}
}
return true
}
function textProjectionEqual(a: TextProjection | null, b: TextProjection): boolean {
return a !== null &&
a.pageWidth === b.pageWidth &&
a.pageHeight === b.pageHeight &&
a.headlineFont === b.headlineFont &&
a.headlineLineHeight === b.headlineLineHeight &&
a.creditLeft === b.creditLeft &&
a.creditTop === b.creditTop &&
a.bodyFont === b.bodyFont &&
a.bodyLineHeight === b.bodyLineHeight &&
positionedLinesEqual(a.headlineLines, b.headlineLines) &&
projectedBodyLinesEqual(a.bodyLines, b.bodyLines)
}
function projectTextProjection(projection: TextProjection): void {
domCache.headline.style.left = '0px'
domCache.headline.style.top = '0px'
domCache.headline.style.width = `${projection.pageWidth}px`
domCache.headline.style.height = `${projection.pageHeight}px`
domCache.headline.style.font = projection.headlineFont
domCache.headline.style.lineHeight = `${projection.headlineLineHeight}px`
domCache.headline.style.letterSpacing = '0px'
projectHeadlineLines(projection.headlineLines, projection.headlineFont, projection.headlineLineHeight)
domCache.credit.style.left = `${projection.creditLeft}px`
domCache.credit.style.top = `${projection.creditTop}px`
domCache.credit.style.width = 'auto'
domCache.credit.style.font = CREDIT_FONT
domCache.credit.style.lineHeight = `${CREDIT_LINE_HEIGHT}px`
syncPool(domCache.bodyLines, projection.bodyLines.length, () => {
const element = document.createElement('span')
element.className = 'line'
return element
})
for (let index = 0; index < projection.bodyLines.length; index++) {
const line = projection.bodyLines[index]!
const element = domCache.bodyLines[index]!
element.className = line.className
element.textContent = line.text
element.style.left = `${line.x}px`
element.style.top = `${line.y}px`
element.style.font = projection.bodyFont
element.style.lineHeight = `${projection.bodyLineHeight}px`
}
}
function fitHeadlineFontSize(headlineWidth: number, pageWidth: number): number {
let low = Math.ceil(Math.max(22, pageWidth * 0.026))
let high = Math.floor(Math.min(94.4, Math.max(55.2, pageWidth * 0.055)))
let best = low
while (low <= high) {
const size = Math.floor((low + high) / 2)
const font = `700 ${size}px ${HEADLINE_FONT_FAMILY}`
const headlinePrepared = getPrepared(HEADLINE_TEXT, font)
if (!headlineBreaksInsideWord(headlinePrepared, headlineWidth)) {
best = size
low = size + 1
} else {
high = size - 1
}
}
return best
}
function easeSpin(t: number): number {
const oneMinusT = 1 - t
return 1 - oneMinusT * oneMinusT * oneMinusT
}
function getLogoAnimation(kind: LogoKind): LogoAnimationState {
switch (kind) {
case 'openai':
return logoAnimations.openai
case 'claude':
return logoAnimations.claude
}
}
function updateLogoSpin(logo: LogoAnimationState, now: number): boolean {
if (logo.spin === null) return false
const progress = Math.min(1, (now - logo.spin.start) / logo.spin.duration)
logo.angle = logo.spin.from + (logo.spin.to - logo.spin.from) * easeSpin(progress)
if (progress >= 1) {
logo.angle = logo.spin.to
logo.spin = null
return false
}
return true
}
function updateSpinState(now: number): boolean {
```
## Assistant
The demos matter less as “marketing” than as proofs of the abstraction boundary. They show that once you have deterministic line geometry plus resumable cursors, you can treat text like any other routed medium: pack it into masonry, hand it across columns, run it around polygons, compose it with inline chips, or feed it into a justification optimizer.
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "sed -n '1,260p' pages/demos/justification-comparison.model.ts",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "sed -n '261,520p' pages/demos/justification-comparison.model.ts",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "sed -n '1,220p' pages/demos/bubbles-shared.ts",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "sed -n '1,220p' pages/demos/variable-typographic-ascii.ts",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "sed -n '1,260p' pages/demos/justification-comparison.model.ts"
Chunk ID: 461a25
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 1891
Output:
import {
prepareWithSegments,
layoutNextLine,
type LayoutCursor,
type PreparedTextWithSegments,
} from '../../src/layout.ts'
import {
FONT,
HYPHEN_EXCEPTIONS,
LINE_HEIGHT,
PAD,
PARA_GAP,
PARAGRAPHS,
PREFIXES,
SUFFIXES,
} from './justification-comparison.data.ts'
const HUGE_BADNESS = 1e8
const SOFT_HYPHEN = '\u00AD'
const SHORT_LINE_RATIO = 0.6
const RIVER_THRESHOLD = 1.5
const INFEASIBLE_SPACE_RATIO = 0.4
const OVERFLOW_SPACE_RATIO = 0.2
const MIN_READABLE_SPACE_RATIO = 0.75
const TIGHT_SPACE_RATIO = 0.65
export type DemoControls = {
colWidth: number
showIndicators: boolean
}
export type DemoResources = {
basePreparedParagraphs: PreparedTextWithSegments[]
hyphenatedPreparedParagraphs: PreparedTextWithSegments[]
normalSpaceWidth: number
hyphenWidth: number
}
type TrailingMarker = 'none' | 'soft-hyphen'
type LineEnding = 'paragraph-end' | 'wrap'
type BreakCandidateKind = 'start' | 'space' | 'soft-hyphen' | 'end'
export type LineSegment =
| { kind: 'text'; text: string; width: number }
| { kind: 'space'; width: number }
export type MeasuredLine = {
segments: LineSegment[]
wordWidth: number
spaceCount: number
naturalWidth: number
maxWidth: number
ending: LineEnding
trailingMarker: TrailingMarker
}
export type LineSpacing =
| { kind: 'ragged' }
| { kind: 'overflow' }
| { kind: 'justified'; width: number; isRiver: boolean }
export type PositionedLine = MeasuredLine & {
y: number
spacing: LineSpacing
}
export type QualityMetrics = {
avgDeviation: number
maxDeviation: number
riverCount: number
lineCount: number
}
export type CanvasColumnFrame = {
colWidth: number
totalHeight: number
paragraphs: PositionedLine[][]
metrics: QualityMetrics
}
export type DemoFrame = {
controls: DemoControls
css: {
metrics: QualityMetrics
}
hyphen: CanvasColumnFrame
optimal: CanvasColumnFrame
}
export type RiverIndicator = {
red: number
green: number
blue: number
alpha: number
}
type BreakCandidate = {
segIndex: number
kind: BreakCandidateKind
}
type LineStats = {
wordWidth: number
spaceCount: number
naturalWidth: number
trailingMarker: TrailingMarker
}
export function createDemoResources(): DemoResources {
const measureCanvas = document.createElement('canvas')
const measureCtx = measureCanvas.getContext('2d')
if (measureCtx === null) throw new Error('2D canvas context is required for the demo')
measureCtx.font = FONT
return {
basePreparedParagraphs: PARAGRAPHS.map(paragraph => prepareWithSegments(paragraph, FONT)),
hyphenatedPreparedParagraphs: PARAGRAPHS.map(paragraph => prepareWithSegments(hyphenateParagraphText(paragraph), FONT)),
normalSpaceWidth: measureCtx.measureText(' ').width,
hyphenWidth: measureCtx.measureText('-').width,
}
}
export function buildDemoFrame(resources: DemoResources, controls: DemoControls): DemoFrame {
const innerWidth = controls.colWidth - PAD * 2
const cssParagraphs = layoutParagraphsGreedy(resources.basePreparedParagraphs, innerWidth, resources.hyphenWidth)
const hyphenParagraphs = layoutParagraphsGreedy(resources.hyphenatedPreparedParagraphs, innerWidth, resources.hyphenWidth)
const optimalParagraphs = layoutParagraphsOptimal(resources.hyphenatedPreparedParagraphs, innerWidth, resources)
return {
controls,
css: {
metrics: computeMetrics(cssParagraphs, resources.normalSpaceWidth),
},
hyphen: buildCanvasColumnFrame(controls.colWidth, hyphenParagraphs, resources.normalSpaceWidth),
optimal: buildCanvasColumnFrame(controls.colWidth, optimalParagraphs, resources.normalSpaceWidth),
}
}
export function getRiverIndicator(spaceWidth: number, normalSpaceWidth: number): RiverIndicator | null {
if (spaceWidth <= normalSpaceWidth * RIVER_THRESHOLD) return null
const intensity = Math.min(1, (spaceWidth / normalSpaceWidth - RIVER_THRESHOLD) / RIVER_THRESHOLD)
return {
red: Math.round(220 + intensity * 35),
green: Math.round(180 - intensity * 80),
blue: Math.round(180 - intensity * 80),
alpha: 0.25 + intensity * 0.35,
}
}
function hyphenateParagraphText(paragraph: string): string {
const words = paragraph.split(/(\s+)/)
let hyphenated = ''
for (let index = 0; index < words.length; index++) {
const token = words[index]!
if (/^\s+$/.test(token)) {
hyphenated += token
continue
}
const parts = hyphenateWord(token)
hyphenated += parts.length <= 1 ? token : parts.join(SOFT_HYPHEN)
}
return hyphenated
}
function hyphenateWord(word: string): string[] {
const lower = word.toLowerCase().replace(/[.,;:!?"'—–-]/g, '')
if (lower.length < 5) return [word]
const exactMatch = HYPHEN_EXCEPTIONS[lower]
if (exactMatch !== undefined) {
const parts: string[] = []
let position = 0
for (let index = 0; index < exactMatch.length; index++) {
const part = exactMatch[index]!
parts.push(word.slice(position, position + part.length))
position += part.length
}
if (position < word.length) {
parts[parts.length - 1] += word.slice(position)
}
return parts
}
for (let index = 0; index < PREFIXES.length; index++) {
const prefix = PREFIXES[index]!
if (lower.startsWith(prefix) && lower.length - prefix.length >= 3) {
return [word.slice(0, prefix.length), word.slice(prefix.length)]
}
}
for (let index = 0; index < SUFFIXES.length; index++) {
const suffix = SUFFIXES[index]!
if (lower.endsWith(suffix) && lower.length - suffix.length >= 3) {
const cut = word.length - suffix.length
return [word.slice(0, cut), word.slice(cut)]
}
}
return [word]
}
function layoutParagraphsGreedy(
preparedParagraphs: PreparedTextWithSegments[],
maxWidth: number,
hyphenWidth: number,
): MeasuredLine[][] {
const paragraphs: MeasuredLine[][] = []
for (let index = 0; index < preparedParagraphs.length; index++) {
paragraphs.push(layoutParagraphGreedy(preparedParagraphs[index]!, maxWidth, hyphenWidth))
}
return paragraphs
}
function layoutParagraphGreedy(
prepared: PreparedTextWithSegments,
maxWidth: number,
hyphenWidth: number,
): MeasuredLine[] {
const lines: MeasuredLine[] = []
let cursor: LayoutCursor = { segmentIndex: 0, graphemeIndex: 0 }
while (true) {
const line = layoutNextLine(prepared, cursor, maxWidth)
if (line === null) break
lines.push(buildMeasuredLineFromLayoutResult(prepared, line.start, line.end, maxWidth, hyphenWidth))
cursor = line.end
}
return lines
}
function buildMeasuredLineFromLayoutResult(
prepared: PreparedTextWithSegments,
start: LayoutCursor,
end: LayoutCursor,
maxWidth: number,
hyphenWidth: number,
): MeasuredLine {
const ending: LineEnding = end.segmentIndex >= prepared.segments.length ? 'paragraph-end' : 'wrap'
let trailingMarker: TrailingMarker = 'none'
const segments: LineSegment[] = []
for (let segIndex = start.segmentIndex; segIndex < end.segmentIndex; segIndex++) {
const text = prepared.segments[segIndex]!
if (text === SOFT_HYPHEN) {
if (segIndex === end.segmentIndex - 1) trailingMarker = 'soft-hyphen'
continue
}
segments.push(toLineSegment(text, prepared.widths[segIndex]!))
}
if (trailingMarker === 'none' && end.segmentIndex < prepared.segments.length) {
if (prepared.segments[end.segmentIndex] === SOFT_HYPHEN) trailingMarker = 'soft-hyphen'
}
if (trailingMarker === 'soft-hyphen' && ending === 'wrap') {
segments.push({ kind: 'text', text: '-', width: hyphenWidth })
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "sed -n '261,520p' pages/demos/justification-comparison.model.ts"
Chunk ID: 9fe571
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 1920
Output:
trimTrailingSpaces(segments)
return finalizeMeasuredLine(segments, maxWidth, ending, trailingMarker)
}
function layoutParagraphsOptimal(
preparedParagraphs: PreparedTextWithSegments[],
maxWidth: number,
resources: DemoResources,
): MeasuredLine[][] {
const paragraphs: MeasuredLine[][] = []
for (let index = 0; index < preparedParagraphs.length; index++) {
paragraphs.push(layoutParagraphOptimal(preparedParagraphs[index]!, maxWidth, resources))
}
return paragraphs
}
function layoutParagraphOptimal(
prepared: PreparedTextWithSegments,
maxWidth: number,
resources: DemoResources,
): MeasuredLine[] {
const segments = prepared.segments
const widths = prepared.widths
const segmentCount = segments.length
if (segmentCount === 0) return []
const breakCandidates: BreakCandidate[] = [{ segIndex: 0, kind: 'start' }]
for (let segIndex = 0; segIndex < segmentCount; segIndex++) {
const text = segments[segIndex]!
if (text === SOFT_HYPHEN) {
if (segIndex + 1 < segmentCount) breakCandidates.push({ segIndex: segIndex + 1, kind: 'soft-hyphen' })
continue
}
if (isSpaceText(text) && segIndex + 1 < segmentCount) {
breakCandidates.push({ segIndex: segIndex + 1, kind: 'space' })
}
}
breakCandidates.push({ segIndex: segmentCount, kind: 'end' })
const candidateCount = breakCandidates.length
const dp: number[] = new Array(candidateCount).fill(Infinity)
const previous: number[] = new Array(candidateCount).fill(-1)
dp[0] = 0
for (let toCandidate = 1; toCandidate < candidateCount; toCandidate++) {
const isLastLine = breakCandidates[toCandidate]!.kind === 'end'
for (let fromCandidate = toCandidate - 1; fromCandidate >= 0; fromCandidate--) {
if (dp[fromCandidate] === Infinity) continue
const lineStats = getLineStatsFromBreakCandidates(
segments,
widths,
breakCandidates,
fromCandidate,
toCandidate,
resources.hyphenWidth,
resources.normalSpaceWidth,
)
if (lineStats.naturalWidth > maxWidth * 2) break
const totalBadness = dp[fromCandidate]! + lineBadness(lineStats, maxWidth, resources.normalSpaceWidth, isLastLine)
if (totalBadness < dp[toCandidate]!) {
dp[toCandidate] = totalBadness
previous[toCandidate] = fromCandidate
}
}
}
const breakIndices: number[] = []
let current = candidateCount - 1
while (current > 0) {
if (previous[current] === -1) {
current--
continue
}
breakIndices.push(current)
current = previous[current]!
}
breakIndices.reverse()
const lines: MeasuredLine[] = []
let fromCandidate = 0
for (let index = 0; index < breakIndices.length; index++) {
const toCandidate = breakIndices[index]!
lines.push(buildMeasuredLineFromCandidateRange(prepared, breakCandidates, fromCandidate, toCandidate, maxWidth, resources.hyphenWidth))
fromCandidate = toCandidate
}
return lines
}
function getLineStatsFromBreakCandidates(
segments: readonly string[],
widths: readonly number[],
breakCandidates: readonly BreakCandidate[],
fromCandidate: number,
toCandidate: number,
hyphenWidth: number,
normalSpaceWidth: number,
): LineStats {
const from = breakCandidates[fromCandidate]!.segIndex
const to = breakCandidates[toCandidate]!.segIndex
const trailingMarker: TrailingMarker = breakCandidates[toCandidate]!.kind === 'soft-hyphen'
? 'soft-hyphen'
: 'none'
let wordWidth = 0
let spaceCount = 0
for (let segIndex = from; segIndex < to; segIndex++) {
const text = segments[segIndex]!
if (text === SOFT_HYPHEN) continue
if (isSpaceText(text)) {
spaceCount++
continue
}
wordWidth += widths[segIndex]!
}
if (to > from && isSpaceText(segments[to - 1]!)) {
spaceCount--
}
if (trailingMarker === 'soft-hyphen') {
wordWidth += hyphenWidth
}
return {
wordWidth,
spaceCount,
naturalWidth: wordWidth + spaceCount * normalSpaceWidth,
trailingMarker,
}
}
function lineBadness(
lineStats: LineStats,
maxWidth: number,
normalSpaceWidth: number,
isLastLine: boolean,
): number {
if (isLastLine) {
if (lineStats.wordWidth > maxWidth) return HUGE_BADNESS
return 0
}
if (lineStats.spaceCount <= 0) {
const slack = maxWidth - lineStats.wordWidth
if (slack < 0) return HUGE_BADNESS
return slack * slack * 10
}
const justifiedSpace = (maxWidth - lineStats.wordWidth) / lineStats.spaceCount
if (justifiedSpace < 0) return HUGE_BADNESS
if (justifiedSpace < normalSpaceWidth * INFEASIBLE_SPACE_RATIO) return HUGE_BADNESS
const ratio = (justifiedSpace - normalSpaceWidth) / normalSpaceWidth
const absRatio = Math.abs(ratio)
const badness = absRatio * absRatio * absRatio * 1000
const riverExcess = justifiedSpace / normalSpaceWidth - RIVER_THRESHOLD
const riverPenalty = riverExcess > 0
? 5000 + riverExcess * riverExcess * 10000
: 0
const tightThreshold = normalSpaceWidth * TIGHT_SPACE_RATIO
const tightPenalty = justifiedSpace < tightThreshold
? 3000 + (tightThreshold - justifiedSpace) * (tightThreshold - justifiedSpace) * 10000
: 0
const hyphenPenalty = lineStats.trailingMarker === 'soft-hyphen' ? 50 : 0
return badness + riverPenalty + tightPenalty + hyphenPenalty
}
function buildMeasuredLineFromCandidateRange(
prepared: PreparedTextWithSegments,
breakCandidates: readonly BreakCandidate[],
fromCandidate: number,
toCandidate: number,
maxWidth: number,
hyphenWidth: number,
): MeasuredLine {
const from = breakCandidates[fromCandidate]!.segIndex
const to = breakCandidates[toCandidate]!.segIndex
const ending: LineEnding = breakCandidates[toCandidate]!.kind === 'end' ? 'paragraph-end' : 'wrap'
const trailingMarker: TrailingMarker = breakCandidates[toCandidate]!.kind === 'soft-hyphen'
? 'soft-hyphen'
: 'none'
const segments: LineSegment[] = []
for (let segIndex = from; segIndex < to; segIndex++) {
const text = prepared.segments[segIndex]!
if (text === SOFT_HYPHEN) continue
segments.push(toLineSegment(text, prepared.widths[segIndex]!))
}
if (trailingMarker === 'soft-hyphen' && ending === 'wrap') {
segments.push({ kind: 'text', text: '-', width: hyphenWidth })
}
trimTrailingSpaces(segments)
return finalizeMeasuredLine(segments, maxWidth, ending, trailingMarker)
}
function toLineSegment(text: string, width: number): LineSegment {
if (isSpaceText(text)) return { kind: 'space', width }
return { kind: 'text', text, width }
}
function trimTrailingSpaces(segments: LineSegment[]): void {
while (segments.length > 0 && segments[segments.length - 1]!.kind === 'space') {
segments.pop()
}
}
function finalizeMeasuredLine(
segments: LineSegment[],
maxWidth: number,
ending: LineEnding,
trailingMarker: TrailingMarker,
): MeasuredLine {
let wordWidth = 0
let spaceCount = 0
let naturalWidth = 0
for (let index = 0; index < segments.length; index++) {
const segment = segments[index]!
naturalWidth += segment.width
if (segment.kind === 'space') {
spaceCount++
continue
}
wordWidth += segment.width
}
return {
segments,
wordWidth,
spaceCount,
naturalWidth,
maxWidth,
ending,
trailingMarker,
}
}
function computeMetrics(
paragraphs: MeasuredLine[][],
normalSpaceWidth: number,
): QualityMetrics {
let totalDeviation = 0
let maxDeviation = 0
let deviationCount = 0
let riverCount = 0
let lineCount = 0
for (let paragraphIndex = 0; paragraphIndex < paragraphs.length; paragraphIndex++) {
const paragraph = paragraphs[paragraphIndex]!
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "sed -n '1,220p' pages/demos/bubbles-shared.ts"
Chunk ID: 0e94f4
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 847
Output:
import { layout, prepareWithSegments, walkLineRanges, type PreparedTextWithSegments } from '../../src/layout.ts'
export type WrapMetrics = {
lineCount: number
height: number
maxLineWidth: number
}
export type PreparedBubble = {
prepared: PreparedTextWithSegments
}
export type BubbleRenderWidths = {
cssWidth: number
tightWidth: number
}
export type BubbleRenderState = {
chatWidth: number
bubbleMaxWidth: number
totalWastedPixels: number
widths: BubbleRenderWidths[]
}
export const FONT = '15px "Helvetica Neue", Helvetica, Arial, sans-serif'
export const LINE_HEIGHT = 20
export const PADDING_H = 12
export const PADDING_V = 8
export const BUBBLE_MAX_RATIO = 0.8
export const PAGE_MAX_WIDTH = 1080
export const DESKTOP_PAGE_MARGIN = 32
export const MOBILE_PAGE_MARGIN = 20
export const GRID_GAP = 16
export const PANEL_PADDING_X = 36
export function prepareBubbleTexts(texts: string[]): PreparedBubble[] {
return texts.map(text => ({
prepared: prepareWithSegments(text, FONT),
}))
}
export function getMaxChatWidth(minWidth: number, viewportWidth: number): number {
const pageWidth = Math.min(PAGE_MAX_WIDTH, viewportWidth - (viewportWidth <= 760 ? MOBILE_PAGE_MARGIN : DESKTOP_PAGE_MARGIN))
const columnWidth = viewportWidth <= 760 ? pageWidth : (pageWidth - GRID_GAP) / 2
const panelContentWidth = Math.max(1, Math.floor(columnWidth - PANEL_PADDING_X))
return Math.max(minWidth, panelContentWidth)
}
export function collectWrapMetrics(prepared: PreparedTextWithSegments, maxWidth: number): WrapMetrics {
let maxLineWidth = 0
const lineCount = walkLineRanges(prepared, maxWidth, line => {
if (line.width > maxLineWidth) maxLineWidth = line.width
})
return {
lineCount,
height: lineCount * LINE_HEIGHT,
maxLineWidth,
}
}
export function findTightWrapMetrics(prepared: PreparedTextWithSegments, maxWidth: number): WrapMetrics {
const initial = collectWrapMetrics(prepared, maxWidth)
let lo = 1
let hi = Math.max(1, Math.ceil(maxWidth))
while (lo < hi) {
const mid = Math.floor((lo + hi) / 2)
const midLineCount = layout(prepared, mid, LINE_HEIGHT).lineCount
if (midLineCount <= initial.lineCount) {
hi = mid
} else {
lo = mid + 1
}
}
return collectWrapMetrics(prepared, lo)
}
export function computeBubbleRender(preparedBubbles: PreparedBubble[], chatWidth: number): BubbleRenderState {
const bubbleMaxWidth = Math.floor(chatWidth * BUBBLE_MAX_RATIO)
const contentMaxWidth = bubbleMaxWidth - PADDING_H * 2
let totalWastedPixels = 0
const widths: BubbleRenderWidths[] = []
for (let index = 0; index < preparedBubbles.length; index++) {
const bubble = preparedBubbles[index]!
const cssMetrics = collectWrapMetrics(bubble.prepared, contentMaxWidth)
const tightMetrics = findTightWrapMetrics(bubble.prepared, contentMaxWidth)
const cssWidth = Math.ceil(cssMetrics.maxLineWidth) + PADDING_H * 2
const tightWidth = Math.ceil(tightMetrics.maxLineWidth) + PADDING_H * 2
const cssHeight = cssMetrics.height + PADDING_V * 2
totalWastedPixels += Math.max(0, cssWidth - tightWidth) * cssHeight
widths.push({ cssWidth, tightWidth })
}
return {
chatWidth,
bubbleMaxWidth,
totalWastedPixels,
widths,
}
}
export function formatPixelCount(value: number): string {
return `${Math.round(value).toLocaleString()}`
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "sed -n '1,220p' pages/demos/variable-typographic-ascii.ts"
Chunk ID: cf7fb9
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 1803
Output:
import { prepareWithSegments } from '../../src/layout.ts'
const COLS = 50
const ROWS = 28
const FONT_SIZE = 14
const LINE_HEIGHT = 16
const TARGET_ROW_W = 440
const PROP_FAMILY = 'Georgia, Palatino, "Times New Roman", serif'
const FIELD_OVERSAMPLE = 2
const FIELD_COLS = COLS * FIELD_OVERSAMPLE
const FIELD_ROWS = ROWS * FIELD_OVERSAMPLE
const CANVAS_W = 220
const CANVAS_H = Math.round(CANVAS_W * ((ROWS * LINE_HEIGHT) / TARGET_ROW_W))
const FIELD_SCALE_X = FIELD_COLS / CANVAS_W
const FIELD_SCALE_Y = FIELD_ROWS / CANVAS_H
const PARTICLE_N = 120
const SPRITE_R = 14
const ATTRACTOR_R = 12
const LARGE_ATTRACTOR_R = 30
const ATTRACTOR_FORCE_1 = 0.22
const ATTRACTOR_FORCE_2 = 0.05
const FIELD_DECAY = 0.82
const CHARSET = ' .,:;!+-=*#@%&abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
const WEIGHTS = [300, 500, 800] as const
const STYLES = ['normal', 'italic'] as const
type FontStyleVariant = typeof STYLES[number]
type PaletteEntry = {
char: string
weight: number
style: FontStyleVariant
font: string
width: number
brightness: number
}
type BrightnessEntry = {
monoChar: string
propHtml: string
}
type Particle = {
x: number
y: number
vx: number
vy: number
}
type FieldStamp = {
radiusX: number
radiusY: number
sizeX: number
sizeY: number
values: Float32Array
}
type RowNodes = {
monoNode: HTMLDivElement
propNode: HTMLDivElement
}
function getRequiredDiv(id: string): HTMLDivElement {
const element = document.getElementById(id)
if (!(element instanceof HTMLDivElement)) throw new Error(`#${id} not found`)
return element
}
const brightnessCanvas = document.createElement('canvas')
brightnessCanvas.width = 28
brightnessCanvas.height = 28
const brightnessContext = brightnessCanvas.getContext('2d', { willReadFrequently: true })
if (brightnessContext === null) throw new Error('brightness context not available')
const bCtx = brightnessContext
function estimateBrightness(ch: string, font: string): number {
const size = 28
bCtx.clearRect(0, 0, size, size)
bCtx.font = font
bCtx.fillStyle = '#fff'
bCtx.textBaseline = 'middle'
bCtx.fillText(ch, 1, size / 2)
const data = bCtx.getImageData(0, 0, size, size).data
let sum = 0
for (let index = 3; index < data.length; index += 4) sum += data[index]!
return sum / (255 * size * size)
}
function measureWidth(ch: string, font: string): number {
const prepared = prepareWithSegments(ch, font)
return prepared.widths.length > 0 ? prepared.widths[0]! : 0
}
const palette: PaletteEntry[] = []
for (const style of STYLES) {
for (const weight of WEIGHTS) {
const font = `${style === 'italic' ? 'italic ' : ''}${weight} ${FONT_SIZE}px ${PROP_FAMILY}`
for (const ch of CHARSET) {
if (ch === ' ') continue
const width = measureWidth(ch, font)
if (width <= 0) continue
const brightness = estimateBrightness(ch, font)
palette.push({ char: ch, weight, style, font, width, brightness })
}
}
}
const maxBrightness = Math.max(...palette.map(entry => entry.brightness))
if (maxBrightness > 0) {
for (let index = 0; index < palette.length; index++) {
palette[index]!.brightness /= maxBrightness
}
}
palette.sort((a, b) => a.brightness - b.brightness)
const targetCellW = TARGET_ROW_W / COLS
function findBest(targetBrightness: number): PaletteEntry {
let lo = 0
let hi = palette.length - 1
while (lo < hi) {
const mid = (lo + hi) >> 1
if (palette[mid]!.brightness < targetBrightness) lo = mid + 1
else hi = mid
}
let bestScore = Infinity
let best = palette[lo]!
const start = Math.max(0, lo - 15)
const end = Math.min(palette.length, lo + 15)
for (let index = start; index < end; index++) {
const entry = palette[index]!
const brightnessError = Math.abs(entry.brightness - targetBrightness) * 2.5
const widthError = Math.abs(entry.width - targetCellW) / targetCellW
const score = brightnessError + widthError
if (score < bestScore) {
bestScore = score
best = entry
}
}
return best
}
const MONO_RAMP = ' .`-_:,;^=+/|)\\!?0oOQ#%@'
const brightnessLookup: BrightnessEntry[] = []
for (let brightnessByte = 0; brightnessByte < 256; brightnessByte++) {
const brightness = brightnessByte / 255
const monoChar = MONO_RAMP[Math.min(MONO_RAMP.length - 1, (brightness * MONO_RAMP.length) | 0)]!
if (brightness < 0.03) {
brightnessLookup.push({ monoChar, propHtml: ' ' })
continue
}
const match = findBest(brightness)
const alphaIndex = Math.max(1, Math.min(10, Math.round(brightness * 10)))
brightnessLookup.push({
monoChar,
propHtml: `${esc(match.char)}`,
})
}
const particles: Particle[] = []
for (let index = 0; index < PARTICLE_N; index++) {
const angle = Math.random() * Math.PI * 2
const radius = Math.random() * 40 + 20
particles.push({
x: CANVAS_W / 2 + Math.cos(angle) * radius,
y: CANVAS_H / 2 + Math.sin(angle) * radius,
vx: (Math.random() - 0.5) * 0.8,
vy: (Math.random() - 0.5) * 0.8,
})
}
const simulationCanvas = document.createElement('canvas')
simulationCanvas.width = CANVAS_W
simulationCanvas.height = CANVAS_H
simulationCanvas.className = 'source-canvas'
const simulationContext = simulationCanvas.getContext('2d', { willReadFrequently: true })
if (simulationContext === null) throw new Error('simulation context not available')
const sCtx = simulationContext
const brightnessField = new Float32Array(FIELD_COLS * FIELD_ROWS)
const spriteCache = new Map()
function getSpriteCanvas(radius: number): HTMLCanvasElement {
const cached = spriteCache.get(radius)
if (cached !== undefined) return cached
const canvas = document.createElement('canvas')
canvas.width = radius * 2
canvas.height = radius * 2
const context = canvas.getContext('2d')
if (context === null) throw new Error('sprite context not available')
const gradient = context.createRadialGradient(radius, radius, 0, radius, radius, radius)
gradient.addColorStop(0, 'rgba(255,255,255,0.45)')
gradient.addColorStop(0.35, 'rgba(255,255,255,0.15)')
gradient.addColorStop(1, 'rgba(255,255,255,0)')
context.fillStyle = gradient
context.fillRect(0, 0, radius * 2, radius * 2)
spriteCache.set(radius, canvas)
return canvas
}
function spriteAlphaAt(normalizedDistance: number): number {
if (normalizedDistance >= 1) return 0
if (normalizedDistance <= 0.35) return 0.45 + (0.15 - 0.45) * (normalizedDistance / 0.35)
return 0.15 * (1 - (normalizedDistance - 0.35) / 0.65)
}
function createFieldStamp(radiusPx: number): FieldStamp {
const fieldRadiusX = radiusPx * FIELD_SCALE_X
const fieldRadiusY = radiusPx * FIELD_SCALE_Y
const radiusX = Math.ceil(fieldRadiusX)
const radiusY = Math.ceil(fieldRadiusY)
const sizeX = radiusX * 2 + 1
const sizeY = radiusY * 2 + 1
const values = new Float32Array(sizeX * sizeY)
for (let y = -radiusY; y <= radiusY; y++) {
for (let x = -radiusX; x <= radiusX; x++) {
const normalizedDistance = Math.sqrt((x / fieldRadiusX) ** 2 + (y / fieldRadiusY) ** 2)
values[(y + radiusY) * sizeX + x + radiusX] = spriteAlphaAt(normalizedDistance)
```
## Assistant
I’m moving from static reading to validation. I want to confirm the behavioral model by running the permanent invariant suite and, if it’s cheap enough, one of the diagnostic harnesses so I’m not just inferring from source structure.
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "bun test src/layout.test.ts",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
exec_command failed for `/bin/zsh -lc 'bun test src/layout.test.ts'`: CreateProcess { message: "Rejected(\"Failed to create unified exec process: No such file or directory (os error 2)\")" }
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "git show f962f72:src/layout.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "git show 5ecce72:src/layout.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "git show fea1fa7:src/layout.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "git show f06fb75:src/line-break.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
exec_command failed for `/bin/zsh -lc "git show f962f72:src/layout.ts | sed -n '1,260p'"`: CreateProcess { message: "Rejected(\"Failed to create unified exec process: No such file or directory (os error 2)\")" }
```
## Assistant
**Result** (success):
```
exec_command failed for `/bin/zsh -lc "git show 5ecce72:src/layout.ts | sed -n '1,260p'"`: CreateProcess { message: "Rejected(\"Failed to create unified exec process: No such file or directory (os error 2)\")" }
```
## Assistant
**Result** (success):
```
exec_command failed for `/bin/zsh -lc "git show fea1fa7:src/layout.ts | sed -n '1,260p'"`: CreateProcess { message: "Rejected(\"Failed to create unified exec process: No such file or directory (os error 2)\")" }
```
## Assistant
**Result** (success):
```
exec_command failed for `/bin/zsh -lc "git show f06fb75:src/line-break.ts | sed -n '1,260p'"`: CreateProcess { message: "Rejected(\"Failed to create unified exec process: No such file or directory (os error 2)\")" }
```
## Assistant
The sandbox won’t run `bun`, so I can’t execute the shipped test harness directly. I’m still pulling older snapshots of the core files to see exactly what was added versus simplified over time; the history here is unusually revealing about the design intent.
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "git show --stat --oneline --no-patch f962f72",
"max_output_tokens": 4000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "git ls-tree --name-only -r f962f72 | head -n 40",
"max_output_tokens": 4000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "git ls-tree --name-only -r fea1fa7 | head -n 40",
"max_output_tokens": 4000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "git show --stat --oneline --no-patch fea1fa7",
"max_output_tokens": 4000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
exec_command failed for `/bin/zsh -lc 'git show --stat --oneline --no-patch f962f72'`: CreateProcess { message: "Rejected(\"Failed to create unified exec process: No such file or directory (os error 2)\")" }
```
## Assistant
**Result** (success):
```
exec_command failed for `/bin/zsh -lc 'git ls-tree --name-only -r f962f72 | head -n 40'`: CreateProcess { message: "Rejected(\"Failed to create unified exec process: No such file or directory (os error 2)\")" }
```
## Assistant
**Result** (success):
```
exec_command failed for `/bin/zsh -lc 'git ls-tree --name-only -r fea1fa7 | head -n 40'`: CreateProcess { message: "Rejected(\"Failed to create unified exec process: No such file or directory (os error 2)\")" }
```
## Assistant
**Result** (success):
```
exec_command failed for `/bin/zsh -lc 'git show --stat --oneline --no-patch fea1fa7'`: CreateProcess { message: "Rejected(\"Failed to create unified exec process: No such file or directory (os error 2)\")" }
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "ls",
"max_output_tokens": 2000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
exec_command failed for `/bin/zsh -lc ls`: CreateProcess { message: "Rejected(\"Failed to create unified exec process: No such file or directory (os error 2)\")" }
```
## Assistant
### Tool: read_thread_terminal
**Args:**
```json
{}
```
## Assistant
**Result** (success):
```
App terminal snapshot for this thread:
cwd: /Users/maxgeorgopoulos/Documents/blook/experiments
shell: zsh
```text
[1m[7m%[27m[1m[0m
[0m[27m[24m[Jmaxgeorgopoulos@Maxs-MacBook-Air experiments % [?2004h
```
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "ls pretext",
"max_output_tokens": 4000,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments",
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
exec_command failed for `/bin/zsh -lc 'ls pretext'`: CreateProcess { message: "Rejected(\"Failed to create unified exec process: No such file or directory (os error 2)\")" }
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "pwd",
"max_output_tokens": 2000,
"shell": "/bin/bash",
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments",
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
exec_command failed for `/bin/bash -lc pwd`: CreateProcess { message: "Rejected(\"Failed to create unified exec process: No such file or directory (os error 2)\")" }
```
## Assistant
I’ve hit a tooling glitch in the shell runner itself, so I’m finishing the deep read with the cloned source already in memory plus GitHub/spec sources. I have enough of the internals now to write the fundamental analysis rather than a repo summary.
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "pwd",
"max_output_tokens": 2000,
"tty": true,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments",
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc pwd
Chunk ID: 7f278e
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 6
Output:
/Users/maxgeorgopoulos
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "git show --stat --oneline --no-patch f962f72",
"max_output_tokens": 4000,
"tty": true,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "git show f962f72:src/layout.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"tty": true,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "git show 5ecce72:src/layout.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"tty": true,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "git show fea1fa7:src/layout.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"tty": true,
"workdir": "/Users/maxgeorgopoulos/Documents/blook/experiments/pretext",
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc 'git show --stat --oneline --no-patch f962f72'
Chunk ID: dfb768
Wall time: 0.0000 seconds
Process exited with code 128
Original token count: 18
Output:
fatal: not a git repository (or any of the parent directories): .git
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "git show f962f72:src/layout.ts | sed -n '1,260p'"
Chunk ID: 98552d
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 18
Output:
fatal: not a git repository (or any of the parent directories): .git
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "git show 5ecce72:src/layout.ts | sed -n '1,260p'"
Chunk ID: 89d314
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 18
Output:
fatal: not a git repository (or any of the parent directories): .git
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "git show fea1fa7:src/layout.ts | sed -n '1,260p'"
Chunk ID: 233e87
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 18
Output:
fatal: not a git repository (or any of the parent directories): .git
```
## Assistant
The shell runner only honors the right directory in TTY mode if I `cd` explicitly, so I’m doing that for the remaining history reads. I’m looking at the earliest `layout.ts`, the first major simplification pass, and the point where the rich API split landed.
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/blook/experiments/pretext && git show --stat --oneline --no-patch f962f72",
"max_output_tokens": 4000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/blook/experiments/pretext && git show f962f72:src/layout.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/blook/experiments/pretext && git show 5ecce72:src/layout.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/blook/experiments/pretext && git show fea1fa7:src/layout.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc 'cd /Users/maxgeorgopoulos/Documents/blook/experiments/pretext && git show --stat --oneline --no-patch f962f72'
Chunk ID: 1dcdfb
Wall time: 0.0000 seconds
Process exited with code 1
Original token count: 25
Output:
zsh:cd:1: no such file or directory: /Users/maxgeorgopoulos/Documents/blook/experiments/pretext
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/blook/experiments/pretext && git show f962f72:src/layout.ts | sed -n '1,260p'"
Chunk ID: 92be56
Wall time: 0.0000 seconds
Process exited with code 1
Original token count: 25
Output:
zsh:cd:1: no such file or directory: /Users/maxgeorgopoulos/Documents/blook/experiments/pretext
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/blook/experiments/pretext && git show 5ecce72:src/layout.ts | sed -n '1,260p'"
Chunk ID: 90a616
Wall time: 0.0000 seconds
Process exited with code 1
Original token count: 25
Output:
zsh:cd:1: no such file or directory: /Users/maxgeorgopoulos/Documents/blook/experiments/pretext
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/blook/experiments/pretext && git show fea1fa7:src/layout.ts | sed -n '1,260p'"
Chunk ID: 232b99
Wall time: 0.0000 seconds
Process exited with code 1
Original token count: 25
Output:
zsh:cd:1: no such file or directory: /Users/maxgeorgopoulos/Documents/blook/experiments/pretext
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "ls /Users/maxgeorgopoulos",
"max_output_tokens": 4000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc 'ls /Users/maxgeorgopoulos'
Chunk ID: 05e5ec
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 60
Output:
Applications Pictures
Calibre Library Public
Desktop Screen Studio Projects
Documents Soulseek Downloads
Downloads atkinson-hyperlegible-next-mono
Falcon blender
Library conductor
Movies imessage_export
Music
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "ls /Users/maxgeorgopoulos/Documents/blook/experiments",
"max_output_tokens": 4000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc 'ls /Users/maxgeorgopoulos/Documents/blook/experiments'
Chunk ID: 934444
Wall time: 0.0000 seconds
Process exited with code 1
Original token count: 21
Output:
ls: /Users/maxgeorgopoulos/Documents/blook/experiments: No such file or directory
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "find /Users/maxgeorgopoulos -maxdepth 4 -type d -name pretext 2>/dev/null | head -n 20",
"max_output_tokens": 4000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc 'find /Users/maxgeorgopoulos -maxdepth 4 -type d -name pretext 2>/dev/null | head -n 20'
Chunk ID: 35a835
Wall time: 1.0022 seconds
Process running with session ID 75582
Original token count: 0
Output:
```
## Assistant
### Tool: write_stdin
**Args:**
```json
{
"chars": "",
"max_output_tokens": 4000,
"session_id": 75582,
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc 'find /Users/maxgeorgopoulos -maxdepth 4 -type d -name pretext 2>/dev/null | head -n 20'
Chunk ID: e324ee
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 14
Output:
/Users/maxgeorgopoulos/Documents/experiments/pretext
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show --stat --oneline --no-patch f962f72",
"max_output_tokens": 4000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show f962f72:src/layout.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show 5ecce72:src/layout.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show fea1fa7:src/layout.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc 'cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show --stat --oneline --no-patch f962f72'
Chunk ID: fdc054
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 8
Output:
f962f72 Initial project setup
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show f962f72:src/layout.ts | sed -n '1,260p'"
Chunk ID: a426e5
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 2493
Output:
// Text measurement: Intl.Segmenter + canvas measureText + bidi.
// Two-phase: prepare() once per text, layout() is pure arithmetic on resize.
const canvas = typeof OffscreenCanvas !== 'undefined'
? new OffscreenCanvas(1, 1)
: document.createElement('canvas')
const ctx = canvas.getContext('2d')!
// --- Word width cache: font → Map ---
const wordCaches = new Map>()
function getWordCache(font: string): Map {
let cache = wordCaches.get(font)
if (!cache) {
cache = new Map()
wordCaches.set(font, cache)
}
return cache
}
function measureSegment(seg: string, cache: Map): number {
let w = cache.get(seg)
if (w === undefined) {
w = ctx.measureText(seg).width
cache.set(seg, w)
}
return w
}
function parseFontSize(font: string): number {
const m = font.match(/(\d+(?:\.\d+)?)\s*px/)
return m ? parseFloat(m[1]!) : 16
}
// --- CJK detection ---
function isCJK(s: string): boolean {
for (let i = 0; i < s.length; i++) {
const c = s.charCodeAt(i)
if ((c >= 0x4E00 && c <= 0x9FFF) || // CJK Unified
(c >= 0x3400 && c <= 0x4DBF) || // CJK Extension A
(c >= 0x3000 && c <= 0x303F) || // CJK Punctuation
(c >= 0x3040 && c <= 0x309F) || // Hiragana
(c >= 0x30A0 && c <= 0x30FF) || // Katakana
(c >= 0xAC00 && c <= 0xD7AF) || // Hangul
(c >= 0xFF00 && c <= 0xFFEF)) { // Fullwidth
return true
}
}
return false
}
// --- Bidi character classification (from Unicode/pdf.js) ---
type BidiType = 'L' | 'R' | 'AL' | 'AN' | 'EN' | 'ES' | 'ET' | 'CS' |
'ON' | 'BN' | 'B' | 'S' | 'WS' | 'NSM'
const baseTypes: BidiType[] = [
'BN','BN','BN','BN','BN','BN','BN','BN','BN','S','B','S','WS',
'B','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN',
'BN','BN','B','B','B','S','WS','ON','ON','ET','ET','ET','ON',
'ON','ON','ON','ON','ON','CS','ON','CS','ON','EN','EN','EN',
'EN','EN','EN','EN','EN','EN','EN','ON','ON','ON','ON','ON',
'ON','ON','L','L','L','L','L','L','L','L','L','L','L','L','L',
'L','L','L','L','L','L','L','L','L','L','L','L','L','ON','ON',
'ON','ON','ON','ON','L','L','L','L','L','L','L','L','L','L',
'L','L','L','L','L','L','L','L','L','L','L','L','L','L','L',
'L','ON','ON','ON','ON','BN','BN','BN','BN','BN','BN','B','BN',
'BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN',
'BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN',
'BN','CS','ON','ET','ET','ET','ET','ON','ON','ON','ON','L','ON',
'ON','ON','ON','ON','ET','ET','EN','EN','ON','L','ON','ON','ON',
'EN','L','ON','ON','ON','ON','ON','L','L','L','L','L','L','L',
'L','L','L','L','L','L','L','L','L','L','L','L','L','L','L',
'L','ON','L','L','L','L','L','L','L','L','L','L','L','L','L',
'L','L','L','L','L','L','L','L','L','L','L','L','L','L','L',
'L','L','L','ON','L','L','L','L','L','L','L','L'
]
const arabicTypes: BidiType[] = [
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'CS','AL','ON','ON','NSM','NSM','NSM','NSM','NSM','NSM','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','NSM','NSM','NSM','NSM','NSM','NSM','NSM',
'NSM','NSM','NSM','NSM','NSM','NSM','NSM','AL','AL','AL','AL',
'AL','AL','AL','AN','AN','AN','AN','AN','AN','AN','AN','AN',
'AN','ET','AN','AN','AL','AL','AL','NSM','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','NSM','NSM','NSM','NSM','NSM','NSM','NSM','NSM','NSM','NSM',
'NSM','NSM','NSM','NSM','NSM','NSM','NSM','NSM','NSM','ON','NSM',
'NSM','NSM','NSM','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL'
]
function classifyChar(charCode: number): BidiType {
if (charCode <= 0x00ff) return baseTypes[charCode]!
if (0x0590 <= charCode && charCode <= 0x05f4) return 'R'
if (0x0600 <= charCode && charCode <= 0x06ff) return arabicTypes[charCode & 0xff]!
if (0x0700 <= charCode && charCode <= 0x08AC) return 'AL'
return 'L'
}
function computeBidiLevels(str: string): Int8Array | null {
const len = str.length
if (len === 0) return null
const types: BidiType[] = new Array(len)
let numBidi = 0
for (let i = 0; i < len; i++) {
const t = classifyChar(str.charCodeAt(i))
if (t === 'R' || t === 'AL' || t === 'AN') numBidi++
types[i] = t
}
if (numBidi === 0) return null
const startLevel = (len / numBidi) < 0.3 ? 0 : 1
const levels = new Int8Array(len)
for (let i = 0; i < len; i++) levels[i] = startLevel
const e: BidiType = (startLevel & 1) ? 'R' : 'L'
const sor = e
// W1-W7
let lastType: BidiType = sor
for (let i = 0; i < len; i++) { if (types[i] === 'NSM') types[i] = lastType; else lastType = types[i]! }
lastType = sor
for (let i = 0; i < len; i++) { const t = types[i]!; if (t === 'EN') types[i] = lastType === 'AL' ? 'AN' : 'EN'; else if (t === 'R' || t === 'L' || t === 'AL') lastType = t }
for (let i = 0; i < len; i++) { if (types[i] === 'AL') types[i] = 'R' }
for (let i = 1; i < len - 1; i++) { if (types[i] === 'ES' && types[i-1] === 'EN' && types[i+1] === 'EN') types[i] = 'EN'; if (types[i] === 'CS' && (types[i-1] === 'EN' || types[i-1] === 'AN') && types[i+1] === types[i-1]) types[i] = types[i-1]! }
for (let i = 0; i < len; i++) { if (types[i] === 'EN') { let j; for (j = i-1; j >= 0 && types[j] === 'ET'; j--) types[j] = 'EN'; for (j = i+1; j < len && types[j] === 'ET'; j++) types[j] = 'EN' } }
for (let i = 0; i < len; i++) { const t = types[i]!; if (t === 'WS' || t === 'ES' || t === 'ET' || t === 'CS') types[i] = 'ON' }
lastType = sor
for (let i = 0; i < len; i++) { const t = types[i]!; if (t === 'EN') types[i] = lastType === 'L' ? 'L' : 'EN'; else if (t === 'R' || t === 'L') lastType = t }
// N1-N2
for (let i = 0; i < len; i++) {
if (types[i] === 'ON') {
let end = i + 1
while (end < len && types[end] === 'ON') end++
const before: BidiType = i > 0 ? types[i-1]! : sor
const after: BidiType = end < len ? types[end]! : sor
const bDir: BidiType = before !== 'L' ? 'R' : 'L'
const aDir: BidiType = after !== 'L' ? 'R' : 'L'
if (bDir === aDir) { for (let j = i; j < end; j++) types[j] = bDir }
i = end - 1
}
}
for (let i = 0; i < len; i++) { if (types[i] === 'ON') types[i] = e }
// I1-I2
for (let i = 0; i < len; i++) {
const t = types[i]!
if ((levels[i]! & 1) === 0) {
if (t === 'R') levels[i]!++
else if (t === 'AN' || t === 'EN') levels[i]! += 2
} else {
if (t === 'L' || t === 'AN' || t === 'EN') levels[i]!++
}
}
return levels
}
function reorderLine(segLevels: Int8Array, start: number, end: number): number[] | null {
let low = 127, high = 0
for (let i = start; i < end; i++) {
const lv = segLevels[i]!
if (lv < low) low = lv
if (lv > high) high = lv
}
if (high <= 0) return null
if (low % 2 === 0) low++
const indices = new Array(end - start)
for (let i = 0; i < indices.length; i++) indices[i] = start + i
while (high >= low) {
let i = 0
while (i < indices.length) {
while (i < indices.length && segLevels[indices[i]!]! < high) i++
let j = i
while (j < indices.length && segLevels[indices[j]!]! >= high) j++
let a = i, b = j - 1
while (a < b) { const tmp = indices[a]!; indices[a] = indices[b]!; indices[b] = tmp; a++; b-- }
i = j
}
high--
}
return indices
}
// --- Public types ---
type ParaData = {
widths: number[]
isWordLike: boolean[]
isSpace: boolean[]
segLevels: Int8Array | null
breakableWidths: (number[] | null)[]
}
export type PreparedText = {
paraData: ParaData[]
lineHeight: number
}
export type LayoutResult = {
lineCount: number
height: number
}
// --- Public API ---
export function prepare(text: string, font: string, lineHeight?: number): PreparedText {
ctx.font = font
const cache = getWordCache(font)
if (lineHeight === undefined) {
lineHeight = Math.round(parseFontSize(font) * 1.2)
}
const segmenter = new Intl.Segmenter(undefined, { granularity: 'word' })
const normalized = text.replace(/\n/g, ' ')
if (normalized.length === 0 || normalized.trim().length === 0) {
return { paraData: [], lineHeight }
}
const graphemeSegmenter = new Intl.Segmenter(undefined, { granularity: 'grapheme' })
const segments = segmenter.segment(normalized)
const widths: number[] = []
const isWordLike: boolean[] = []
const isSpace: boolean[] = []
const segStarts: number[] = []
const breakableWidths: (number[] | null)[] = []
// Merge punctuation into preceding words: "better." as one unit
const rawSegs = [...segments]
const merged: { text: string, isWordLike: boolean, isSpace: boolean, start: number }[] = []
for (let i = 0; i < rawSegs.length; i++) {
const s = rawSegs[i]!
const ws = !s.isWordLike && /^\s+$/.test(s.segment)
if (!s.isWordLike && !ws && merged.length > 0) {
merged[merged.length - 1]!.text += s.segment
} else {
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show 5ecce72:src/layout.ts | sed -n '1,260p'"
Chunk ID: d72e62
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 2739
Output:
// DOM-free text measurement for browser environments.
//
// Problem: DOM-based text measurement (getBoundingClientRect, offsetHeight)
// forces synchronous layout reflow. When components independently measure text,
// each measurement triggers a reflow of the entire document. This creates
// read/write interleaving that can cost 30ms+ per frame for 500 text blocks.
//
// Solution: two-phase measurement using canvas measureText (no DOM reads).
// prepare(text, font) — segments text via Intl.Segmenter, measures each word
// via canvas, caches widths. Call once when text first appears.
// layout(prepared, maxWidth) — walks cached word widths with pure arithmetic
// to count lines and compute height. Call on every resize. ~0.0002ms per text.
//
// i18n: Intl.Segmenter handles CJK (per-character breaking), Thai, Arabic, etc.
// Bidi: Unicode Bidirectional Algorithm for mixed LTR/RTL text.
// Punctuation merging: "better." measured as one unit (matches CSS behavior).
// Trailing whitespace: hangs past line edge without triggering breaks (CSS behavior).
// overflow-wrap: pre-measured grapheme widths enable character-level word breaking.
//
// Emoji correction: Chrome/Firefox canvas measures emoji wider than DOM at font
// sizes <24px on macOS (Apple Color Emoji). The inflation is constant per emoji
// grapheme at a given size, font-independent. Auto-detected by comparing canvas
// vs actual DOM emoji width (one cached DOM read per font). Safari canvas and
// DOM agree (both wider than fontSize), so correction = 0 there.
//
// Limitations:
// - system-ui font: canvas resolves to different optical variants than DOM on macOS.
// Use named fonts (Helvetica, Inter, etc.) for guaranteed accuracy.
//
// Based on Sebastian Markbage's text-layout research (github.com/chenglou/text-layout).
const canvas = typeof OffscreenCanvas !== 'undefined'
? new OffscreenCanvas(1, 1)
: document.createElement('canvas')
const ctx = canvas.getContext('2d')!
// Word width cache: font → Map.
// Persists across prepare() calls. Common words ("the", "a", etc.) are measured
// once and shared across all text blocks. Survives resize since font doesn't change.
// No eviction: grows monotonically per font. Typical single-font feed ≈ few KB.
// Call clearCache() to reclaim if needed (e.g. font change, long session).
const wordCaches = new Map>()
function getWordCache(font: string): Map {
let cache = wordCaches.get(font)
if (!cache) {
cache = new Map()
wordCaches.set(font, cache)
}
return cache
}
function measureSegment(seg: string, cache: Map): number {
let w = cache.get(seg)
if (w === undefined) {
w = ctx.measureText(seg).width
cache.set(seg, w)
}
return w
}
function parseFontSize(font: string): number {
const m = font.match(/(\d+(?:\.\d+)?)\s*px/)
return m ? parseFloat(m[1]!) : 16
}
// Emoji correction: canvas measureText inflates emoji widths on Chrome/Firefox
// at font sizes <24px on macOS. The inflation is per-emoji-grapheme, constant
// across all emoji types (simple, ZWJ, flags, skin tones, keycaps) and all font
// families. Auto-detected by comparing canvas vs DOM emoji width (one cached
// DOM read per font). Safari canvas and DOM agree, so correction = 0.
const emojiPresentationRe = /\p{Emoji_Presentation}/u
// Shared segmenters: hoisted to module level to avoid per-prepare() construction.
// Intl.Segmenter construction loads ICU data internally — expensive to repeat.
// Captures the default locale at module load time. If locale support is needed
// in the future, expose a function to reinitialize these with a new locale.
const sharedWordSegmenter = new Intl.Segmenter(undefined, { granularity: 'word' })
const sharedGraphemeSegmenter = new Intl.Segmenter(undefined, { granularity: 'grapheme' })
function isEmojiGrapheme(g: string): boolean {
return emojiPresentationRe.test(g) || g.includes('\uFE0F')
}
const emojiCorrectionCache = new Map()
function getEmojiCorrection(font: string, fontSize: number): number {
let correction = emojiCorrectionCache.get(font)
if (correction !== undefined) return correction
ctx.font = font
const canvasW = ctx.measureText('\u{1F600}').width
correction = 0
if (canvasW > fontSize + 0.5) {
const span = document.createElement('span')
span.style.font = font
span.style.display = 'inline-block'
span.style.visibility = 'hidden'
span.style.position = 'absolute'
span.textContent = '\u{1F600}'
document.body.appendChild(span)
const domW = span.getBoundingClientRect().width
document.body.removeChild(span)
if (canvasW - domW > 0.5) {
correction = canvasW - domW
}
}
emojiCorrectionCache.set(font, correction)
return correction
}
function countEmojiGraphemes(text: string): number {
let count = 0
for (const g of sharedGraphemeSegmenter.segment(text)) {
if (isEmojiGrapheme(g.segment)) count++
}
return count
}
// CJK characters don't use spaces between words. Intl.Segmenter with
// granularity 'word' groups them into multi-character words, but CSS allows
// line breaks between any CJK characters. We detect CJK segments and split
// them into individual graphemes so each character is a valid break point.
function isCJK(s: string): boolean {
for (let i = 0; i < s.length; i++) {
const c = s.charCodeAt(i)
if ((c >= 0x4E00 && c <= 0x9FFF) || // CJK Unified
(c >= 0x3400 && c <= 0x4DBF) || // CJK Extension A
(c >= 0x3000 && c <= 0x303F) || // CJK Punctuation
(c >= 0x3040 && c <= 0x309F) || // Hiragana
(c >= 0x30A0 && c <= 0x30FF) || // Katakana
(c >= 0xAC00 && c <= 0xD7AF) || // Hangul
(c >= 0xFF00 && c <= 0xFFEF)) { // Fullwidth
return true
}
}
return false
}
function isWhitespace(s: string): boolean {
for (let i = 0; i < s.length; i++) {
const c = s.charCodeAt(i)
if (c !== 0x20 && c !== 0x09 && c !== 0x0A && c !== 0x0D && c !== 0x0C && c !== 0xA0) {
return false
}
}
return true
}
// Kinsoku shori (禁則処理): CJK line-breaking rules.
// Line-start prohibition: these characters cannot start a new line.
// To prevent this, they are merged with the preceding grapheme during
// CJK splitting, keeping them together as one unit.
const kinsokuStart = new Set([
// Fullwidth punctuation
'\uFF0C', // ，
'\uFF0E', // ．
'\uFF01', // ！
'\uFF1A', // ：
'\uFF1B', // ；
'\uFF1F', // ？
// CJK punctuation
'\u3001', // 、
'\u3002', // 。
'\u30FB', // ・
// Closing brackets
'\uFF09', // ）
'\u3015', // 〕
'\u3009', // 〉
'\u300B', // 》
'\u300D', // 」
'\u300F', // 』
'\u3011', // 】
'\u3017', // 〗
'\u3019', // 〙
'\u301B', // 〛
// Prolonged sound mark, iteration marks
'\u30FC', // ー
'\u3005', // 々
'\u303B', // 〻
])
// Line-end prohibition: these characters cannot end a line (UAX #14 class OP +
// CJK opening brackets). To prevent this, they are merged with the following
// grapheme in CJK splitting, and with the following word in general merging.
const kinsokuEnd = new Set([
// ASCII/Latin
'(', '[', '{',
// CJK fullwidth
'\uFF08', // （
'\u3014', // 〔
'\u3008', // 〈
'\u300A', // 《
'\u300C', // 「
'\u300E', // 『
'\u3010', // 【
'\u3016', // 〖
'\u3018', // 〘
'\u301A', // 〚
])
// Unicode Bidirectional Algorithm (UAX #9), forked from pdf.js via Sebastian's
// text-layout. Classifies characters into bidi types, computes embedding levels,
// and reorders segments within each line for correct visual display of mixed
// LTR/RTL text. Only needed for paragraphs containing RTL characters; pure LTR
// text fast-paths with null levels (zero overhead).
type BidiType = 'L' | 'R' | 'AL' | 'AN' | 'EN' | 'ES' | 'ET' | 'CS' |
'ON' | 'BN' | 'B' | 'S' | 'WS' | 'NSM'
const baseTypes: BidiType[] = [
'BN','BN','BN','BN','BN','BN','BN','BN','BN','S','B','S','WS',
'B','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN',
'BN','BN','B','B','B','S','WS','ON','ON','ET','ET','ET','ON',
'ON','ON','ON','ON','ON','CS','ON','CS','ON','EN','EN','EN',
'EN','EN','EN','EN','EN','EN','EN','ON','ON','ON','ON','ON',
'ON','ON','L','L','L','L','L','L','L','L','L','L','L','L','L',
'L','L','L','L','L','L','L','L','L','L','L','L','L','ON','ON',
'ON','ON','ON','ON','L','L','L','L','L','L','L','L','L','L',
'L','L','L','L','L','L','L','L','L','L','L','L','L','L','L',
'L','ON','ON','ON','ON','BN','BN','BN','BN','BN','BN','B','BN',
'BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN',
'BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN',
'BN','CS','ON','ET','ET','ET','ET','ON','ON','ON','ON','L','ON',
'ON','ON','ON','ON','ET','ET','EN','EN','ON','L','ON','ON','ON',
'EN','L','ON','ON','ON','ON','ON','L','L','L','L','L','L','L',
'L','L','L','L','L','L','L','L','L','L','L','L','L','L','L',
'L','ON','L','L','L','L','L','L','L','L','L','L','L','L','L',
'L','L','L','L','L','L','L','L','L','L','L','L','L','L','L',
'L','L','L','ON','L','L','L','L','L','L','L','L'
]
const arabicTypes: BidiType[] = [
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'CS','AL','ON','ON','NSM','NSM','NSM','NSM','NSM','NSM','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','NSM','NSM','NSM','NSM','NSM','NSM','NSM',
'NSM','NSM','NSM','NSM','NSM','NSM','NSM','AL','AL','AL','AL',
'AL','AL','AL','AN','AN','AN','AN','AN','AN','AN','AN','AN',
'AN','ET','AN','AN','AL','AL','AL','NSM','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','NSM','NSM','NSM','NSM','NSM','NSM','NSM','NSM','NSM','NSM',
'NSM','NSM','NSM','NSM','NSM','NSM','NSM','NSM','NSM','ON','NSM',
'NSM','NSM','NSM','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL'
]
function classifyChar(charCode: number): BidiType {
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show fea1fa7:src/layout.ts | sed -n '1,260p'"
Chunk ID: dd09ff
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 2752
Output:
// Text measurement for browser environments using canvas measureText.
//
// Problem: DOM-based text measurement (getBoundingClientRect, offsetHeight)
// forces synchronous layout reflow. When components independently measure text,
// each measurement triggers a reflow of the entire document. This creates
// read/write interleaving that can cost 30ms+ per frame for 500 text blocks.
//
// Solution: two-phase measurement centered around canvas measureText.
// prepare(text, font) — segments text via Intl.Segmenter, measures each word
// via canvas, caches widths, and does one cached DOM calibration read per
// font when emoji correction is needed. Call once when text first appears.
// layout(prepared, maxWidth) — walks cached word widths with pure arithmetic
// to count lines and compute height. Call on every resize. ~0.0002ms per text.
//
// i18n: Intl.Segmenter handles CJK (per-character breaking), Thai, Arabic, etc.
// Bidi: Unicode Bidirectional Algorithm for mixed LTR/RTL text.
// Punctuation merging: "better." measured as one unit (matches CSS behavior).
// Trailing whitespace: hangs past line edge without triggering breaks (CSS behavior).
// overflow-wrap: pre-measured grapheme widths enable character-level word breaking.
//
// Emoji correction: Chrome/Firefox canvas measures emoji wider than DOM at font
// sizes <24px on macOS (Apple Color Emoji). The inflation is constant per emoji
// grapheme at a given size, font-independent. Auto-detected by comparing canvas
// vs actual DOM emoji width (one cached DOM read per font). Safari canvas and
// DOM agree (both wider than fontSize), so correction = 0 there.
//
// Limitations:
// - system-ui font: canvas resolves to different optical variants than DOM on macOS.
// Use named fonts (Helvetica, Inter, etc.) for guaranteed accuracy.
//
// Based on Sebastian Markbage's text-layout research (github.com/chenglou/text-layout).
const canvas = typeof OffscreenCanvas !== 'undefined'
? new OffscreenCanvas(1, 1)
: document.createElement('canvas')
const ctx = canvas.getContext('2d')!
// Word width cache: font → Map.
// Persists across prepare() calls. Common words ("the", "a", etc.) are measured
// once and shared across all text blocks. Survives resize since font doesn't change.
// No eviction: grows monotonically per font. Typical single-font feed ≈ few KB.
// Call clearCache() to reclaim if needed (e.g. font change, long session).
const wordCaches = new Map>()
function getWordCache(font: string): Map {
let cache = wordCaches.get(font)
if (!cache) {
cache = new Map()
wordCaches.set(font, cache)
}
return cache
}
function measureSegment(seg: string, cache: Map): number {
let w = cache.get(seg)
if (w === undefined) {
w = ctx.measureText(seg).width
cache.set(seg, w)
}
return w
}
function parseFontSize(font: string): number {
const m = font.match(/(\d+(?:\.\d+)?)\s*px/)
return m ? parseFloat(m[1]!) : 16
}
// Emoji correction: canvas measureText inflates emoji widths on Chrome/Firefox
// at font sizes <24px on macOS. The inflation is per-emoji-grapheme, constant
// across all emoji types (simple, ZWJ, flags, skin tones, keycaps) and all font
// families. Auto-detected by comparing canvas vs DOM emoji width (one cached
// DOM read per font). Safari canvas and DOM agree, so correction = 0.
const emojiPresentationRe = /\p{Emoji_Presentation}/u
// Shared segmenters: hoisted to module level to avoid per-prepare() construction.
// Intl.Segmenter construction loads ICU data internally — expensive to repeat.
// Captures the default locale at module load time. If locale support is needed
// in the future, expose a function to reinitialize these with a new locale.
const sharedWordSegmenter = new Intl.Segmenter(undefined, { granularity: 'word' })
const sharedGraphemeSegmenter = new Intl.Segmenter(undefined, { granularity: 'grapheme' })
function isEmojiGrapheme(g: string): boolean {
return emojiPresentationRe.test(g) || g.includes('\uFE0F')
}
const emojiCorrectionCache = new Map()
function getEmojiCorrection(font: string, fontSize: number): number {
let correction = emojiCorrectionCache.get(font)
if (correction !== undefined) return correction
ctx.font = font
const canvasW = ctx.measureText('\u{1F600}').width
correction = 0
if (canvasW > fontSize + 0.5) {
const span = document.createElement('span')
span.style.font = font
span.style.display = 'inline-block'
span.style.visibility = 'hidden'
span.style.position = 'absolute'
span.textContent = '\u{1F600}'
document.body.appendChild(span)
const domW = span.getBoundingClientRect().width
document.body.removeChild(span)
if (canvasW - domW > 0.5) {
correction = canvasW - domW
}
}
emojiCorrectionCache.set(font, correction)
return correction
}
function countEmojiGraphemes(text: string): number {
let count = 0
for (const g of sharedGraphemeSegmenter.segment(text)) {
if (isEmojiGrapheme(g.segment)) count++
}
return count
}
// CJK characters don't use spaces between words. Intl.Segmenter with
// granularity 'word' groups them into multi-character words, but CSS allows
// line breaks between any CJK characters. We detect CJK segments and split
// them into individual graphemes so each character is a valid break point.
function isCJK(s: string): boolean {
for (let i = 0; i < s.length; i++) {
const c = s.charCodeAt(i)
if ((c >= 0x4E00 && c <= 0x9FFF) || // CJK Unified
(c >= 0x3400 && c <= 0x4DBF) || // CJK Extension A
(c >= 0x3000 && c <= 0x303F) || // CJK Punctuation
(c >= 0x3040 && c <= 0x309F) || // Hiragana
(c >= 0x30A0 && c <= 0x30FF) || // Katakana
(c >= 0xAC00 && c <= 0xD7AF) || // Hangul
(c >= 0xFF00 && c <= 0xFFEF)) { // Fullwidth
return true
}
}
return false
}
function isWhitespace(s: string): boolean {
for (let i = 0; i < s.length; i++) {
const c = s.charCodeAt(i)
if (c !== 0x20 && c !== 0x09 && c !== 0x0A && c !== 0x0D && c !== 0x0C && c !== 0xA0) {
return false
}
}
return true
}
// Kinsoku shori (禁則処理): CJK line-breaking rules.
// Line-start prohibition: these characters cannot start a new line.
// To prevent this, they are merged with the preceding grapheme during
// CJK splitting, keeping them together as one unit.
const kinsokuStart = new Set([
// Fullwidth punctuation
'\uFF0C', // ，
'\uFF0E', // ．
'\uFF01', // ！
'\uFF1A', // ：
'\uFF1B', // ；
'\uFF1F', // ？
// CJK punctuation
'\u3001', // 、
'\u3002', // 。
'\u30FB', // ・
// Closing brackets
'\uFF09', // ）
'\u3015', // 〕
'\u3009', // 〉
'\u300B', // 》
'\u300D', // 」
'\u300F', // 』
'\u3011', // 】
'\u3017', // 〗
'\u3019', // 〙
'\u301B', // 〛
// Prolonged sound mark, iteration marks
'\u30FC', // ー
'\u3005', // 々
'\u303B', // 〻
])
// Line-end prohibition: these characters cannot end a line (UAX #14 class OP +
// CJK opening brackets). To prevent this, they are merged with the following
// grapheme in CJK splitting, and with the following word in general merging.
const kinsokuEnd = new Set([
// ASCII/Latin
'(', '[', '{',
// CJK fullwidth
'\uFF08', // （
'\u3014', // 〔
'\u3008', // 〈
'\u300A', // 《
'\u300C', // 「
'\u300E', // 『
'\u3010', // 【
'\u3016', // 〖
'\u3018', // 〘
'\u301A', // 〚
])
// Unicode Bidirectional Algorithm (UAX #9), forked from pdf.js via Sebastian's
// text-layout. Classifies characters into bidi types, computes embedding levels,
// and reorders segments within each line for correct visual display of mixed
// LTR/RTL text. Only needed for paragraphs containing RTL characters; pure LTR
// text fast-paths with null levels (zero overhead).
type BidiType = 'L' | 'R' | 'AL' | 'AN' | 'EN' | 'ES' | 'ET' | 'CS' |
'ON' | 'BN' | 'B' | 'S' | 'WS' | 'NSM'
const baseTypes: BidiType[] = [
'BN','BN','BN','BN','BN','BN','BN','BN','BN','S','B','S','WS',
'B','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN',
'BN','BN','B','B','B','S','WS','ON','ON','ET','ET','ET','ON',
'ON','ON','ON','ON','ON','CS','ON','CS','ON','EN','EN','EN',
'EN','EN','EN','EN','EN','EN','EN','ON','ON','ON','ON','ON',
'ON','ON','L','L','L','L','L','L','L','L','L','L','L','L','L',
'L','L','L','L','L','L','L','L','L','L','L','L','L','ON','ON',
'ON','ON','ON','ON','L','L','L','L','L','L','L','L','L','L',
'L','L','L','L','L','L','L','L','L','L','L','L','L','L','L',
'L','ON','ON','ON','ON','BN','BN','BN','BN','BN','BN','B','BN',
'BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN',
'BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN','BN',
'BN','CS','ON','ET','ET','ET','ET','ON','ON','ON','ON','L','ON',
'ON','ON','ON','ON','ET','ET','EN','EN','ON','L','ON','ON','ON',
'EN','L','ON','ON','ON','ON','ON','L','L','L','L','L','L','L',
'L','L','L','L','L','L','L','L','L','L','L','L','L','L','L',
'L','ON','L','L','L','L','L','L','L','L','L','L','L','L','L',
'L','L','L','L','L','L','L','L','L','L','L','L','L','L','L',
'L','L','L','ON','L','L','L','L','L','L','L','L'
]
const arabicTypes: BidiType[] = [
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'CS','AL','ON','ON','NSM','NSM','NSM','NSM','NSM','NSM','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','NSM','NSM','NSM','NSM','NSM','NSM','NSM',
'NSM','NSM','NSM','NSM','NSM','NSM','NSM','AL','AL','AL','AL',
'AL','AL','AL','AN','AN','AN','AN','AN','AN','AN','AN','AN',
'AN','ET','AN','AN','AL','AL','AL','NSM','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','NSM','NSM','NSM','NSM','NSM','NSM','NSM','NSM','NSM','NSM',
'NSM','NSM','NSM','NSM','NSM','NSM','NSM','NSM','NSM','ON','NSM',
'NSM','NSM','NSM','AL','AL','AL','AL','AL','AL','AL','AL','AL',
'AL','AL','AL','AL','AL','AL','AL','AL','AL'
]
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show fea1fa7:src/layout.ts | rg -n \"export function|type LayoutLine|type LayoutCursor|function layoutInternal\"",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show fea1fa7:src/layout.ts | sed -n '520,780p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show f06fb75:src/line-break.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show 3e991df:src/layout.ts | rg -n \"layoutNextLine|walkLineRanges|layoutWithLines|countPreparedLines|walkPreparedLines\"",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc 'cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show fea1fa7:src/layout.ts | rg -n "export function|type LayoutLine|type LayoutCursor|function layoutInternal"'
Chunk ID: fc62b3
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 145
Output:
352:export type LayoutLine = {
357:export type LayoutLinesResult = LayoutResult & {
532:export function prepare(text: string, font: string, lineHeight?: number): PreparedText {
538:export function prepareWithSegments(text: string, font: string, lineHeight?: number): PreparedTextWithSegments {
550:export function layout(prepared: PreparedText, maxWidth: number, lineHeight?: number): LayoutResult {
622:export function layoutWithLines(prepared: PreparedTextWithSegments, maxWidth: number, lineHeight?: number): LayoutLinesResult {
718:export function clearCache(): void {
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show fea1fa7:src/layout.ts | sed -n '520,780p'"
Chunk ID: 400795
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 1578
Output:
// (e.g. when a comment first appears). The result is width-independent — the
// same PreparedText can be laid out at any maxWidth via layout().
//
// Steps:
// 1. Normalize newlines to spaces (CSS white-space: normal behavior)
// 2. Segment via Intl.Segmenter (handles CJK, Thai, etc.)
// 3. Merge punctuation into preceding word ("better." as one unit)
// 4. Split CJK words into individual graphemes (per-character line breaks)
// 5. Measure each segment via canvas measureText, cache by (segment, font)
// 6. Pre-measure graphemes of long words (for overflow-wrap: break-word)
// 7. Correct emoji canvas inflation (auto-detected per font size)
// 8. Compute bidi embedding levels for mixed-direction text
export function prepare(text: string, font: string, lineHeight?: number): PreparedText {
return prepareInternal(text, font, lineHeight, false) as PreparedText
}
// Rich variant used by callers that need enough information to render the
// laid-out lines themselves.
export function prepareWithSegments(text: string, font: string, lineHeight?: number): PreparedTextWithSegments {
return prepareInternal(text, font, lineHeight, true) as PreparedTextWithSegments
}
// Layout prepared text at a given max width. Pure arithmetic on cached widths —
// no canvas calls, no DOM reads, no string operations, no allocations.
// ~0.0002ms per text block. Call on every resize.
//
// Line breaking rules (matching CSS white-space: normal + overflow-wrap: break-word):
// - Break before any non-space segment that would overflow the line
// - Trailing whitespace hangs past the line edge (doesn't trigger breaks)
// - Segments wider than maxWidth are broken at grapheme boundaries
export function layout(prepared: PreparedText, maxWidth: number, lineHeight?: number): LayoutResult {
if (lineHeight === undefined) lineHeight = prepared.lineHeight
const { widths, isSpace: isSp, breakableWidths } = prepared
if (widths.length === 0) return { lineCount: 0, height: 0 }
let lineCount = 0
let lineW = 0
let hasContent = false
for (let i = 0; i < widths.length; i++) {
const w = widths[i]!
if (!hasContent) {
if (w > maxWidth && breakableWidths[i] !== null) {
const gWidths = breakableWidths[i]!
lineW = 0
for (let g = 0; g < gWidths.length; g++) {
const gw = gWidths[g]!
if (lineW > 0 && lineW + gw > maxWidth) {
lineCount++
lineW = gw
} else {
if (lineW === 0) lineCount++
lineW += gw
}
}
} else {
lineW = w
lineCount++
}
hasContent = true
continue
}
const newW = lineW + w
if (newW > maxWidth) {
if (isSp[i]) continue // trailing whitespace hangs (CSS behavior)
if (w > maxWidth && breakableWidths[i] !== null) {
// Segment wider than line — break at grapheme boundaries
const gWidths = breakableWidths[i]!
lineW = 0
for (let g = 0; g < gWidths.length; g++) {
const gw = gWidths[g]!
if (lineW > 0 && lineW + gw > maxWidth) {
lineCount++
lineW = gw
} else {
if (lineW === 0) lineCount++
lineW += gw
}
}
} else {
lineCount++
lineW = w
}
} else {
lineW = newW
}
}
if (!hasContent) {
lineCount++
}
return { lineCount, height: lineCount * lineHeight }
}
// Rich layout API for callers that want the actual line contents and widths.
// Mirrors layout()'s break decisions, but keeps extra per-line bookkeeping so it
// should stay off the resize hot path.
export function layoutWithLines(prepared: PreparedTextWithSegments, maxWidth: number, lineHeight?: number): LayoutLinesResult {
if (lineHeight === undefined) lineHeight = prepared.lineHeight
const { widths, isSpace: isSp, breakableWidths, segments } = prepared
const lines: LayoutLine[] = []
if (widths.length === 0) return { lineCount: 0, height: 0, lineHeight, lines }
let lineCount = 0
let lineW = 0
let hasContent = false
let currentLine = ''
function pushCurrentLine(): void {
lines.push({ text: currentLine, width: lineW })
currentLine = ''
}
function layoutBreakableSegment(segIndex: number, closeExistingLine: boolean): void {
const gWidths = breakableWidths[segIndex]!
const gTexts: string[] = []
let gTextCount = 0
for (const gs of sharedGraphemeSegmenter.segment(segments[segIndex]!)) {
gTexts[gTextCount] = gs.segment
gTextCount++
}
if (closeExistingLine) pushCurrentLine()
lineW = 0
currentLine = ''
for (let g = 0; g < gWidths.length; g++) {
const gw = gWidths[g]!
const gText = gTexts[g]!
if (lineW > 0 && lineW + gw > maxWidth) {
pushCurrentLine()
lineCount++
lineW = gw
currentLine = gText
} else {
if (lineW === 0) {
lineCount++
lineW = gw
currentLine = gText
} else {
lineW += gw
currentLine += gText
}
}
}
}
for (let i = 0; i < widths.length; i++) {
const w = widths[i]!
const segText = segments[i]!
if (!hasContent) {
if (w > maxWidth && breakableWidths[i] !== null) {
layoutBreakableSegment(i, false)
} else {
lineW = w
lineCount++
currentLine = segText
}
hasContent = true
continue
}
const newW = lineW + w
if (newW > maxWidth) {
if (isSp[i]) continue
if (w > maxWidth && breakableWidths[i] !== null) {
layoutBreakableSegment(i, true)
} else {
pushCurrentLine()
lineCount++
lineW = w
currentLine = segText
}
} else {
lineW = newW
currentLine += segText
}
}
if (!hasContent) {
lineCount++
} else {
pushCurrentLine()
}
return { lineCount, height: lineCount * lineHeight, lineHeight, lines }
}
export function clearCache(): void {
wordCaches.clear()
emojiCorrectionCache.clear()
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show f06fb75:src/line-break.ts | sed -n '1,260p'"
Chunk ID: 9e2d86
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 1837
Output:
import type { SegmentBreakKind } from './analysis.ts'
import { getEngineProfile } from './measurement.ts'
export type LineBreakCursor = {
segmentIndex: number
graphemeIndex: number
}
export type PreparedLineBreakData = {
widths: number[]
kinds: SegmentBreakKind[]
breakableWidths: (number[] | null)[]
discretionaryHyphenWidth: number
}
export type InternalLayoutLine = {
startSegmentIndex: number
startGraphemeIndex: number
endSegmentIndex: number
endGraphemeIndex: number
width: number
discretionaryHyphenBeforeSegmentIndex: number
}
function isCollapsibleSpaceKind(kind: SegmentBreakKind): boolean {
return kind === 'space'
}
export function normalizeLineStart(
prepared: PreparedLineBreakData,
start: LineBreakCursor,
): LineBreakCursor | null {
let segmentIndex = start.segmentIndex
const graphemeIndex = start.graphemeIndex
if (segmentIndex >= prepared.widths.length) return null
if (graphemeIndex > 0) return start
while (segmentIndex < prepared.widths.length) {
const kind = prepared.kinds[segmentIndex]!
if (kind !== 'space' && kind !== 'zero-width-break' && kind !== 'soft-hyphen') {
break
}
segmentIndex++
}
if (segmentIndex >= prepared.widths.length) return null
return { segmentIndex, graphemeIndex: 0 }
}
export function countPreparedLines(prepared: PreparedLineBreakData, maxWidth: number): number {
const { widths, kinds, breakableWidths } = prepared
if (widths.length === 0) return 0
const lineFitEpsilon = getEngineProfile().lineFitEpsilon
if (kinds.includes('soft-hyphen')) {
return walkPreparedLines(prepared, maxWidth)
}
let lineCount = 0
let lineW = 0
let hasContent = false
function placeOnFreshLine(segmentIndex: number): void {
const w = widths[segmentIndex]!
if (w > maxWidth && breakableWidths[segmentIndex] !== null) {
const gWidths = breakableWidths[segmentIndex]!
lineW = 0
for (let g = 0; g < gWidths.length; g++) {
const gw = gWidths[g]!
if (lineW > 0 && lineW + gw > maxWidth + lineFitEpsilon) {
lineCount++
lineW = gw
} else {
if (lineW === 0) lineCount++
lineW += gw
}
}
} else {
lineW = w
lineCount++
}
hasContent = true
}
for (let i = 0; i < widths.length; i++) {
const w = widths[i]!
const kind = kinds[i]!
if (!hasContent) {
placeOnFreshLine(i)
continue
}
const newW = lineW + w
if (newW > maxWidth + lineFitEpsilon) {
if (isCollapsibleSpaceKind(kind)) {
continue
}
lineW = 0
hasContent = false
placeOnFreshLine(i)
} else {
lineW = newW
}
}
if (!hasContent) {
lineCount++
}
return lineCount
}
export function walkPreparedLines(
prepared: PreparedLineBreakData,
maxWidth: number,
onLine?: (line: InternalLayoutLine) => void,
): number {
const { widths, kinds, breakableWidths, discretionaryHyphenWidth } = prepared
if (widths.length === 0) return 0
const lineFitEpsilon = getEngineProfile().lineFitEpsilon
let lineCount = 0
let lineW = 0
let hasContent = false
let lineStartSegmentIndex = 0
let lineStartGraphemeIndex = 0
let lineEndSegmentIndex = 0
let lineEndGraphemeIndex = 0
let pendingSoftBreakSegmentIndex = -1
let pendingSoftBreakWidth = 0
function clearPendingSoftBreak(): void {
pendingSoftBreakSegmentIndex = -1
pendingSoftBreakWidth = 0
}
function emitCurrentLine(
endSegmentIndex = lineEndSegmentIndex,
endGraphemeIndex = lineEndGraphemeIndex,
width = lineW,
discretionaryHyphenBeforeSegmentIndex = -1,
): void {
lineCount++
onLine?.({
startSegmentIndex: lineStartSegmentIndex,
startGraphemeIndex: lineStartGraphemeIndex,
endSegmentIndex,
endGraphemeIndex,
width,
discretionaryHyphenBeforeSegmentIndex,
})
lineW = 0
hasContent = false
clearPendingSoftBreak()
}
function startLineAtSegment(segmentIndex: number, width: number): void {
hasContent = true
lineStartSegmentIndex = segmentIndex
lineStartGraphemeIndex = 0
lineEndSegmentIndex = segmentIndex + 1
lineEndGraphemeIndex = 0
lineW = width
}
function startLineAtGrapheme(segmentIndex: number, graphemeIndex: number, width: number): void {
hasContent = true
lineStartSegmentIndex = segmentIndex
lineStartGraphemeIndex = graphemeIndex
lineEndSegmentIndex = segmentIndex
lineEndGraphemeIndex = graphemeIndex + 1
lineW = width
}
function appendWholeSegment(segmentIndex: number, width: number): void {
if (!hasContent) {
startLineAtSegment(segmentIndex, width)
return
}
lineW += width
lineEndSegmentIndex = segmentIndex + 1
lineEndGraphemeIndex = 0
}
function appendBreakableSegment(segmentIndex: number): void {
appendBreakableSegmentFrom(segmentIndex, 0)
}
function appendBreakableSegmentFrom(segmentIndex: number, startGraphemeIndex: number): void {
const gWidths = breakableWidths[segmentIndex]!
for (let g = startGraphemeIndex; g < gWidths.length; g++) {
const gw = gWidths[g]!
if (!hasContent) {
startLineAtGrapheme(segmentIndex, g, gw)
continue
}
if (lineW + gw > maxWidth + lineFitEpsilon) {
emitCurrentLine()
startLineAtGrapheme(segmentIndex, g, gw)
} else {
lineW += gw
lineEndSegmentIndex = segmentIndex
lineEndGraphemeIndex = g + 1
}
}
if (hasContent && lineEndSegmentIndex === segmentIndex && lineEndGraphemeIndex === gWidths.length) {
lineEndSegmentIndex = segmentIndex + 1
lineEndGraphemeIndex = 0
}
}
function continueSoftHyphenBreakableSegment(segmentIndex: number): boolean {
const gWidths = breakableWidths[segmentIndex]!
if (gWidths === null) return false
let fitCount = 0
let fittedWidth = lineW
while (fitCount < gWidths.length) {
const nextWidth = fittedWidth + gWidths[fitCount]!
const nextLineWidth = fitCount + 1 < gWidths.length
? nextWidth + discretionaryHyphenWidth
: nextWidth
if (nextLineWidth > maxWidth + lineFitEpsilon) break
fittedWidth = nextWidth
fitCount++
}
if (fitCount === 0) return false
lineW = fittedWidth
lineEndSegmentIndex = segmentIndex
lineEndGraphemeIndex = fitCount
clearPendingSoftBreak()
if (fitCount === gWidths.length) {
lineEndSegmentIndex = segmentIndex + 1
lineEndGraphemeIndex = 0
return true
}
emitCurrentLine(segmentIndex, fitCount, fittedWidth + discretionaryHyphenWidth, segmentIndex)
appendBreakableSegmentFrom(segmentIndex, fitCount)
return true
}
for (let i = 0; i < widths.length; i++) {
const w = widths[i]!
const kind = kinds[i]!
if (kind === 'soft-hyphen') {
if (hasContent) {
lineEndSegmentIndex = i + 1
lineEndGraphemeIndex = 0
pendingSoftBreakSegmentIndex = i + 1
pendingSoftBreakWidth = lineW + discretionaryHyphenWidth
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc 'cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show 3e991df:src/layout.ts | rg -n "layoutNextLine|walkLineRanges|layoutWithLines|countPreparedLines|walkPreparedLines"'
Chunk ID: 96c110
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 76
Output:
847:function walkPreparedLines(
976: const lineCount = walkPreparedLines(prepared, maxWidth)
1028:export function layoutWithLines(prepared: PreparedTextWithSegments, maxWidth: number, lineHeight: number): LayoutLinesResult {
1033: const lineCount = walkPreparedLines(prepared, maxWidth, line => {
```
## Assistant
The history fills in the design arc. The very first version bundled bidi, CJK, measurement, and layout into one file. Then came a flattening/specialization phase, then a split between the hot path and the rich path, and then a deeper extraction where line breaking became its own core that both `layout()` and the richer APIs share. That’s not cosmetic refactoring; it’s the code converging on what the product actually is.
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/layout.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/layout.ts | sed -n '260,520p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/layout.ts | sed -n '520,760p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/measurement.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/layout.ts | sed -n '1,260p'"
Chunk ID: 9f9d80
Wall time: 0.0001 seconds
Process exited with code 0
Original token count: 2954
Output:
1 // Text measurement for browser environments using canvas measureText.
2 //
3 // Problem: DOM-based text measurement (getBoundingClientRect, offsetHeight)
4 // forces synchronous layout reflow. When components independently measure text,
5 // each measurement triggers a reflow of the entire document. This creates
6 // read/write interleaving that can cost 30ms+ per frame for 500 text blocks.
7 //
8 // Solution: two-phase measurement centered around canvas measureText.
9 // prepare(text, font) — segments text via Intl.Segmenter, measures each word
10 // via canvas, caches widths, and does one cached DOM calibration read per
11 // font when emoji correction is needed. Call once when text first appears.
12 // layout(prepared, maxWidth, lineHeight) — walks cached word widths with pure
13 // arithmetic to count lines and compute height. Call on every resize.
14 // ~0.0002ms per text.
15 //
16 // i18n: Intl.Segmenter handles CJK (per-character breaking), Thai, Arabic, etc.
17 // Bidi: simplified rich-path metadata for mixed LTR/RTL custom rendering.
18 // Punctuation merging: "better." measured as one unit (matches CSS behavior).
19 // Trailing whitespace: hangs past line edge without triggering breaks (CSS behavior).
20 // overflow-wrap: pre-measured grapheme widths enable character-level word breaking.
21 //
22 // Emoji correction: Chrome/Firefox canvas measures emoji wider than DOM at font
23 // sizes <24px on macOS (Apple Color Emoji). The inflation is constant per emoji
24 // grapheme at a given size, font-independent. Auto-detected by comparing canvas
25 // vs actual DOM emoji width (one cached DOM read per font). Safari canvas and
26 // DOM agree (both wider than fontSize), so correction = 0 there.
27 //
28 // Limitations:
29 // - system-ui font: canvas resolves to different optical variants than DOM on macOS.
30 // Use named fonts (Helvetica, Inter, etc.) for guaranteed accuracy.
31 // See RESEARCH.md "Discovery: system-ui font resolution mismatch".
32 //
33 // Based on Sebastian Markbage's text-layout research (github.com/chenglou/text-layout).
34
35 import { computeSegmentLevels } from './bidi.js'
36 import {
37 analyzeText,
38 clearAnalysisCaches,
39 endsWithClosingQuote,
40 isCJK,
41 kinsokuEnd,
42 kinsokuStart,
43 leftStickyPunctuation,
44 setAnalysisLocale,
45 type AnalysisChunk,
46 type SegmentBreakKind,
47 type TextAnalysis,
48 type WhiteSpaceMode,
49 } from './analysis.js'
50 import {
51 clearMeasurementCaches,
52 getCorrectedSegmentWidth,
53 getEngineProfile,
54 getFontMeasurementState,
55 getSegmentGraphemePrefixWidths,
56 getSegmentGraphemeWidths,
57 getSegmentMetrics,
58 textMayContainEmoji,
59 } from './measurement.js'
60 import {
61 countPreparedLines,
62 layoutNextLineRange as stepPreparedLineRange,
63 walkPreparedLines,
64 type InternalLayoutLine,
65 } from './line-break.js'
66
67 let sharedGraphemeSegmenter: Intl.Segmenter | null = null
68 // Rich-path only. Reuses grapheme splits while materializing multiple lines
69 // from the same prepared handle, without pushing that cache into the API.
70 let sharedLineTextCaches = new WeakMap>()
71
72 function getSharedGraphemeSegmenter(): Intl.Segmenter {
73 if (sharedGraphemeSegmenter === null) {
74 sharedGraphemeSegmenter = new Intl.Segmenter(undefined, { granularity: 'grapheme' })
75 }
76 return sharedGraphemeSegmenter
77 }
78
79 // --- Public types ---
80
81 declare const preparedTextBrand: unique symbol
82
83 type PreparedCore = {
84 widths: number[] // Segment widths, e.g. [42.5, 4.4, 37.2]
85 lineEndFitAdvances: number[] // Width contribution when a line ends after this segment
86 lineEndPaintAdvances: number[] // Painted width contribution when a line ends after this segment
87 kinds: SegmentBreakKind[] // Break behavior per segment, e.g. ['text', 'space', 'text']
88 simpleLineWalkFastPath: boolean // Normal text can use the simpler old line walker across all layout APIs
89 segLevels: Int8Array | null // Rich-path bidi metadata for custom rendering; layout() never reads it
90 breakableWidths: (number[] | null)[] // Grapheme widths for overflow-wrap segments, else null
91 breakablePrefixWidths: (number[] | null)[] // Cumulative grapheme prefix widths for narrow browser-policy shims
92 discretionaryHyphenWidth: number // Visible width added when a soft hyphen is chosen as the break
93 tabStopAdvance: number // Absolute advance between tab stops for pre-wrap tab segments
94 chunks: PreparedLineChunk[] // Precompiled hard-break chunks for line walking
95 }
96
97 // Keep the main prepared handle opaque so the public API does not accidentally
98 // calcify around the current parallel-array representation.
99 export type PreparedText = {
100 readonly [preparedTextBrand]: true
101 }
102
103 type InternalPreparedText = PreparedText & PreparedCore
104
105 // Rich/diagnostic variant that still exposes the structural segment data.
106 // Treat this as the unstable escape hatch for experiments and custom rendering.
107 export type PreparedTextWithSegments = InternalPreparedText & {
108 segments: string[] // Segment text aligned with the parallel arrays, e.g. ['hello', ' ', 'world']
109 }
110
111 export type LayoutCursor = {
112 segmentIndex: number // Segment index in `segments`
113 graphemeIndex: number // Grapheme index within that segment; `0` at segment boundaries
114 }
115
116 export type LayoutResult = {
117 lineCount: number // Number of wrapped lines, e.g. 3
118 height: number // Total block height, e.g. lineCount * lineHeight = 57
119 }
120
121 export type LayoutLine = {
122 text: string // Full text content of this line, e.g. 'hello world'
123 width: number // Measured width of this line, e.g. 87.5
124 start: LayoutCursor // Inclusive start cursor in prepared segments/graphemes
125 end: LayoutCursor // Exclusive end cursor in prepared segments/graphemes
126 }
127
128 export type LayoutLineRange = {
129 width: number // Measured width of this line, e.g. 87.5
130 start: LayoutCursor // Inclusive start cursor in prepared segments/graphemes
131 end: LayoutCursor // Exclusive end cursor in prepared segments/graphemes
132 }
133
134 export type LayoutLinesResult = LayoutResult & {
135 lines: LayoutLine[] // Per-line text/width pairs for custom rendering
136 }
137
138 export type PrepareProfile = {
139 analysisMs: number
140 measureMs: number
141 totalMs: number
142 analysisSegments: number
143 preparedSegments: number
144 breakableSegments: number
145 }
146
147 export type PrepareOptions = {
148 whiteSpace?: WhiteSpaceMode
149 }
150
151 export type PreparedLineChunk = {
152 startSegmentIndex: number
153 endSegmentIndex: number
154 consumedEndSegmentIndex: number
155 }
156
157 // --- Public API ---
158
159 function createEmptyPrepared(includeSegments: boolean): InternalPreparedText | PreparedTextWithSegments {
160 if (includeSegments) {
161 return {
162 widths: [],
163 lineEndFitAdvances: [],
164 lineEndPaintAdvances: [],
165 kinds: [],
166 simpleLineWalkFastPath: true,
167 segLevels: null,
168 breakableWidths: [],
169 breakablePrefixWidths: [],
170 discretionaryHyphenWidth: 0,
171 tabStopAdvance: 0,
172 chunks: [],
173 segments: [],
174 } as unknown as PreparedTextWithSegments
175 }
176 return {
177 widths: [],
178 lineEndFitAdvances: [],
179 lineEndPaintAdvances: [],
180 kinds: [],
181 simpleLineWalkFastPath: true,
182 segLevels: null,
183 breakableWidths: [],
184 breakablePrefixWidths: [],
185 discretionaryHyphenWidth: 0,
186 tabStopAdvance: 0,
187 chunks: [],
188 } as unknown as InternalPreparedText
189 }
190
191 function measureAnalysis(
192 analysis: TextAnalysis,
193 font: string,
194 includeSegments: boolean,
195 ): InternalPreparedText | PreparedTextWithSegments {
196 const graphemeSegmenter = getSharedGraphemeSegmenter()
197 const engineProfile = getEngineProfile()
198 const { cache, emojiCorrection } = getFontMeasurementState(
199 font,
200 textMayContainEmoji(analysis.normalized),
201 )
202 const discretionaryHyphenWidth = getCorrectedSegmentWidth('-', getSegmentMetrics('-', cache), emojiCorrection)
203 const spaceWidth = getCorrectedSegmentWidth(' ', getSegmentMetrics(' ', cache), emojiCorrection)
204 const tabStopAdvance = spaceWidth * 8
205
206 if (analysis.len === 0) return createEmptyPrepared(includeSegments)
207
208 const widths: number[] = []
209 const lineEndFitAdvances: number[] = []
210 const lineEndPaintAdvances: number[] = []
211 const kinds: SegmentBreakKind[] = []
212 let simpleLineWalkFastPath = analysis.chunks.length <= 1
213 const segStarts = includeSegments ? [] as number[] : null
214 const breakableWidths: (number[] | null)[] = []
215 const breakablePrefixWidths: (number[] | null)[] = []
216 const segments = includeSegments ? [] as string[] : null
217 const preparedStartByAnalysisIndex = Array.from({ length: analysis.len })
218 const preparedEndByAnalysisIndex = Array.from({ length: analysis.len })
219
220 function pushMeasuredSegment(
221 text: string,
222 width: number,
223 lineEndFitAdvance: number,
224 lineEndPaintAdvance: number,
225 kind: SegmentBreakKind,
226 start: number,
227 breakable: number[] | null,
228 breakablePrefix: number[] | null,
229 ): void {
230 if (kind !== 'text' && kind !== 'space' && kind !== 'zero-width-break') {
231 simpleLineWalkFastPath = false
232 }
233 widths.push(width)
234 lineEndFitAdvances.push(lineEndFitAdvance)
235 lineEndPaintAdvances.push(lineEndPaintAdvance)
236 kinds.push(kind)
237 segStarts?.push(start)
238 breakableWidths.push(breakable)
239 breakablePrefixWidths.push(breakablePrefix)
240 if (segments !== null) segments.push(text)
241 }
242
243 for (let mi = 0; mi < analysis.len; mi++) {
244 preparedStartByAnalysisIndex[mi] = widths.length
245 const segText = analysis.texts[mi]!
246 const segWordLike = analysis.isWordLike[mi]!
247 const segKind = analysis.kinds[mi]!
248 const segStart = analysis.starts[mi]!
249
250 if (segKind === 'soft-hyphen') {
251 pushMeasuredSegment(
252 segText,
253 0,
254 discretionaryHyphenWidth,
255 discretionaryHyphenWidth,
256 segKind,
257 segStart,
258 null,
259 null,
260 )
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/layout.ts | sed -n '260,520p'"
Chunk ID: b8a142
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 2826
Output:
260 )
261 preparedEndByAnalysisIndex[mi] = widths.length
262 continue
263 }
264
265 if (segKind === 'hard-break') {
266 pushMeasuredSegment(segText, 0, 0, 0, segKind, segStart, null, null)
267 preparedEndByAnalysisIndex[mi] = widths.length
268 continue
269 }
270
271 if (segKind === 'tab') {
272 pushMeasuredSegment(segText, 0, 0, 0, segKind, segStart, null, null)
273 preparedEndByAnalysisIndex[mi] = widths.length
274 continue
275 }
276
277 const segMetrics = getSegmentMetrics(segText, cache)
278
279 if (segKind === 'text' && segMetrics.containsCJK) {
280 let unitText = ''
281 let unitStart = 0
282
283 for (const gs of graphemeSegmenter.segment(segText)) {
284 const grapheme = gs.segment
285
286 if (unitText.length === 0) {
287 unitText = grapheme
288 unitStart = gs.index
289 continue
290 }
291
292 if (
293 kinsokuEnd.has(unitText) ||
294 kinsokuStart.has(grapheme) ||
295 leftStickyPunctuation.has(grapheme) ||
296 (engineProfile.carryCJKAfterClosingQuote &&
297 isCJK(grapheme) &&
298 endsWithClosingQuote(unitText))
299 ) {
300 unitText += grapheme
301 continue
302 }
303
304 const unitMetrics = getSegmentMetrics(unitText, cache)
305 const w = getCorrectedSegmentWidth(unitText, unitMetrics, emojiCorrection)
306 pushMeasuredSegment(unitText, w, w, w, 'text', segStart + unitStart, null, null)
307
308 unitText = grapheme
309 unitStart = gs.index
310 }
311
312 if (unitText.length > 0) {
313 const unitMetrics = getSegmentMetrics(unitText, cache)
314 const w = getCorrectedSegmentWidth(unitText, unitMetrics, emojiCorrection)
315 pushMeasuredSegment(unitText, w, w, w, 'text', segStart + unitStart, null, null)
316 }
317 preparedEndByAnalysisIndex[mi] = widths.length
318 continue
319 }
320
321 const w = getCorrectedSegmentWidth(segText, segMetrics, emojiCorrection)
322 const lineEndFitAdvance =
323 segKind === 'space' || segKind === 'preserved-space' || segKind === 'zero-width-break'
324 ? 0
325 : w
326 const lineEndPaintAdvance =
327 segKind === 'space' || segKind === 'zero-width-break'
328 ? 0
329 : w
330
331 if (segWordLike && segText.length > 1) {
332 const graphemeWidths = getSegmentGraphemeWidths(segText, segMetrics, cache, emojiCorrection)
333 const graphemePrefixWidths = engineProfile.preferPrefixWidthsForBreakableRuns
334 ? getSegmentGraphemePrefixWidths(segText, segMetrics, cache, emojiCorrection)
335 : null
336 pushMeasuredSegment(
337 segText,
338 w,
339 lineEndFitAdvance,
340 lineEndPaintAdvance,
341 segKind,
342 segStart,
343 graphemeWidths,
344 graphemePrefixWidths,
345 )
346 } else {
347 pushMeasuredSegment(
348 segText,
349 w,
350 lineEndFitAdvance,
351 lineEndPaintAdvance,
352 segKind,
353 segStart,
354 null,
355 null,
356 )
357 }
358 preparedEndByAnalysisIndex[mi] = widths.length
359 }
360
361 const chunks = mapAnalysisChunksToPreparedChunks(analysis.chunks, preparedStartByAnalysisIndex, preparedEndByAnalysisIndex)
362 const segLevels = segStarts === null ? null : computeSegmentLevels(analysis.normalized, segStarts)
363 if (segments !== null) {
364 return {
365 widths,
366 lineEndFitAdvances,
367 lineEndPaintAdvances,
368 kinds,
369 simpleLineWalkFastPath,
370 segLevels,
371 breakableWidths,
372 breakablePrefixWidths,
373 discretionaryHyphenWidth,
374 tabStopAdvance,
375 chunks,
376 segments,
377 } as unknown as PreparedTextWithSegments
378 }
379 return {
380 widths,
381 lineEndFitAdvances,
382 lineEndPaintAdvances,
383 kinds,
384 simpleLineWalkFastPath,
385 segLevels,
386 breakableWidths,
387 breakablePrefixWidths,
388 discretionaryHyphenWidth,
389 tabStopAdvance,
390 chunks,
391 } as unknown as InternalPreparedText
392 }
393
394 function mapAnalysisChunksToPreparedChunks(
395 chunks: AnalysisChunk[],
396 preparedStartByAnalysisIndex: number[],
397 preparedEndByAnalysisIndex: number[],
398 ): PreparedLineChunk[] {
399 const preparedChunks: PreparedLineChunk[] = []
400 for (let i = 0; i < chunks.length; i++) {
401 const chunk = chunks[i]!
402 const startSegmentIndex =
403 chunk.startSegmentIndex < preparedStartByAnalysisIndex.length
404 ? preparedStartByAnalysisIndex[chunk.startSegmentIndex]!
405 : preparedEndByAnalysisIndex[preparedEndByAnalysisIndex.length - 1] ?? 0
406 const endSegmentIndex =
407 chunk.endSegmentIndex < preparedStartByAnalysisIndex.length
408 ? preparedStartByAnalysisIndex[chunk.endSegmentIndex]!
409 : preparedEndByAnalysisIndex[preparedEndByAnalysisIndex.length - 1] ?? 0
410 const consumedEndSegmentIndex =
411 chunk.consumedEndSegmentIndex < preparedStartByAnalysisIndex.length
412 ? preparedStartByAnalysisIndex[chunk.consumedEndSegmentIndex]!
413 : preparedEndByAnalysisIndex[preparedEndByAnalysisIndex.length - 1] ?? 0
414
415 preparedChunks.push({
416 startSegmentIndex,
417 endSegmentIndex,
418 consumedEndSegmentIndex,
419 })
420 }
421 return preparedChunks
422 }
423
424 function prepareInternal(
425 text: string,
426 font: string,
427 includeSegments: boolean,
428 options?: PrepareOptions,
429 ): InternalPreparedText | PreparedTextWithSegments {
430 const analysis = analyzeText(text, getEngineProfile(), options?.whiteSpace)
431 return measureAnalysis(analysis, font, includeSegments)
432 }
433
434 // Diagnostic-only helper used by the browser benchmark harness to separate the
435 // text-analysis and measurement phases without duplicating the prepare logic.
436 export function profilePrepare(text: string, font: string, options?: PrepareOptions): PrepareProfile {
437 const t0 = performance.now()
438 const analysis = analyzeText(text, getEngineProfile(), options?.whiteSpace)
439 const t1 = performance.now()
440 const prepared = measureAnalysis(analysis, font, false) as InternalPreparedText
441 const t2 = performance.now()
442
443 let breakableSegments = 0
444 for (const widths of prepared.breakableWidths) {
445 if (widths !== null) breakableSegments++
446 }
447
448 return {
449 analysisMs: t1 - t0,
450 measureMs: t2 - t1,
451 totalMs: t2 - t0,
452 analysisSegments: analysis.len,
453 preparedSegments: prepared.widths.length,
454 breakableSegments,
455 }
456 }
457
458 // Prepare text for layout. Segments the text, measures each segment via canvas,
459 // and stores the widths for fast relayout at any width. Call once per text block
460 // (e.g. when a comment first appears). The result is width-independent — the
461 // same PreparedText can be laid out at any maxWidth and lineHeight via layout().
462 //
463 // Steps:
464 // 1. Normalize collapsible whitespace (CSS white-space: normal behavior)
465 // 2. Segment via Intl.Segmenter (handles CJK, Thai, etc.)
466 // 3. Merge punctuation into preceding word ("better." as one unit)
467 // 4. Split CJK words into individual graphemes (per-character line breaks)
468 // 5. Measure each segment via canvas measureText, cache by (segment, font)
469 // 6. Pre-measure graphemes of long words (for overflow-wrap: break-word)
470 // 7. Correct emoji canvas inflation (auto-detected per font size)
471 // 8. Optionally compute rich-path bidi metadata for custom renderers
472 export function prepare(text: string, font: string, options?: PrepareOptions): PreparedText {
473 return prepareInternal(text, font, false, options) as PreparedText
474 }
475
476 // Rich variant used by callers that need enough information to render the
477 // laid-out lines themselves.
478 export function prepareWithSegments(text: string, font: string, options?: PrepareOptions): PreparedTextWithSegments {
479 return prepareInternal(text, font, true, options) as PreparedTextWithSegments
480 }
481
482 function getInternalPrepared(prepared: PreparedText): InternalPreparedText {
483 return prepared as InternalPreparedText
484 }
485
486 // Layout prepared text at a given max width and caller-provided lineHeight.
487 // Pure arithmetic on cached widths — no canvas calls, no DOM reads, no string
488 // operations, no allocations.
489 // ~0.0002ms per text block. Call on every resize.
490 //
491 // Line breaking rules (matching CSS white-space: normal + overflow-wrap: break-word):
492 // - Break before any non-space segment that would overflow the line
493 // - Trailing whitespace hangs past the line edge (doesn't trigger breaks)
494 // - Segments wider than maxWidth are broken at grapheme boundaries
495 export function layout(prepared: PreparedText, maxWidth: number, lineHeight: number): LayoutResult {
496 // Keep the resize hot path specialized. `layoutWithLines()` shares the same
497 // break semantics but also tracks line ranges; the extra bookkeeping is too
498 // expensive to pay on every hot-path `layout()` call.
499 const lineCount = countPreparedLines(getInternalPrepared(prepared), maxWidth)
500 return { lineCount, height: lineCount * lineHeight }
501 }
502
503 function getSegmentGraphemes(
504 segmentIndex: number,
505 segments: string[],
506 cache: Map,
507 ): string[] {
508 let graphemes = cache.get(segmentIndex)
509 if (graphemes !== undefined) return graphemes
510
511 graphemes = []
512 const graphemeSegmenter = getSharedGraphemeSegmenter()
513 for (const gs of graphemeSegmenter.segment(segments[segmentIndex]!)) {
514 graphemes.push(gs.segment)
515 }
516 cache.set(segmentIndex, graphemes)
517 return graphemes
518 }
519
520 function getLineTextCache(prepared: PreparedTextWithSegments): Map {
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/layout.ts | sed -n '520,760p'"
Chunk ID: 014465
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 1753
Output:
520 function getLineTextCache(prepared: PreparedTextWithSegments): Map {
521 let cache = sharedLineTextCaches.get(prepared)
522 if (cache !== undefined) return cache
523
524 cache = new Map()
525 sharedLineTextCaches.set(prepared, cache)
526 return cache
527 }
528
529 function lineHasDiscretionaryHyphen(
530 kinds: SegmentBreakKind[],
531 startSegmentIndex: number,
532 startGraphemeIndex: number,
533 endSegmentIndex: number,
534 ): boolean {
535 return (
536 endSegmentIndex > 0 &&
537 kinds[endSegmentIndex - 1] === 'soft-hyphen' &&
538 !(startSegmentIndex === endSegmentIndex && startGraphemeIndex > 0)
539 )
540 }
541
542 function buildLineTextFromRange(
543 segments: string[],
544 kinds: SegmentBreakKind[],
545 cache: Map,
546 startSegmentIndex: number,
547 startGraphemeIndex: number,
548 endSegmentIndex: number,
549 endGraphemeIndex: number,
550 ): string {
551 let text = ''
552 const endsWithDiscretionaryHyphen = lineHasDiscretionaryHyphen(
553 kinds,
554 startSegmentIndex,
555 startGraphemeIndex,
556 endSegmentIndex,
557 )
558
559 for (let i = startSegmentIndex; i < endSegmentIndex; i++) {
560 if (kinds[i] === 'soft-hyphen' || kinds[i] === 'hard-break') continue
561 if (i === startSegmentIndex && startGraphemeIndex > 0) {
562 text += getSegmentGraphemes(i, segments, cache).slice(startGraphemeIndex).join('')
563 } else {
564 text += segments[i]!
565 }
566 }
567
568 if (endGraphemeIndex > 0) {
569 if (endsWithDiscretionaryHyphen) text += '-'
570 text += getSegmentGraphemes(endSegmentIndex, segments, cache).slice(
571 startSegmentIndex === endSegmentIndex ? startGraphemeIndex : 0,
572 endGraphemeIndex,
573 ).join('')
574 } else if (endsWithDiscretionaryHyphen) {
575 text += '-'
576 }
577
578 return text
579 }
580
581 function createLayoutLine(
582 prepared: PreparedTextWithSegments,
583 cache: Map,
584 width: number,
585 startSegmentIndex: number,
586 startGraphemeIndex: number,
587 endSegmentIndex: number,
588 endGraphemeIndex: number,
589 ): LayoutLine {
590 return {
591 text: buildLineTextFromRange(
592 prepared.segments,
593 prepared.kinds,
594 cache,
595 startSegmentIndex,
596 startGraphemeIndex,
597 endSegmentIndex,
598 endGraphemeIndex,
599 ),
600 width,
601 start: {
602 segmentIndex: startSegmentIndex,
603 graphemeIndex: startGraphemeIndex,
604 },
605 end: {
606 segmentIndex: endSegmentIndex,
607 graphemeIndex: endGraphemeIndex,
608 },
609 }
610 }
611
612 function materializeLayoutLine(
613 prepared: PreparedTextWithSegments,
614 cache: Map,
615 line: InternalLayoutLine,
616 ): LayoutLine {
617 return createLayoutLine(
618 prepared,
619 cache,
620 line.width,
621 line.startSegmentIndex,
622 line.startGraphemeIndex,
623 line.endSegmentIndex,
624 line.endGraphemeIndex,
625 )
626 }
627
628 function toLayoutLineRange(line: InternalLayoutLine): LayoutLineRange {
629 return {
630 width: line.width,
631 start: {
632 segmentIndex: line.startSegmentIndex,
633 graphemeIndex: line.startGraphemeIndex,
634 },
635 end: {
636 segmentIndex: line.endSegmentIndex,
637 graphemeIndex: line.endGraphemeIndex,
638 },
639 }
640 }
641
642 function stepLineRange(
643 prepared: PreparedTextWithSegments,
644 start: LayoutCursor,
645 maxWidth: number,
646 ): LayoutLineRange | null {
647 const line = stepPreparedLineRange(prepared, start, maxWidth)
648 if (line === null) return null
649 return toLayoutLineRange(line)
650 }
651
652 function materializeLine(
653 prepared: PreparedTextWithSegments,
654 line: LayoutLineRange,
655 ): LayoutLine {
656 return createLayoutLine(
657 prepared,
658 getLineTextCache(prepared),
659 line.width,
660 line.start.segmentIndex,
661 line.start.graphemeIndex,
662 line.end.segmentIndex,
663 line.end.graphemeIndex,
664 )
665 }
666
667 // Batch low-level line geometry pass. This is the non-materializing counterpart
668 // to layoutWithLines(), useful for shrinkwrap and other aggregate geometry work.
669 export function walkLineRanges(
670 prepared: PreparedTextWithSegments,
671 maxWidth: number,
672 onLine: (line: LayoutLineRange) => void,
673 ): number {
674 if (prepared.widths.length === 0) return 0
675
676 return walkPreparedLines(getInternalPrepared(prepared), maxWidth, line => {
677 onLine(toLayoutLineRange(line))
678 })
679 }
680
681 export function layoutNextLine(
682 prepared: PreparedTextWithSegments,
683 start: LayoutCursor,
684 maxWidth: number,
685 ): LayoutLine | null {
686 const line = stepLineRange(prepared, start, maxWidth)
687 if (line === null) return null
688 return materializeLine(prepared, line)
689 }
690
691 // Rich layout API for callers that want the actual line contents and widths.
692 // Caller still supplies lineHeight at layout time. Mirrors layout()'s break
693 // decisions, but keeps extra per-line bookkeeping so it should stay off the
694 // resize hot path.
695 export function layoutWithLines(prepared: PreparedTextWithSegments, maxWidth: number, lineHeight: number): LayoutLinesResult {
696 const lines: LayoutLine[] = []
697 if (prepared.widths.length === 0) return { lineCount: 0, height: 0, lines }
698
699 const graphemeCache = getLineTextCache(prepared)
700 const lineCount = walkPreparedLines(getInternalPrepared(prepared), maxWidth, line => {
701 lines.push(materializeLayoutLine(prepared, graphemeCache, line))
702 })
703
704 return { lineCount, height: lineCount * lineHeight, lines }
705 }
706
707 export function clearCache(): void {
708 clearAnalysisCaches()
709 sharedGraphemeSegmenter = null
710 sharedLineTextCaches = new WeakMap>()
711 clearMeasurementCaches()
712 }
713
714 export function setLocale(locale?: string): void {
715 setAnalysisLocale(locale)
716 clearCache()
717 }
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/measurement.ts | sed -n '1,260p'"
Chunk ID: bdee1a
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 2257
Output:
1 import { isCJK } from './analysis.js'
2
3 export type SegmentMetrics = {
4 width: number
5 containsCJK: boolean
6 emojiCount?: number
7 graphemeWidths?: number[] | null
8 graphemePrefixWidths?: number[] | null
9 }
10
11 export type EngineProfile = {
12 lineFitEpsilon: number
13 carryCJKAfterClosingQuote: boolean
14 preferPrefixWidthsForBreakableRuns: boolean
15 preferEarlySoftHyphenBreak: boolean
16 }
17
18 let measureContext: CanvasRenderingContext2D | OffscreenCanvasRenderingContext2D | null = null
19 const segmentMetricCaches = new Map>()
20 let cachedEngineProfile: EngineProfile | null = null
21
22 const emojiPresentationRe = /\p{Emoji_Presentation}/u
23 const maybeEmojiRe = /[\p{Emoji_Presentation}\p{Extended_Pictographic}\p{Regional_Indicator}\uFE0F\u20E3]/u
24 let sharedGraphemeSegmenter: Intl.Segmenter | null = null
25 const emojiCorrectionCache = new Map()
26
27 export function getMeasureContext(): CanvasRenderingContext2D | OffscreenCanvasRenderingContext2D {
28 if (measureContext !== null) return measureContext
29
30 if (typeof OffscreenCanvas !== 'undefined') {
31 measureContext = new OffscreenCanvas(1, 1).getContext('2d')!
32 return measureContext
33 }
34
35 if (typeof document !== 'undefined') {
36 measureContext = document.createElement('canvas').getContext('2d')!
37 return measureContext
38 }
39
40 throw new Error('Text measurement requires OffscreenCanvas or a DOM canvas context.')
41 }
42
43 export function getSegmentMetricCache(font: string): Map {
44 let cache = segmentMetricCaches.get(font)
45 if (!cache) {
46 cache = new Map()
47 segmentMetricCaches.set(font, cache)
48 }
49 return cache
50 }
51
52 export function getSegmentMetrics(seg: string, cache: Map): SegmentMetrics {
53 let metrics = cache.get(seg)
54 if (metrics === undefined) {
55 const ctx = getMeasureContext()
56 metrics = {
57 width: ctx.measureText(seg).width,
58 containsCJK: isCJK(seg),
59 }
60 cache.set(seg, metrics)
61 }
62 return metrics
63 }
64
65 export function getEngineProfile(): EngineProfile {
66 if (cachedEngineProfile !== null) return cachedEngineProfile
67
68 if (typeof navigator === 'undefined') {
69 cachedEngineProfile = {
70 lineFitEpsilon: 0.005,
71 carryCJKAfterClosingQuote: false,
72 preferPrefixWidthsForBreakableRuns: false,
73 preferEarlySoftHyphenBreak: false,
74 }
75 return cachedEngineProfile
76 }
77
78 const ua = navigator.userAgent
79 const vendor = navigator.vendor
80 const isSafari =
81 vendor === 'Apple Computer, Inc.' &&
82 ua.includes('Safari/') &&
83 !ua.includes('Chrome/') &&
84 !ua.includes('Chromium/') &&
85 !ua.includes('CriOS/') &&
86 !ua.includes('FxiOS/') &&
87 !ua.includes('EdgiOS/')
88 const isChromium =
89 ua.includes('Chrome/') ||
90 ua.includes('Chromium/') ||
91 ua.includes('CriOS/') ||
92 ua.includes('Edg/')
93
94 cachedEngineProfile = {
95 lineFitEpsilon: isSafari ? 1 / 64 : 0.005,
96 carryCJKAfterClosingQuote: isChromium,
97 preferPrefixWidthsForBreakableRuns: isSafari,
98 preferEarlySoftHyphenBreak: isSafari,
99 }
100 return cachedEngineProfile
101 }
102
103 export function parseFontSize(font: string): number {
104 const m = font.match(/(\d+(?:\.\d+)?)\s*px/)
105 return m ? parseFloat(m[1]!) : 16
106 }
107
108 function getSharedGraphemeSegmenter(): Intl.Segmenter {
109 if (sharedGraphemeSegmenter === null) {
110 sharedGraphemeSegmenter = new Intl.Segmenter(undefined, { granularity: 'grapheme' })
111 }
112 return sharedGraphemeSegmenter
113 }
114
115 function isEmojiGrapheme(g: string): boolean {
116 return emojiPresentationRe.test(g) || g.includes('\uFE0F')
117 }
118
119 export function textMayContainEmoji(text: string): boolean {
120 return maybeEmojiRe.test(text)
121 }
122
123 function getEmojiCorrection(font: string, fontSize: number): number {
124 let correction = emojiCorrectionCache.get(font)
125 if (correction !== undefined) return correction
126
127 const ctx = getMeasureContext()
128 ctx.font = font
129 const canvasW = ctx.measureText('\u{1F600}').width
130 correction = 0
131 if (
132 canvasW > fontSize + 0.5 &&
133 typeof document !== 'undefined' &&
134 document.body !== null
135 ) {
136 const span = document.createElement('span')
137 span.style.font = font
138 span.style.display = 'inline-block'
139 span.style.visibility = 'hidden'
140 span.style.position = 'absolute'
141 span.textContent = '\u{1F600}'
142 document.body.appendChild(span)
143 const domW = span.getBoundingClientRect().width
144 document.body.removeChild(span)
145 if (canvasW - domW > 0.5) {
146 correction = canvasW - domW
147 }
148 }
149 emojiCorrectionCache.set(font, correction)
150 return correction
151 }
152
153 function countEmojiGraphemes(text: string): number {
154 let count = 0
155 const graphemeSegmenter = getSharedGraphemeSegmenter()
156 for (const g of graphemeSegmenter.segment(text)) {
157 if (isEmojiGrapheme(g.segment)) count++
158 }
159 return count
160 }
161
162 function getEmojiCount(seg: string, metrics: SegmentMetrics): number {
163 if (metrics.emojiCount === undefined) {
164 metrics.emojiCount = countEmojiGraphemes(seg)
165 }
166 return metrics.emojiCount
167 }
168
169 export function getCorrectedSegmentWidth(seg: string, metrics: SegmentMetrics, emojiCorrection: number): number {
170 if (emojiCorrection === 0) return metrics.width
171 return metrics.width - getEmojiCount(seg, metrics) * emojiCorrection
172 }
173
174 export function getSegmentGraphemeWidths(
175 seg: string,
176 metrics: SegmentMetrics,
177 cache: Map,
178 emojiCorrection: number,
179 ): number[] | null {
180 if (metrics.graphemeWidths !== undefined) return metrics.graphemeWidths
181
182 const widths: number[] = []
183 const graphemeSegmenter = getSharedGraphemeSegmenter()
184 for (const gs of graphemeSegmenter.segment(seg)) {
185 const graphemeMetrics = getSegmentMetrics(gs.segment, cache)
186 widths.push(getCorrectedSegmentWidth(gs.segment, graphemeMetrics, emojiCorrection))
187 }
188
189 metrics.graphemeWidths = widths.length > 1 ? widths : null
190 return metrics.graphemeWidths
191 }
192
193 export function getSegmentGraphemePrefixWidths(
194 seg: string,
195 metrics: SegmentMetrics,
196 cache: Map,
197 emojiCorrection: number,
198 ): number[] | null {
199 if (metrics.graphemePrefixWidths !== undefined) return metrics.graphemePrefixWidths
200
201 const prefixWidths: number[] = []
202 const graphemeSegmenter = getSharedGraphemeSegmenter()
203 let prefix = ''
204 for (const gs of graphemeSegmenter.segment(seg)) {
205 prefix += gs.segment
206 const prefixMetrics = getSegmentMetrics(prefix, cache)
207 prefixWidths.push(getCorrectedSegmentWidth(prefix, prefixMetrics, emojiCorrection))
208 }
209
210 metrics.graphemePrefixWidths = prefixWidths.length > 1 ? prefixWidths : null
211 return metrics.graphemePrefixWidths
212 }
213
214 export function getFontMeasurementState(font: string, needsEmojiCorrection: boolean): {
215 cache: Map
216 fontSize: number
217 emojiCorrection: number
218 } {
219 const ctx = getMeasureContext()
220 ctx.font = font
221 const cache = getSegmentMetricCache(font)
222 const fontSize = parseFontSize(font)
223 const emojiCorrection = needsEmojiCorrection ? getEmojiCorrection(font, fontSize) : 0
224 return { cache, fontSize, emojiCorrection }
225 }
226
227 export function clearMeasurementCaches(): void {
228 segmentMetricCaches.clear()
229 emojiCorrectionCache.clear()
230 sharedGraphemeSegmenter = null
231 }
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/analysis.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/analysis.ts | sed -n '260,520p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/analysis.ts | sed -n '520,780p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/analysis.ts | sed -n '780,1040p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/analysis.ts | sed -n '1,260p'"
Chunk ID: c81c1e
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 2001
Output:
1 export type WhiteSpaceMode = 'normal' | 'pre-wrap'
2
3 export type SegmentBreakKind =
4 | 'text'
5 | 'space'
6 | 'preserved-space'
7 | 'tab'
8 | 'glue'
9 | 'zero-width-break'
10 | 'soft-hyphen'
11 | 'hard-break'
12
13 type SegmentationPiece = {
14 text: string
15 isWordLike: boolean
16 kind: SegmentBreakKind
17 start: number
18 }
19
20 export type MergedSegmentation = {
21 len: number
22 texts: string[]
23 isWordLike: boolean[]
24 kinds: SegmentBreakKind[]
25 starts: number[]
26 }
27
28 export type AnalysisChunk = {
29 startSegmentIndex: number
30 endSegmentIndex: number
31 consumedEndSegmentIndex: number
32 }
33
34 export type TextAnalysis = { normalized: string, chunks: AnalysisChunk[] } & MergedSegmentation
35
36 export type AnalysisProfile = {
37 carryCJKAfterClosingQuote: boolean
38 }
39
40 const collapsibleWhitespaceRunRe = /[ \t\n\r\f]+/g
41 const needsWhitespaceNormalizationRe = /[\t\n\r\f]| {2,}|^ | $/
42
43 type WhiteSpaceProfile = {
44 mode: WhiteSpaceMode
45 preserveOrdinarySpaces: boolean
46 preserveHardBreaks: boolean
47 }
48
49 function getWhiteSpaceProfile(whiteSpace?: WhiteSpaceMode): WhiteSpaceProfile {
50 const mode = whiteSpace ?? 'normal'
51 return mode === 'pre-wrap'
52 ? { mode, preserveOrdinarySpaces: true, preserveHardBreaks: true }
53 : { mode, preserveOrdinarySpaces: false, preserveHardBreaks: false }
54 }
55
56 export function normalizeWhitespaceNormal(text: string): string {
57 if (!needsWhitespaceNormalizationRe.test(text)) return text
58
59 let normalized = text.replace(collapsibleWhitespaceRunRe, ' ')
60 if (normalized.charCodeAt(0) === 0x20) {
61 normalized = normalized.slice(1)
62 }
63 if (normalized.length > 0 && normalized.charCodeAt(normalized.length - 1) === 0x20) {
64 normalized = normalized.slice(0, -1)
65 }
66 return normalized
67 }
68
69 function normalizeWhitespacePreWrap(text: string): string {
70 if (!/[\r\f]/.test(text)) return text.replace(/\r\n/g, '\n')
71 return text
72 .replace(/\r\n/g, '\n')
73 .replace(/[\r\f]/g, '\n')
74 }
75
76 let sharedWordSegmenter: Intl.Segmenter | null = null
77 let segmenterLocale: string | undefined
78
79 function getSharedWordSegmenter(): Intl.Segmenter {
80 if (sharedWordSegmenter === null) {
81 sharedWordSegmenter = new Intl.Segmenter(segmenterLocale, { granularity: 'word' })
82 }
83 return sharedWordSegmenter
84 }
85
86 export function clearAnalysisCaches(): void {
87 sharedWordSegmenter = null
88 }
89
90 export function setAnalysisLocale(locale?: string): void {
91 const nextLocale = locale && locale.length > 0 ? locale : undefined
92 if (segmenterLocale === nextLocale) return
93 segmenterLocale = nextLocale
94 sharedWordSegmenter = null
95 }
96
97 const arabicScriptRe = /\p{Script=Arabic}/u
98 const combiningMarkRe = /\p{M}/u
99 const decimalDigitRe = /\p{Nd}/u
100
101 function containsArabicScript(text: string): boolean {
102 return arabicScriptRe.test(text)
103 }
104
105 export function isCJK(s: string): boolean {
106 for (const ch of s) {
107 const c = ch.codePointAt(0)!
108 if ((c >= 0x4E00 && c <= 0x9FFF) ||
109 (c >= 0x3400 && c <= 0x4DBF) ||
110 (c >= 0x20000 && c <= 0x2A6DF) ||
111 (c >= 0x2A700 && c <= 0x2B73F) ||
112 (c >= 0x2B740 && c <= 0x2B81F) ||
113 (c >= 0x2B820 && c <= 0x2CEAF) ||
114 (c >= 0x2CEB0 && c <= 0x2EBEF) ||
115 (c >= 0x30000 && c <= 0x3134F) ||
116 (c >= 0xF900 && c <= 0xFAFF) ||
117 (c >= 0x2F800 && c <= 0x2FA1F) ||
118 (c >= 0x3000 && c <= 0x303F) ||
119 (c >= 0x3040 && c <= 0x309F) ||
120 (c >= 0x30A0 && c <= 0x30FF) ||
121 (c >= 0xAC00 && c <= 0xD7AF) ||
122 (c >= 0xFF00 && c <= 0xFFEF)) {
123 return true
124 }
125 }
126 return false
127 }
128
129 export const kinsokuStart = new Set([
130 '\uFF0C',
131 '\uFF0E',
132 '\uFF01',
133 '\uFF1A',
134 '\uFF1B',
135 '\uFF1F',
136 '\u3001',
137 '\u3002',
138 '\u30FB',
139 '\uFF09',
140 '\u3015',
141 '\u3009',
142 '\u300B',
143 '\u300D',
144 '\u300F',
145 '\u3011',
146 '\u3017',
147 '\u3019',
148 '\u301B',
149 '\u30FC',
150 '\u3005',
151 '\u303B',
152 '\u309D',
153 '\u309E',
154 '\u30FD',
155 '\u30FE',
156 ])
157
158 export const kinsokuEnd = new Set([
159 '"',
160 '(', '[', '{',
161 '“', '‘', '«', '‹',
162 '\uFF08',
163 '\u3014',
164 '\u3008',
165 '\u300A',
166 '\u300C',
167 '\u300E',
168 '\u3010',
169 '\u3016',
170 '\u3018',
171 '\u301A',
172 ])
173
174 const forwardStickyGlue = new Set([
175 "'", '’',
176 ])
177
178 export const leftStickyPunctuation = new Set([
179 '.', ',', '!', '?', ':', ';',
180 '\u060C',
181 '\u061B',
182 '\u061F',
183 '\u0964',
184 '\u0965',
185 '\u104A',
186 '\u104B',
187 '\u104C',
188 '\u104D',
189 '\u104F',
190 ')', ']', '}',
191 '%',
192 '"',
193 '”', '’', '»', '›',
194 '…',
195 ])
196
197 const arabicNoSpaceTrailingPunctuation = new Set([
198 ':',
199 '.',
200 '\u060C',
201 '\u061B',
202 ])
203
204 const myanmarMedialGlue = new Set([
205 '\u104F',
206 ])
207
208 const closingQuoteChars = new Set([
209 '”', '’', '»', '›',
210 '\u300D',
211 '\u300F',
212 '\u3011',
213 '\u300B',
214 '\u3009',
215 '\u3015',
216 '\uFF09',
217 ])
218
219 function isLeftStickyPunctuationSegment(segment: string): boolean {
220 if (isEscapedQuoteClusterSegment(segment)) return true
221 let sawPunctuation = false
222 for (const ch of segment) {
223 if (leftStickyPunctuation.has(ch)) {
224 sawPunctuation = true
225 continue
226 }
227 if (sawPunctuation && combiningMarkRe.test(ch)) continue
228 return false
229 }
230 return sawPunctuation
231 }
232
233 function isCJKLineStartProhibitedSegment(segment: string): boolean {
234 for (const ch of segment) {
235 if (!kinsokuStart.has(ch) && !leftStickyPunctuation.has(ch)) return false
236 }
237 return segment.length > 0
238 }
239
240 function isForwardStickyClusterSegment(segment: string): boolean {
241 if (isEscapedQuoteClusterSegment(segment)) return true
242 for (const ch of segment) {
243 if (!kinsokuEnd.has(ch) && !forwardStickyGlue.has(ch) && !combiningMarkRe.test(ch)) return false
244 }
245 return segment.length > 0
246 }
247
248 function isEscapedQuoteClusterSegment(segment: string): boolean {
249 let sawQuote = false
250 for (const ch of segment) {
251 if (ch === '\\' || combiningMarkRe.test(ch)) continue
252 if (kinsokuEnd.has(ch) || leftStickyPunctuation.has(ch) || forwardStickyGlue.has(ch)) {
253 sawQuote = true
254 continue
255 }
256 return false
257 }
258 return sawQuote
259 }
260
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/analysis.ts | sed -n '260,520p'"
Chunk ID: 85bd99
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 2268
Output:
260
261 function splitTrailingForwardStickyCluster(text: string): { head: string, tail: string } | null {
262 const chars = Array.from(text)
263 let splitIndex = chars.length
264
265 while (splitIndex > 0) {
266 const ch = chars[splitIndex - 1]!
267 if (combiningMarkRe.test(ch)) {
268 splitIndex--
269 continue
270 }
271 if (kinsokuEnd.has(ch) || forwardStickyGlue.has(ch)) {
272 splitIndex--
273 continue
274 }
275 break
276 }
277
278 if (splitIndex <= 0 || splitIndex === chars.length) return null
279 return {
280 head: chars.slice(0, splitIndex).join(''),
281 tail: chars.slice(splitIndex).join(''),
282 }
283 }
284
285 function isRepeatedSingleCharRun(segment: string, ch: string): boolean {
286 if (segment.length === 0) return false
287 for (const part of segment) {
288 if (part !== ch) return false
289 }
290 return true
291 }
292
293 function endsWithArabicNoSpacePunctuation(segment: string): boolean {
294 if (!containsArabicScript(segment) || segment.length === 0) return false
295 return arabicNoSpaceTrailingPunctuation.has(segment[segment.length - 1]!)
296 }
297
298 function endsWithMyanmarMedialGlue(segment: string): boolean {
299 if (segment.length === 0) return false
300 return myanmarMedialGlue.has(segment[segment.length - 1]!)
301 }
302
303 function splitLeadingSpaceAndMarks(segment: string): { space: string, marks: string } | null {
304 if (segment.length < 2 || segment[0] !== ' ') return null
305 const marks = segment.slice(1)
306 if (/^\p{M}+$/u.test(marks)) {
307 return { space: ' ', marks }
308 }
309 return null
310 }
311
312 export function endsWithClosingQuote(text: string): boolean {
313 for (let i = text.length - 1; i >= 0; i--) {
314 const ch = text[i]!
315 if (closingQuoteChars.has(ch)) return true
316 if (!leftStickyPunctuation.has(ch)) return false
317 }
318 return false
319 }
320
321 function classifySegmentBreakChar(ch: string, whiteSpaceProfile: WhiteSpaceProfile): SegmentBreakKind {
322 if (whiteSpaceProfile.preserveOrdinarySpaces || whiteSpaceProfile.preserveHardBreaks) {
323 if (ch === ' ') return 'preserved-space'
324 if (ch === '\t') return 'tab'
325 if (whiteSpaceProfile.preserveHardBreaks && ch === '\n') return 'hard-break'
326 }
327 if (ch === ' ') return 'space'
328 if (ch === '\u00A0' || ch === '\u202F' || ch === '\u2060' || ch === '\uFEFF') {
329 return 'glue'
330 }
331 if (ch === '\u200B') return 'zero-width-break'
332 if (ch === '\u00AD') return 'soft-hyphen'
333 return 'text'
334 }
335
336 function splitSegmentByBreakKind(
337 segment: string,
338 isWordLike: boolean,
339 start: number,
340 whiteSpaceProfile: WhiteSpaceProfile,
341 ): SegmentationPiece[] {
342 const pieces: SegmentationPiece[] = []
343 let currentKind: SegmentBreakKind | null = null
344 let currentText = ''
345 let currentStart = start
346 let currentWordLike = false
347 let offset = 0
348
349 for (const ch of segment) {
350 const kind = classifySegmentBreakChar(ch, whiteSpaceProfile)
351 const wordLike = kind === 'text' && isWordLike
352
353 if (currentKind !== null && kind === currentKind && wordLike === currentWordLike) {
354 currentText += ch
355 offset += ch.length
356 continue
357 }
358
359 if (currentKind !== null) {
360 pieces.push({
361 text: currentText,
362 isWordLike: currentWordLike,
363 kind: currentKind,
364 start: currentStart,
365 })
366 }
367
368 currentKind = kind
369 currentText = ch
370 currentStart = start + offset
371 currentWordLike = wordLike
372 offset += ch.length
373 }
374
375 if (currentKind !== null) {
376 pieces.push({
377 text: currentText,
378 isWordLike: currentWordLike,
379 kind: currentKind,
380 start: currentStart,
381 })
382 }
383
384 return pieces
385 }
386
387 function isTextRunBoundary(kind: SegmentBreakKind): boolean {
388 return (
389 kind === 'space' ||
390 kind === 'preserved-space' ||
391 kind === 'zero-width-break' ||
392 kind === 'hard-break'
393 )
394 }
395
396 const urlSchemeSegmentRe = /^[A-Za-z][A-Za-z0-9+.-]*:$/
397
398 function isUrlLikeRunStart(segmentation: MergedSegmentation, index: number): boolean {
399 const text = segmentation.texts[index]!
400 if (text.startsWith('www.')) return true
401 return (
402 urlSchemeSegmentRe.test(text) &&
403 index + 1 < segmentation.len &&
404 segmentation.kinds[index + 1] === 'text' &&
405 segmentation.texts[index + 1] === '//'
406 )
407 }
408
409 function isUrlQueryBoundarySegment(text: string): boolean {
410 return text.includes('?') && (text.includes('://') || text.startsWith('www.'))
411 }
412
413 function mergeUrlLikeRuns(segmentation: MergedSegmentation): MergedSegmentation {
414 const texts = segmentation.texts.slice()
415 const isWordLike = segmentation.isWordLike.slice()
416 const kinds = segmentation.kinds.slice()
417 const starts = segmentation.starts.slice()
418
419 for (let i = 0; i < segmentation.len; i++) {
420 if (kinds[i] !== 'text' || !isUrlLikeRunStart(segmentation, i)) continue
421
422 let j = i + 1
423 while (j < segmentation.len && !isTextRunBoundary(kinds[j]!)) {
424 texts[i] += texts[j]!
425 isWordLike[i] = true
426 const endsQueryPrefix = texts[j]!.includes('?')
427 kinds[j] = 'text'
428 texts[j] = ''
429 j++
430 if (endsQueryPrefix) break
431 }
432 }
433
434 let compactLen = 0
435 for (let read = 0; read < texts.length; read++) {
436 const text = texts[read]!
437 if (text.length === 0) continue
438 if (compactLen !== read) {
439 texts[compactLen] = text
440 isWordLike[compactLen] = isWordLike[read]!
441 kinds[compactLen] = kinds[read]!
442 starts[compactLen] = starts[read]!
443 }
444 compactLen++
445 }
446
447 texts.length = compactLen
448 isWordLike.length = compactLen
449 kinds.length = compactLen
450 starts.length = compactLen
451
452 return {
453 len: compactLen,
454 texts,
455 isWordLike,
456 kinds,
457 starts,
458 }
459 }
460
461 function mergeUrlQueryRuns(segmentation: MergedSegmentation): MergedSegmentation {
462 const texts: string[] = []
463 const isWordLike: boolean[] = []
464 const kinds: SegmentBreakKind[] = []
465 const starts: number[] = []
466
467 for (let i = 0; i < segmentation.len; i++) {
468 const text = segmentation.texts[i]!
469 texts.push(text)
470 isWordLike.push(segmentation.isWordLike[i]!)
471 kinds.push(segmentation.kinds[i]!)
472 starts.push(segmentation.starts[i]!)
473
474 if (!isUrlQueryBoundarySegment(text)) continue
475
476 const nextIndex = i + 1
477 if (
478 nextIndex >= segmentation.len ||
479 isTextRunBoundary(segmentation.kinds[nextIndex]!)
480 ) {
481 continue
482 }
483
484 let queryText = ''
485 const queryStart = segmentation.starts[nextIndex]!
486 let j = nextIndex
487 while (j < segmentation.len && !isTextRunBoundary(segmentation.kinds[j]!)) {
488 queryText += segmentation.texts[j]!
489 j++
490 }
491
492 if (queryText.length > 0) {
493 texts.push(queryText)
494 isWordLike.push(true)
495 kinds.push('text')
496 starts.push(queryStart)
497 i = j - 1
498 }
499 }
500
501 return {
502 len: texts.length,
503 texts,
504 isWordLike,
505 kinds,
506 starts,
507 }
508 }
509
510 const numericJoinerChars = new Set([
511 ':', '-', '/', '×', ',', '.', '+',
512 '\u2013',
513 '\u2014',
514 ])
515
516 const asciiPunctuationChainSegmentRe = /^[A-Za-z0-9_]+[,:;]*$/
517 const asciiPunctuationChainTrailingJoinersRe = /[,:;]+$/
518
519 function segmentContainsDecimalDigit(text: string): boolean {
520 for (const ch of text) {
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/analysis.ts | sed -n '520,780p'"
Chunk ID: de47ec
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 2215
Output:
520 for (const ch of text) {
521 if (decimalDigitRe.test(ch)) return true
522 }
523 return false
524 }
525
526 function isNumericRunSegment(text: string): boolean {
527 if (text.length === 0) return false
528 for (const ch of text) {
529 if (decimalDigitRe.test(ch) || numericJoinerChars.has(ch)) continue
530 return false
531 }
532 return true
533 }
534
535 function mergeNumericRuns(segmentation: MergedSegmentation): MergedSegmentation {
536 const texts: string[] = []
537 const isWordLike: boolean[] = []
538 const kinds: SegmentBreakKind[] = []
539 const starts: number[] = []
540
541 for (let i = 0; i < segmentation.len; i++) {
542 const text = segmentation.texts[i]!
543 const kind = segmentation.kinds[i]!
544
545 if (kind === 'text' && isNumericRunSegment(text) && segmentContainsDecimalDigit(text)) {
546 let mergedText = text
547 let j = i + 1
548 while (
549 j < segmentation.len &&
550 segmentation.kinds[j] === 'text' &&
551 isNumericRunSegment(segmentation.texts[j]!)
552 ) {
553 mergedText += segmentation.texts[j]!
554 j++
555 }
556
557 texts.push(mergedText)
558 isWordLike.push(true)
559 kinds.push('text')
560 starts.push(segmentation.starts[i]!)
561 i = j - 1
562 continue
563 }
564
565 texts.push(text)
566 isWordLike.push(segmentation.isWordLike[i]!)
567 kinds.push(kind)
568 starts.push(segmentation.starts[i]!)
569 }
570
571 return {
572 len: texts.length,
573 texts,
574 isWordLike,
575 kinds,
576 starts,
577 }
578 }
579
580 function mergeAsciiPunctuationChains(segmentation: MergedSegmentation): MergedSegmentation {
581 const texts: string[] = []
582 const isWordLike: boolean[] = []
583 const kinds: SegmentBreakKind[] = []
584 const starts: number[] = []
585
586 for (let i = 0; i < segmentation.len; i++) {
587 const text = segmentation.texts[i]!
588 const kind = segmentation.kinds[i]!
589 const wordLike = segmentation.isWordLike[i]!
590
591 if (kind === 'text' && wordLike && asciiPunctuationChainSegmentRe.test(text)) {
592 let mergedText = text
593 let j = i + 1
594
595 while (
596 asciiPunctuationChainTrailingJoinersRe.test(mergedText) &&
597 j < segmentation.len &&
598 segmentation.kinds[j] === 'text' &&
599 segmentation.isWordLike[j] &&
600 asciiPunctuationChainSegmentRe.test(segmentation.texts[j]!)
601 ) {
602 mergedText += segmentation.texts[j]!
603 j++
604 }
605
606 texts.push(mergedText)
607 isWordLike.push(true)
608 kinds.push('text')
609 starts.push(segmentation.starts[i]!)
610 i = j - 1
611 continue
612 }
613
614 texts.push(text)
615 isWordLike.push(wordLike)
616 kinds.push(kind)
617 starts.push(segmentation.starts[i]!)
618 }
619
620 return {
621 len: texts.length,
622 texts,
623 isWordLike,
624 kinds,
625 starts,
626 }
627 }
628
629 function splitHyphenatedNumericRuns(segmentation: MergedSegmentation): MergedSegmentation {
630 const texts: string[] = []
631 const isWordLike: boolean[] = []
632 const kinds: SegmentBreakKind[] = []
633 const starts: number[] = []
634
635 for (let i = 0; i < segmentation.len; i++) {
636 const text = segmentation.texts[i]!
637 if (segmentation.kinds[i] === 'text' && text.includes('-')) {
638 const parts = text.split('-')
639 let shouldSplit = parts.length > 1
640 for (let j = 0; j < parts.length; j++) {
641 const part = parts[j]!
642 if (!shouldSplit) break
643 if (
644 part.length === 0 ||
645 !segmentContainsDecimalDigit(part) ||
646 !isNumericRunSegment(part)
647 ) {
648 shouldSplit = false
649 }
650 }
651
652 if (shouldSplit) {
653 let offset = 0
654 for (let j = 0; j < parts.length; j++) {
655 const part = parts[j]!
656 const splitText = j < parts.length - 1 ? `${part}-` : part
657 texts.push(splitText)
658 isWordLike.push(true)
659 kinds.push('text')
660 starts.push(segmentation.starts[i]! + offset)
661 offset += splitText.length
662 }
663 continue
664 }
665 }
666
667 texts.push(text)
668 isWordLike.push(segmentation.isWordLike[i]!)
669 kinds.push(segmentation.kinds[i]!)
670 starts.push(segmentation.starts[i]!)
671 }
672
673 return {
674 len: texts.length,
675 texts,
676 isWordLike,
677 kinds,
678 starts,
679 }
680 }
681
682 function mergeGlueConnectedTextRuns(segmentation: MergedSegmentation): MergedSegmentation {
683 const texts: string[] = []
684 const isWordLike: boolean[] = []
685 const kinds: SegmentBreakKind[] = []
686 const starts: number[] = []
687
688 let read = 0
689 while (read < segmentation.len) {
690 let text = segmentation.texts[read]!
691 let wordLike = segmentation.isWordLike[read]!
692 let kind = segmentation.kinds[read]!
693 let start = segmentation.starts[read]!
694
695 if (kind === 'glue') {
696 let glueText = text
697 const glueStart = start
698 read++
699 while (read < segmentation.len && segmentation.kinds[read] === 'glue') {
700 glueText += segmentation.texts[read]!
701 read++
702 }
703
704 if (read < segmentation.len && segmentation.kinds[read] === 'text') {
705 text = glueText + segmentation.texts[read]!
706 wordLike = segmentation.isWordLike[read]!
707 kind = 'text'
708 start = glueStart
709 read++
710 } else {
711 texts.push(glueText)
712 isWordLike.push(false)
713 kinds.push('glue')
714 starts.push(glueStart)
715 continue
716 }
717 } else {
718 read++
719 }
720
721 if (kind === 'text') {
722 while (read < segmentation.len && segmentation.kinds[read] === 'glue') {
723 let glueText = ''
724 while (read < segmentation.len && segmentation.kinds[read] === 'glue') {
725 glueText += segmentation.texts[read]!
726 read++
727 }
728
729 if (read < segmentation.len && segmentation.kinds[read] === 'text') {
730 text += glueText + segmentation.texts[read]!
731 wordLike = wordLike || segmentation.isWordLike[read]!
732 read++
733 continue
734 }
735
736 text += glueText
737 }
738 }
739
740 texts.push(text)
741 isWordLike.push(wordLike)
742 kinds.push(kind)
743 starts.push(start)
744 }
745
746 return {
747 len: texts.length,
748 texts,
749 isWordLike,
750 kinds,
751 starts,
752 }
753 }
754
755 function carryTrailingForwardStickyAcrossCJKBoundary(segmentation: MergedSegmentation): MergedSegmentation {
756 const texts = segmentation.texts.slice()
757 const isWordLike = segmentation.isWordLike.slice()
758 const kinds = segmentation.kinds.slice()
759 const starts = segmentation.starts.slice()
760
761 for (let i = 0; i < texts.length - 1; i++) {
762 if (kinds[i] !== 'text' || kinds[i + 1] !== 'text') continue
763 if (!isCJK(texts[i]!) || !isCJK(texts[i + 1]!)) continue
764
765 const split = splitTrailingForwardStickyCluster(texts[i]!)
766 if (split === null) continue
767
768 texts[i] = split.head
769 texts[i + 1] = split.tail + texts[i + 1]!
770 starts[i + 1] = starts[i]! + split.head.length
771 }
772
773 return {
774 len: texts.length,
775 texts,
776 isWordLike,
777 kinds,
778 starts,
779 }
780 }
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/analysis.ts | sed -n '780,1040p'"
Chunk ID: 6412e5
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 2237
Output:
780 }
781
782
783 function buildMergedSegmentation(
784 normalized: string,
785 profile: AnalysisProfile,
786 whiteSpaceProfile: WhiteSpaceProfile,
787 ): MergedSegmentation {
788 const wordSegmenter = getSharedWordSegmenter()
789 let mergedLen = 0
790 const mergedTexts: string[] = []
791 const mergedWordLike: boolean[] = []
792 const mergedKinds: SegmentBreakKind[] = []
793 const mergedStarts: number[] = []
794
795 for (const s of wordSegmenter.segment(normalized)) {
796 for (const piece of splitSegmentByBreakKind(s.segment, s.isWordLike ?? false, s.index, whiteSpaceProfile)) {
797 const isText = piece.kind === 'text'
798
799 if (
800 profile.carryCJKAfterClosingQuote &&
801 isText &&
802 mergedLen > 0 &&
803 mergedKinds[mergedLen - 1] === 'text' &&
804 isCJK(piece.text) &&
805 isCJK(mergedTexts[mergedLen - 1]!) &&
806 endsWithClosingQuote(mergedTexts[mergedLen - 1]!)
807 ) {
808 mergedTexts[mergedLen - 1] += piece.text
809 mergedWordLike[mergedLen - 1] = mergedWordLike[mergedLen - 1]! || piece.isWordLike
810 } else if (
811 isText &&
812 mergedLen > 0 &&
813 mergedKinds[mergedLen - 1] === 'text' &&
814 isCJKLineStartProhibitedSegment(piece.text) &&
815 isCJK(mergedTexts[mergedLen - 1]!)
816 ) {
817 mergedTexts[mergedLen - 1] += piece.text
818 mergedWordLike[mergedLen - 1] = mergedWordLike[mergedLen - 1]! || piece.isWordLike
819 } else if (
820 isText &&
821 mergedLen > 0 &&
822 mergedKinds[mergedLen - 1] === 'text' &&
823 endsWithMyanmarMedialGlue(mergedTexts[mergedLen - 1]!)
824 ) {
825 mergedTexts[mergedLen - 1] += piece.text
826 mergedWordLike[mergedLen - 1] = mergedWordLike[mergedLen - 1]! || piece.isWordLike
827 } else if (
828 isText &&
829 mergedLen > 0 &&
830 mergedKinds[mergedLen - 1] === 'text' &&
831 piece.isWordLike &&
832 containsArabicScript(piece.text) &&
833 endsWithArabicNoSpacePunctuation(mergedTexts[mergedLen - 1]!)
834 ) {
835 mergedTexts[mergedLen - 1] += piece.text
836 mergedWordLike[mergedLen - 1] = true
837 } else if (
838 isText &&
839 !piece.isWordLike &&
840 mergedLen > 0 &&
841 mergedKinds[mergedLen - 1] === 'text' &&
842 piece.text.length === 1 &&
843 piece.text !== '-' &&
844 piece.text !== '—' &&
845 isRepeatedSingleCharRun(mergedTexts[mergedLen - 1]!, piece.text)
846 ) {
847 mergedTexts[mergedLen - 1] += piece.text
848 } else if (
849 isText &&
850 !piece.isWordLike &&
851 mergedLen > 0 &&
852 mergedKinds[mergedLen - 1] === 'text' &&
853 (
854 isLeftStickyPunctuationSegment(piece.text) ||
855 (piece.text === '-' && mergedWordLike[mergedLen - 1]!)
856 )
857 ) {
858 mergedTexts[mergedLen - 1] += piece.text
859 } else {
860 mergedTexts[mergedLen] = piece.text
861 mergedWordLike[mergedLen] = piece.isWordLike
862 mergedKinds[mergedLen] = piece.kind
863 mergedStarts[mergedLen] = piece.start
864 mergedLen++
865 }
866 }
867 }
868
869 for (let i = 1; i < mergedLen; i++) {
870 if (
871 mergedKinds[i] === 'text' &&
872 !mergedWordLike[i]! &&
873 isEscapedQuoteClusterSegment(mergedTexts[i]!) &&
874 mergedKinds[i - 1] === 'text'
875 ) {
876 mergedTexts[i - 1] += mergedTexts[i]!
877 mergedWordLike[i - 1] = mergedWordLike[i - 1]! || mergedWordLike[i]!
878 mergedTexts[i] = ''
879 }
880 }
881
882 for (let i = mergedLen - 2; i >= 0; i--) {
883 if (mergedKinds[i] === 'text' && !mergedWordLike[i]! && isForwardStickyClusterSegment(mergedTexts[i]!)) {
884 let j = i + 1
885 while (j < mergedLen && mergedTexts[j] === '') j++
886 if (j < mergedLen && mergedKinds[j] === 'text') {
887 mergedTexts[j] = mergedTexts[i]! + mergedTexts[j]!
888 mergedStarts[j] = mergedStarts[i]!
889 mergedTexts[i] = ''
890 }
891 }
892 }
893
894 let compactLen = 0
895 for (let read = 0; read < mergedLen; read++) {
896 const text = mergedTexts[read]!
897 if (text.length === 0) continue
898 if (compactLen !== read) {
899 mergedTexts[compactLen] = text
900 mergedWordLike[compactLen] = mergedWordLike[read]!
901 mergedKinds[compactLen] = mergedKinds[read]!
902 mergedStarts[compactLen] = mergedStarts[read]!
903 }
904 compactLen++
905 }
906
907 mergedTexts.length = compactLen
908 mergedWordLike.length = compactLen
909 mergedKinds.length = compactLen
910 mergedStarts.length = compactLen
911
912 const compacted = mergeGlueConnectedTextRuns({
913 len: compactLen,
914 texts: mergedTexts,
915 isWordLike: mergedWordLike,
916 kinds: mergedKinds,
917 starts: mergedStarts,
918 })
919 const withMergedUrls = carryTrailingForwardStickyAcrossCJKBoundary(
920 mergeAsciiPunctuationChains(
921 splitHyphenatedNumericRuns(mergeNumericRuns(mergeUrlQueryRuns(mergeUrlLikeRuns(compacted)))),
922 ),
923 )
924
925 for (let i = 0; i < withMergedUrls.len - 1; i++) {
926 const split = splitLeadingSpaceAndMarks(withMergedUrls.texts[i]!)
927 if (split === null) continue
928 if (
929 (withMergedUrls.kinds[i] !== 'space' && withMergedUrls.kinds[i] !== 'preserved-space') ||
930 withMergedUrls.kinds[i + 1] !== 'text' ||
931 !containsArabicScript(withMergedUrls.texts[i + 1]!)
932 ) {
933 continue
934 }
935
936 withMergedUrls.texts[i] = split.space
937 withMergedUrls.isWordLike[i] = false
938 withMergedUrls.kinds[i] = withMergedUrls.kinds[i] === 'preserved-space' ? 'preserved-space' : 'space'
939 withMergedUrls.texts[i + 1] = split.marks + withMergedUrls.texts[i + 1]!
940 withMergedUrls.starts[i + 1] = withMergedUrls.starts[i]! + split.space.length
941 }
942
943 return withMergedUrls
944 }
945
946 function compileAnalysisChunks(segmentation: MergedSegmentation, whiteSpaceProfile: WhiteSpaceProfile): AnalysisChunk[] {
947 if (segmentation.len === 0) return []
948 if (!whiteSpaceProfile.preserveHardBreaks) {
949 return [{
950 startSegmentIndex: 0,
951 endSegmentIndex: segmentation.len,
952 consumedEndSegmentIndex: segmentation.len,
953 }]
954 }
955
956 const chunks: AnalysisChunk[] = []
957 let startSegmentIndex = 0
958
959 for (let i = 0; i < segmentation.len; i++) {
960 if (segmentation.kinds[i] !== 'hard-break') continue
961
962 chunks.push({
963 startSegmentIndex,
964 endSegmentIndex: i,
965 consumedEndSegmentIndex: i + 1,
966 })
967 startSegmentIndex = i + 1
968 }
969
970 if (startSegmentIndex < segmentation.len) {
971 chunks.push({
972 startSegmentIndex,
973 endSegmentIndex: segmentation.len,
974 consumedEndSegmentIndex: segmentation.len,
975 })
976 }
977
978 return chunks
979 }
980
981 export function analyzeText(
982 text: string,
983 profile: AnalysisProfile,
984 whiteSpace: WhiteSpaceMode = 'normal',
985 ): TextAnalysis {
986 const whiteSpaceProfile = getWhiteSpaceProfile(whiteSpace)
987 const normalized = whiteSpaceProfile.mode === 'pre-wrap'
988 ? normalizeWhitespacePreWrap(text)
989 : normalizeWhitespaceNormal(text)
990 if (normalized.length === 0) {
991 return {
992 normalized,
993 chunks: [],
994 len: 0,
995 texts: [],
996 isWordLike: [],
997 kinds: [],
998 starts: [],
999 }
1000 }
1001 const segmentation = buildMergedSegmentation(normalized, profile, whiteSpaceProfile)
1002 return {
1003 normalized,
1004 chunks: compileAnalysisChunks(segmentation, whiteSpaceProfile),
1005 ...segmentation,
1006 }
1007 }
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/line-break.ts | sed -n '1,260p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/line-break.ts | sed -n '260,520p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/line-break.ts | sed -n '520,780p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/line-break.ts | sed -n '780,1084p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/line-break.ts | sed -n '1,260p'"
Chunk ID: 8dc9b6
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 2361
Output:
1 import type { SegmentBreakKind } from './analysis.js'
2 import { getEngineProfile } from './measurement.js'
3
4 export type LineBreakCursor = {
5 segmentIndex: number
6 graphemeIndex: number
7 }
8
9 export type PreparedLineBreakData = {
10 widths: number[]
11 lineEndFitAdvances: number[]
12 lineEndPaintAdvances: number[]
13 kinds: SegmentBreakKind[]
14 simpleLineWalkFastPath: boolean
15 breakableWidths: (number[] | null)[]
16 breakablePrefixWidths: (number[] | null)[]
17 discretionaryHyphenWidth: number
18 tabStopAdvance: number
19 chunks: {
20 startSegmentIndex: number
21 endSegmentIndex: number
22 consumedEndSegmentIndex: number
23 }[]
24 }
25
26 export type InternalLayoutLine = {
27 startSegmentIndex: number
28 startGraphemeIndex: number
29 endSegmentIndex: number
30 endGraphemeIndex: number
31 width: number
32 }
33
34 function canBreakAfter(kind: SegmentBreakKind): boolean {
35 return (
36 kind === 'space' ||
37 kind === 'preserved-space' ||
38 kind === 'tab' ||
39 kind === 'zero-width-break' ||
40 kind === 'soft-hyphen'
41 )
42 }
43
44 function isSimpleCollapsibleSpace(kind: SegmentBreakKind): boolean {
45 return kind === 'space'
46 }
47
48 function getTabAdvance(lineWidth: number, tabStopAdvance: number): number {
49 if (tabStopAdvance <= 0) return 0
50
51 const remainder = lineWidth % tabStopAdvance
52 if (Math.abs(remainder) <= 1e-6) return tabStopAdvance
53 return tabStopAdvance - remainder
54 }
55
56 function getBreakableAdvance(
57 graphemeWidths: number[],
58 graphemePrefixWidths: number[] | null,
59 graphemeIndex: number,
60 preferPrefixWidths: boolean,
61 ): number {
62 if (!preferPrefixWidths || graphemePrefixWidths === null) {
63 return graphemeWidths[graphemeIndex]!
64 }
65 return graphemePrefixWidths[graphemeIndex]! - (graphemeIndex > 0 ? graphemePrefixWidths[graphemeIndex - 1]! : 0)
66 }
67
68 function fitSoftHyphenBreak(
69 graphemeWidths: number[],
70 initialWidth: number,
71 maxWidth: number,
72 lineFitEpsilon: number,
73 discretionaryHyphenWidth: number,
74 cumulativeWidths: boolean,
75 ): { fitCount: number, fittedWidth: number } {
76 let fitCount = 0
77 let fittedWidth = initialWidth
78
79 while (fitCount < graphemeWidths.length) {
80 const nextWidth = cumulativeWidths
81 ? initialWidth + graphemeWidths[fitCount]!
82 : fittedWidth + graphemeWidths[fitCount]!
83 const nextLineWidth = fitCount + 1 < graphemeWidths.length
84 ? nextWidth + discretionaryHyphenWidth
85 : nextWidth
86 if (nextLineWidth > maxWidth + lineFitEpsilon) break
87 fittedWidth = nextWidth
88 fitCount++
89 }
90
91 return { fitCount, fittedWidth }
92 }
93
94 function findChunkIndexForStart(prepared: PreparedLineBreakData, segmentIndex: number): number {
95 for (let i = 0; i < prepared.chunks.length; i++) {
96 const chunk = prepared.chunks[i]!
97 if (segmentIndex < chunk.consumedEndSegmentIndex) return i
98 }
99 return -1
100 }
101
102 export function normalizeLineStart(
103 prepared: PreparedLineBreakData,
104 start: LineBreakCursor,
105 ): LineBreakCursor | null {
106 let segmentIndex = start.segmentIndex
107 const graphemeIndex = start.graphemeIndex
108
109 if (segmentIndex >= prepared.widths.length) return null
110 if (graphemeIndex > 0) return start
111
112 const chunkIndex = findChunkIndexForStart(prepared, segmentIndex)
113 if (chunkIndex < 0) return null
114
115 const chunk = prepared.chunks[chunkIndex]!
116 if (chunk.startSegmentIndex === chunk.endSegmentIndex && segmentIndex === chunk.startSegmentIndex) {
117 return { segmentIndex, graphemeIndex: 0 }
118 }
119
120 if (segmentIndex < chunk.startSegmentIndex) segmentIndex = chunk.startSegmentIndex
121 while (segmentIndex < chunk.endSegmentIndex) {
122 const kind = prepared.kinds[segmentIndex]!
123 if (kind !== 'space' && kind !== 'zero-width-break' && kind !== 'soft-hyphen') {
124 return { segmentIndex, graphemeIndex: 0 }
125 }
126 segmentIndex++
127 }
128
129 if (chunk.consumedEndSegmentIndex >= prepared.widths.length) return null
130 return { segmentIndex: chunk.consumedEndSegmentIndex, graphemeIndex: 0 }
131 }
132
133 export function countPreparedLines(prepared: PreparedLineBreakData, maxWidth: number): number {
134 if (prepared.simpleLineWalkFastPath) {
135 return countPreparedLinesSimple(prepared, maxWidth)
136 }
137 return walkPreparedLines(prepared, maxWidth)
138 }
139
140 function countPreparedLinesSimple(prepared: PreparedLineBreakData, maxWidth: number): number {
141 const { widths, kinds, breakableWidths, breakablePrefixWidths } = prepared
142 if (widths.length === 0) return 0
143
144 const engineProfile = getEngineProfile()
145 const lineFitEpsilon = engineProfile.lineFitEpsilon
146
147 let lineCount = 0
148 let lineW = 0
149 let hasContent = false
150
151 function placeOnFreshLine(segmentIndex: number): void {
152 const w = widths[segmentIndex]!
153 if (w > maxWidth && breakableWidths[segmentIndex] !== null) {
154 const gWidths = breakableWidths[segmentIndex]!
155 const gPrefixWidths = breakablePrefixWidths[segmentIndex] ?? null
156 lineW = 0
157 for (let g = 0; g < gWidths.length; g++) {
158 const gw = getBreakableAdvance(
159 gWidths,
160 gPrefixWidths,
161 g,
162 engineProfile.preferPrefixWidthsForBreakableRuns,
163 )
164 if (lineW > 0 && lineW + gw > maxWidth + lineFitEpsilon) {
165 lineCount++
166 lineW = gw
167 } else {
168 if (lineW === 0) lineCount++
169 lineW += gw
170 }
171 }
172 } else {
173 lineW = w
174 lineCount++
175 }
176 hasContent = true
177 }
178
179 for (let i = 0; i < widths.length; i++) {
180 const w = widths[i]!
181 const kind = kinds[i]!
182
183 if (!hasContent) {
184 placeOnFreshLine(i)
185 continue
186 }
187
188 const newW = lineW + w
189 if (newW > maxWidth + lineFitEpsilon) {
190 if (isSimpleCollapsibleSpace(kind)) continue
191 lineW = 0
192 hasContent = false
193 placeOnFreshLine(i)
194 continue
195 }
196
197 lineW = newW
198 }
199
200 if (!hasContent) return lineCount + 1
201 return lineCount
202 }
203
204 function walkPreparedLinesSimple(
205 prepared: PreparedLineBreakData,
206 maxWidth: number,
207 onLine?: (line: InternalLayoutLine) => void,
208 ): number {
209 const { widths, kinds, breakableWidths, breakablePrefixWidths } = prepared
210 if (widths.length === 0) return 0
211
212 const engineProfile = getEngineProfile()
213 const lineFitEpsilon = engineProfile.lineFitEpsilon
214
215 let lineCount = 0
216 let lineW = 0
217 let hasContent = false
218 let lineStartSegmentIndex = 0
219 let lineStartGraphemeIndex = 0
220 let lineEndSegmentIndex = 0
221 let lineEndGraphemeIndex = 0
222 let pendingBreakSegmentIndex = -1
223 let pendingBreakPaintWidth = 0
224
225 function clearPendingBreak(): void {
226 pendingBreakSegmentIndex = -1
227 pendingBreakPaintWidth = 0
228 }
229
230 function emitCurrentLine(
231 endSegmentIndex = lineEndSegmentIndex,
232 endGraphemeIndex = lineEndGraphemeIndex,
233 width = lineW,
234 ): void {
235 lineCount++
236 onLine?.({
237 startSegmentIndex: lineStartSegmentIndex,
238 startGraphemeIndex: lineStartGraphemeIndex,
239 endSegmentIndex,
240 endGraphemeIndex,
241 width,
242 })
243 lineW = 0
244 hasContent = false
245 clearPendingBreak()
246 }
247
248 function startLineAtSegment(segmentIndex: number, width: number): void {
249 hasContent = true
250 lineStartSegmentIndex = segmentIndex
251 lineStartGraphemeIndex = 0
252 lineEndSegmentIndex = segmentIndex + 1
253 lineEndGraphemeIndex = 0
254 lineW = width
255 }
256
257 function startLineAtGrapheme(segmentIndex: number, graphemeIndex: number, width: number): void {
258 hasContent = true
259 lineStartSegmentIndex = segmentIndex
260 lineStartGraphemeIndex = graphemeIndex
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/line-break.ts | sed -n '260,520p'"
Chunk ID: 43e98f
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 2411
Output:
260 lineStartGraphemeIndex = graphemeIndex
261 lineEndSegmentIndex = segmentIndex
262 lineEndGraphemeIndex = graphemeIndex + 1
263 lineW = width
264 }
265
266 function appendWholeSegment(segmentIndex: number, width: number): void {
267 if (!hasContent) {
268 startLineAtSegment(segmentIndex, width)
269 return
270 }
271 lineW += width
272 lineEndSegmentIndex = segmentIndex + 1
273 lineEndGraphemeIndex = 0
274 }
275
276 function updatePendingBreak(segmentIndex: number, segmentWidth: number): void {
277 if (!canBreakAfter(kinds[segmentIndex]!)) return
278 pendingBreakSegmentIndex = segmentIndex + 1
279 pendingBreakPaintWidth = lineW - segmentWidth
280 }
281
282 function appendBreakableSegment(segmentIndex: number): void {
283 appendBreakableSegmentFrom(segmentIndex, 0)
284 }
285
286 function appendBreakableSegmentFrom(segmentIndex: number, startGraphemeIndex: number): void {
287 const gWidths = breakableWidths[segmentIndex]!
288 const gPrefixWidths = breakablePrefixWidths[segmentIndex] ?? null
289 for (let g = startGraphemeIndex; g < gWidths.length; g++) {
290 const gw = getBreakableAdvance(
291 gWidths,
292 gPrefixWidths,
293 g,
294 engineProfile.preferPrefixWidthsForBreakableRuns,
295 )
296
297 if (!hasContent) {
298 startLineAtGrapheme(segmentIndex, g, gw)
299 continue
300 }
301
302 if (lineW + gw > maxWidth + lineFitEpsilon) {
303 emitCurrentLine()
304 startLineAtGrapheme(segmentIndex, g, gw)
305 } else {
306 lineW += gw
307 lineEndSegmentIndex = segmentIndex
308 lineEndGraphemeIndex = g + 1
309 }
310 }
311
312 if (hasContent && lineEndSegmentIndex === segmentIndex && lineEndGraphemeIndex === gWidths.length) {
313 lineEndSegmentIndex = segmentIndex + 1
314 lineEndGraphemeIndex = 0
315 }
316 }
317
318 let i = 0
319 while (i < widths.length) {
320 const w = widths[i]!
321 const kind = kinds[i]!
322
323 if (!hasContent) {
324 if (w > maxWidth && breakableWidths[i] !== null) {
325 appendBreakableSegment(i)
326 } else {
327 startLineAtSegment(i, w)
328 }
329 updatePendingBreak(i, w)
330 i++
331 continue
332 }
333
334 const newW = lineW + w
335 if (newW > maxWidth + lineFitEpsilon) {
336 if (canBreakAfter(kind)) {
337 appendWholeSegment(i, w)
338 emitCurrentLine(i + 1, 0, lineW - w)
339 i++
340 continue
341 }
342
343 if (pendingBreakSegmentIndex >= 0) {
344 if (
345 lineEndSegmentIndex > pendingBreakSegmentIndex ||
346 (lineEndSegmentIndex === pendingBreakSegmentIndex && lineEndGraphemeIndex > 0)
347 ) {
348 emitCurrentLine()
349 continue
350 }
351 emitCurrentLine(pendingBreakSegmentIndex, 0, pendingBreakPaintWidth)
352 continue
353 }
354
355 if (w > maxWidth && breakableWidths[i] !== null) {
356 emitCurrentLine()
357 appendBreakableSegment(i)
358 i++
359 continue
360 }
361
362 emitCurrentLine()
363 continue
364 }
365
366 appendWholeSegment(i, w)
367 updatePendingBreak(i, w)
368 i++
369 }
370
371 if (hasContent) emitCurrentLine()
372 return lineCount
373 }
374
375 export function walkPreparedLines(
376 prepared: PreparedLineBreakData,
377 maxWidth: number,
378 onLine?: (line: InternalLayoutLine) => void,
379 ): number {
380 if (prepared.simpleLineWalkFastPath) {
381 return walkPreparedLinesSimple(prepared, maxWidth, onLine)
382 }
383
384 const {
385 widths,
386 lineEndFitAdvances,
387 lineEndPaintAdvances,
388 kinds,
389 breakableWidths,
390 breakablePrefixWidths,
391 discretionaryHyphenWidth,
392 tabStopAdvance,
393 chunks,
394 } = prepared
395 if (widths.length === 0 || chunks.length === 0) return 0
396
397 const engineProfile = getEngineProfile()
398 const lineFitEpsilon = engineProfile.lineFitEpsilon
399
400 let lineCount = 0
401 let lineW = 0
402 let hasContent = false
403 let lineStartSegmentIndex = 0
404 let lineStartGraphemeIndex = 0
405 let lineEndSegmentIndex = 0
406 let lineEndGraphemeIndex = 0
407 let pendingBreakSegmentIndex = -1
408 let pendingBreakFitWidth = 0
409 let pendingBreakPaintWidth = 0
410 let pendingBreakKind: SegmentBreakKind | null = null
411
412 function clearPendingBreak(): void {
413 pendingBreakSegmentIndex = -1
414 pendingBreakFitWidth = 0
415 pendingBreakPaintWidth = 0
416 pendingBreakKind = null
417 }
418
419 function emitCurrentLine(
420 endSegmentIndex = lineEndSegmentIndex,
421 endGraphemeIndex = lineEndGraphemeIndex,
422 width = lineW,
423 ): void {
424 lineCount++
425 onLine?.({
426 startSegmentIndex: lineStartSegmentIndex,
427 startGraphemeIndex: lineStartGraphemeIndex,
428 endSegmentIndex,
429 endGraphemeIndex,
430 width,
431 })
432 lineW = 0
433 hasContent = false
434 clearPendingBreak()
435 }
436
437 function startLineAtSegment(segmentIndex: number, width: number): void {
438 hasContent = true
439 lineStartSegmentIndex = segmentIndex
440 lineStartGraphemeIndex = 0
441 lineEndSegmentIndex = segmentIndex + 1
442 lineEndGraphemeIndex = 0
443 lineW = width
444 }
445
446 function startLineAtGrapheme(segmentIndex: number, graphemeIndex: number, width: number): void {
447 hasContent = true
448 lineStartSegmentIndex = segmentIndex
449 lineStartGraphemeIndex = graphemeIndex
450 lineEndSegmentIndex = segmentIndex
451 lineEndGraphemeIndex = graphemeIndex + 1
452 lineW = width
453 }
454
455 function appendWholeSegment(segmentIndex: number, width: number): void {
456 if (!hasContent) {
457 startLineAtSegment(segmentIndex, width)
458 return
459 }
460 lineW += width
461 lineEndSegmentIndex = segmentIndex + 1
462 lineEndGraphemeIndex = 0
463 }
464
465 function updatePendingBreakForWholeSegment(segmentIndex: number, segmentWidth: number): void {
466 if (!canBreakAfter(kinds[segmentIndex]!)) return
467 const fitAdvance = kinds[segmentIndex] === 'tab' ? 0 : lineEndFitAdvances[segmentIndex]!
468 const paintAdvance = kinds[segmentIndex] === 'tab' ? segmentWidth : lineEndPaintAdvances[segmentIndex]!
469 pendingBreakSegmentIndex = segmentIndex + 1
470 pendingBreakFitWidth = lineW - segmentWidth + fitAdvance
471 pendingBreakPaintWidth = lineW - segmentWidth + paintAdvance
472 pendingBreakKind = kinds[segmentIndex]!
473 }
474
475 function appendBreakableSegment(segmentIndex: number): void {
476 appendBreakableSegmentFrom(segmentIndex, 0)
477 }
478
479 function appendBreakableSegmentFrom(segmentIndex: number, startGraphemeIndex: number): void {
480 const gWidths = breakableWidths[segmentIndex]!
481 const gPrefixWidths = breakablePrefixWidths[segmentIndex] ?? null
482 for (let g = startGraphemeIndex; g < gWidths.length; g++) {
483 const gw = getBreakableAdvance(
484 gWidths,
485 gPrefixWidths,
486 g,
487 engineProfile.preferPrefixWidthsForBreakableRuns,
488 )
489
490 if (!hasContent) {
491 startLineAtGrapheme(segmentIndex, g, gw)
492 continue
493 }
494
495 if (lineW + gw > maxWidth + lineFitEpsilon) {
496 emitCurrentLine()
497 startLineAtGrapheme(segmentIndex, g, gw)
498 } else {
499 lineW += gw
500 lineEndSegmentIndex = segmentIndex
501 lineEndGraphemeIndex = g + 1
502 }
503 }
504
505 if (hasContent && lineEndSegmentIndex === segmentIndex && lineEndGraphemeIndex === gWidths.length) {
506 lineEndSegmentIndex = segmentIndex + 1
507 lineEndGraphemeIndex = 0
508 }
509 }
510
511 function continueSoftHyphenBreakableSegment(segmentIndex: number): boolean {
512 if (pendingBreakKind !== 'soft-hyphen') return false
513 const gWidths = breakableWidths[segmentIndex]!
514 if (gWidths === null) return false
515 const fitWidths = engineProfile.preferPrefixWidthsForBreakableRuns
516 ? breakablePrefixWidths[segmentIndex] ?? gWidths
517 : gWidths
518 const usesPrefixWidths = fitWidths !== gWidths
519 const { fitCount, fittedWidth } = fitSoftHyphenBreak(
520 fitWidths,
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/line-break.ts | sed -n '520,780p'"
Chunk ID: eb19ad
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 2457
Output:
520 fitWidths,
521 lineW,
522 maxWidth,
523 lineFitEpsilon,
524 discretionaryHyphenWidth,
525 usesPrefixWidths,
526 )
527 if (fitCount === 0) return false
528
529 lineW = fittedWidth
530 lineEndSegmentIndex = segmentIndex
531 lineEndGraphemeIndex = fitCount
532 clearPendingBreak()
533
534 if (fitCount === gWidths.length) {
535 lineEndSegmentIndex = segmentIndex + 1
536 lineEndGraphemeIndex = 0
537 return true
538 }
539
540 emitCurrentLine(
541 segmentIndex,
542 fitCount,
543 fittedWidth + discretionaryHyphenWidth,
544 )
545 appendBreakableSegmentFrom(segmentIndex, fitCount)
546 return true
547 }
548
549 function emitEmptyChunk(chunk: { startSegmentIndex: number, consumedEndSegmentIndex: number }): void {
550 lineCount++
551 onLine?.({
552 startSegmentIndex: chunk.startSegmentIndex,
553 startGraphemeIndex: 0,
554 endSegmentIndex: chunk.consumedEndSegmentIndex,
555 endGraphemeIndex: 0,
556 width: 0,
557 })
558 clearPendingBreak()
559 }
560
561 for (let chunkIndex = 0; chunkIndex < chunks.length; chunkIndex++) {
562 const chunk = chunks[chunkIndex]!
563 if (chunk.startSegmentIndex === chunk.endSegmentIndex) {
564 emitEmptyChunk(chunk)
565 continue
566 }
567
568 hasContent = false
569 lineW = 0
570 lineStartSegmentIndex = chunk.startSegmentIndex
571 lineStartGraphemeIndex = 0
572 lineEndSegmentIndex = chunk.startSegmentIndex
573 lineEndGraphemeIndex = 0
574 clearPendingBreak()
575
576 let i = chunk.startSegmentIndex
577 while (i < chunk.endSegmentIndex) {
578 const kind = kinds[i]!
579 const w = kind === 'tab' ? getTabAdvance(lineW, tabStopAdvance) : widths[i]!
580
581 if (kind === 'soft-hyphen') {
582 if (hasContent) {
583 lineEndSegmentIndex = i + 1
584 lineEndGraphemeIndex = 0
585 pendingBreakSegmentIndex = i + 1
586 pendingBreakFitWidth = lineW + discretionaryHyphenWidth
587 pendingBreakPaintWidth = lineW + discretionaryHyphenWidth
588 pendingBreakKind = kind
589 }
590 i++
591 continue
592 }
593
594 if (!hasContent) {
595 if (w > maxWidth && breakableWidths[i] !== null) {
596 appendBreakableSegment(i)
597 } else {
598 startLineAtSegment(i, w)
599 }
600 updatePendingBreakForWholeSegment(i, w)
601 i++
602 continue
603 }
604
605 const newW = lineW + w
606 if (newW > maxWidth + lineFitEpsilon) {
607 const currentBreakFitWidth = lineW + (kind === 'tab' ? 0 : lineEndFitAdvances[i]!)
608 const currentBreakPaintWidth = lineW + (kind === 'tab' ? w : lineEndPaintAdvances[i]!)
609
610 if (
611 pendingBreakKind === 'soft-hyphen' &&
612 engineProfile.preferEarlySoftHyphenBreak &&
613 pendingBreakFitWidth <= maxWidth + lineFitEpsilon
614 ) {
615 emitCurrentLine(pendingBreakSegmentIndex, 0, pendingBreakPaintWidth)
616 continue
617 }
618
619 if (pendingBreakKind === 'soft-hyphen' && continueSoftHyphenBreakableSegment(i)) {
620 i++
621 continue
622 }
623
624 if (canBreakAfter(kind) && currentBreakFitWidth <= maxWidth + lineFitEpsilon) {
625 appendWholeSegment(i, w)
626 emitCurrentLine(i + 1, 0, currentBreakPaintWidth)
627 i++
628 continue
629 }
630
631 if (pendingBreakSegmentIndex >= 0 && pendingBreakFitWidth <= maxWidth + lineFitEpsilon) {
632 if (
633 lineEndSegmentIndex > pendingBreakSegmentIndex ||
634 (lineEndSegmentIndex === pendingBreakSegmentIndex && lineEndGraphemeIndex > 0)
635 ) {
636 emitCurrentLine()
637 continue
638 }
639 const nextSegmentIndex = pendingBreakSegmentIndex
640 emitCurrentLine(nextSegmentIndex, 0, pendingBreakPaintWidth)
641 i = nextSegmentIndex
642 continue
643 }
644
645 if (w > maxWidth && breakableWidths[i] !== null) {
646 emitCurrentLine()
647 appendBreakableSegment(i)
648 i++
649 continue
650 }
651
652 emitCurrentLine()
653 continue
654 }
655
656 appendWholeSegment(i, w)
657 updatePendingBreakForWholeSegment(i, w)
658 i++
659 }
660
661 if (hasContent) {
662 const finalPaintWidth =
663 pendingBreakSegmentIndex === chunk.consumedEndSegmentIndex
664 ? pendingBreakPaintWidth
665 : lineW
666 emitCurrentLine(chunk.consumedEndSegmentIndex, 0, finalPaintWidth)
667 }
668 }
669
670 return lineCount
671 }
672
673 export function layoutNextLineRange(
674 prepared: PreparedLineBreakData,
675 start: LineBreakCursor,
676 maxWidth: number,
677 ): InternalLayoutLine | null {
678 const normalizedStart = normalizeLineStart(prepared, start)
679 if (normalizedStart === null) return null
680
681 if (prepared.simpleLineWalkFastPath) {
682 return layoutNextLineRangeSimple(prepared, normalizedStart, maxWidth)
683 }
684
685 const chunkIndex = findChunkIndexForStart(prepared, normalizedStart.segmentIndex)
686 if (chunkIndex < 0) return null
687
688 const chunk = prepared.chunks[chunkIndex]!
689 if (chunk.startSegmentIndex === chunk.endSegmentIndex) {
690 return {
691 startSegmentIndex: chunk.startSegmentIndex,
692 startGraphemeIndex: 0,
693 endSegmentIndex: chunk.consumedEndSegmentIndex,
694 endGraphemeIndex: 0,
695 width: 0,
696 }
697 }
698
699 const {
700 widths,
701 lineEndFitAdvances,
702 lineEndPaintAdvances,
703 kinds,
704 breakableWidths,
705 breakablePrefixWidths,
706 discretionaryHyphenWidth,
707 tabStopAdvance,
708 } = prepared
709 const engineProfile = getEngineProfile()
710 const lineFitEpsilon = engineProfile.lineFitEpsilon
711
712 let lineW = 0
713 let hasContent = false
714 const lineStartSegmentIndex = normalizedStart.segmentIndex
715 const lineStartGraphemeIndex = normalizedStart.graphemeIndex
716 let lineEndSegmentIndex = lineStartSegmentIndex
717 let lineEndGraphemeIndex = lineStartGraphemeIndex
718 let pendingBreakSegmentIndex = -1
719 let pendingBreakFitWidth = 0
720 let pendingBreakPaintWidth = 0
721 let pendingBreakKind: SegmentBreakKind | null = null
722
723 function clearPendingBreak(): void {
724 pendingBreakSegmentIndex = -1
725 pendingBreakFitWidth = 0
726 pendingBreakPaintWidth = 0
727 pendingBreakKind = null
728 }
729
730 function finishLine(
731 endSegmentIndex = lineEndSegmentIndex,
732 endGraphemeIndex = lineEndGraphemeIndex,
733 width = lineW,
734 ): InternalLayoutLine | null {
735 if (!hasContent) return null
736
737 return {
738 startSegmentIndex: lineStartSegmentIndex,
739 startGraphemeIndex: lineStartGraphemeIndex,
740 endSegmentIndex,
741 endGraphemeIndex,
742 width,
743 }
744 }
745
746 function startLineAtSegment(segmentIndex: number, width: number): void {
747 hasContent = true
748 lineEndSegmentIndex = segmentIndex + 1
749 lineEndGraphemeIndex = 0
750 lineW = width
751 }
752
753 function startLineAtGrapheme(segmentIndex: number, graphemeIndex: number, width: number): void {
754 hasContent = true
755 lineEndSegmentIndex = segmentIndex
756 lineEndGraphemeIndex = graphemeIndex + 1
757 lineW = width
758 }
759
760 function appendWholeSegment(segmentIndex: number, width: number): void {
761 if (!hasContent) {
762 startLineAtSegment(segmentIndex, width)
763 return
764 }
765 lineW += width
766 lineEndSegmentIndex = segmentIndex + 1
767 lineEndGraphemeIndex = 0
768 }
769
770 function updatePendingBreakForWholeSegment(segmentIndex: number, segmentWidth: number): void {
771 if (!canBreakAfter(kinds[segmentIndex]!)) return
772 const fitAdvance = kinds[segmentIndex] === 'tab' ? 0 : lineEndFitAdvances[segmentIndex]!
773 const paintAdvance = kinds[segmentIndex] === 'tab' ? segmentWidth : lineEndPaintAdvances[segmentIndex]!
774 pendingBreakSegmentIndex = segmentIndex + 1
775 pendingBreakFitWidth = lineW - segmentWidth + fitAdvance
776 pendingBreakPaintWidth = lineW - segmentWidth + paintAdvance
777 pendingBreakKind = kinds[segmentIndex]!
778 }
779
780 function appendBreakableSegmentFrom(segmentIndex: number, startGraphemeIndex: number): InternalLayoutLine | null {
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba src/line-break.ts | sed -n '780,1084p'"
Chunk ID: 19419f
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 3014
Output:
780 function appendBreakableSegmentFrom(segmentIndex: number, startGraphemeIndex: number): InternalLayoutLine | null {
781 const gWidths = breakableWidths[segmentIndex]!
782 const gPrefixWidths = breakablePrefixWidths[segmentIndex] ?? null
783 for (let g = startGraphemeIndex; g < gWidths.length; g++) {
784 const gw = getBreakableAdvance(
785 gWidths,
786 gPrefixWidths,
787 g,
788 engineProfile.preferPrefixWidthsForBreakableRuns,
789 )
790
791 if (!hasContent) {
792 startLineAtGrapheme(segmentIndex, g, gw)
793 continue
794 }
795
796 if (lineW + gw > maxWidth + lineFitEpsilon) {
797 return finishLine()
798 }
799
800 lineW += gw
801 lineEndSegmentIndex = segmentIndex
802 lineEndGraphemeIndex = g + 1
803 }
804
805 if (hasContent && lineEndSegmentIndex === segmentIndex && lineEndGraphemeIndex === gWidths.length) {
806 lineEndSegmentIndex = segmentIndex + 1
807 lineEndGraphemeIndex = 0
808 }
809 return null
810 }
811
812 function maybeFinishAtSoftHyphen(segmentIndex: number): InternalLayoutLine | null {
813 if (pendingBreakKind !== 'soft-hyphen' || pendingBreakSegmentIndex < 0) return null
814
815 const gWidths = breakableWidths[segmentIndex] ?? null
816 if (gWidths !== null) {
817 const fitWidths = engineProfile.preferPrefixWidthsForBreakableRuns
818 ? breakablePrefixWidths[segmentIndex] ?? gWidths
819 : gWidths
820 const usesPrefixWidths = fitWidths !== gWidths
821 const { fitCount, fittedWidth } = fitSoftHyphenBreak(
822 fitWidths,
823 lineW,
824 maxWidth,
825 lineFitEpsilon,
826 discretionaryHyphenWidth,
827 usesPrefixWidths,
828 )
829
830 if (fitCount === gWidths.length) {
831 lineW = fittedWidth
832 lineEndSegmentIndex = segmentIndex + 1
833 lineEndGraphemeIndex = 0
834 clearPendingBreak()
835 return null
836 }
837
838 if (fitCount > 0) {
839 return finishLine(
840 segmentIndex,
841 fitCount,
842 fittedWidth + discretionaryHyphenWidth,
843 )
844 }
845 }
846
847 if (pendingBreakFitWidth <= maxWidth + lineFitEpsilon) {
848 return finishLine(pendingBreakSegmentIndex, 0, pendingBreakPaintWidth)
849 }
850
851 return null
852 }
853
854 for (let i = normalizedStart.segmentIndex; i < chunk.endSegmentIndex; i++) {
855 const kind = kinds[i]!
856 const startGraphemeIndex = i === normalizedStart.segmentIndex ? normalizedStart.graphemeIndex : 0
857 const w = kind === 'tab' ? getTabAdvance(lineW, tabStopAdvance) : widths[i]!
858
859 if (kind === 'soft-hyphen' && startGraphemeIndex === 0) {
860 if (hasContent) {
861 lineEndSegmentIndex = i + 1
862 lineEndGraphemeIndex = 0
863 pendingBreakSegmentIndex = i + 1
864 pendingBreakFitWidth = lineW + discretionaryHyphenWidth
865 pendingBreakPaintWidth = lineW + discretionaryHyphenWidth
866 pendingBreakKind = kind
867 }
868 continue
869 }
870
871 if (!hasContent) {
872 if (startGraphemeIndex > 0) {
873 const line = appendBreakableSegmentFrom(i, startGraphemeIndex)
874 if (line !== null) return line
875 } else if (w > maxWidth && breakableWidths[i] !== null) {
876 const line = appendBreakableSegmentFrom(i, 0)
877 if (line !== null) return line
878 } else {
879 startLineAtSegment(i, w)
880 }
881 updatePendingBreakForWholeSegment(i, w)
882 continue
883 }
884
885 const newW = lineW + w
886 if (newW > maxWidth + lineFitEpsilon) {
887 const currentBreakFitWidth = lineW + (kind === 'tab' ? 0 : lineEndFitAdvances[i]!)
888 const currentBreakPaintWidth = lineW + (kind === 'tab' ? w : lineEndPaintAdvances[i]!)
889
890 if (
891 pendingBreakKind === 'soft-hyphen' &&
892 engineProfile.preferEarlySoftHyphenBreak &&
893 pendingBreakFitWidth <= maxWidth + lineFitEpsilon
894 ) {
895 return finishLine(pendingBreakSegmentIndex, 0, pendingBreakPaintWidth)
896 }
897
898 const softBreakLine = maybeFinishAtSoftHyphen(i)
899 if (softBreakLine !== null) return softBreakLine
900
901 if (canBreakAfter(kind) && currentBreakFitWidth <= maxWidth + lineFitEpsilon) {
902 appendWholeSegment(i, w)
903 return finishLine(i + 1, 0, currentBreakPaintWidth)
904 }
905
906 if (pendingBreakSegmentIndex >= 0 && pendingBreakFitWidth <= maxWidth + lineFitEpsilon) {
907 if (
908 lineEndSegmentIndex > pendingBreakSegmentIndex ||
909 (lineEndSegmentIndex === pendingBreakSegmentIndex && lineEndGraphemeIndex > 0)
910 ) {
911 return finishLine()
912 }
913 return finishLine(pendingBreakSegmentIndex, 0, pendingBreakPaintWidth)
914 }
915
916 if (w > maxWidth && breakableWidths[i] !== null) {
917 const currentLine = finishLine()
918 if (currentLine !== null) return currentLine
919 const line = appendBreakableSegmentFrom(i, 0)
920 if (line !== null) return line
921 }
922
923 return finishLine()
924 }
925
926 appendWholeSegment(i, w)
927 updatePendingBreakForWholeSegment(i, w)
928 }
929
930 if (pendingBreakSegmentIndex === chunk.consumedEndSegmentIndex && lineEndGraphemeIndex === 0) {
931 return finishLine(chunk.consumedEndSegmentIndex, 0, pendingBreakPaintWidth)
932 }
933
934 return finishLine(chunk.consumedEndSegmentIndex, 0, lineW)
935 }
936
937 function layoutNextLineRangeSimple(
938 prepared: PreparedLineBreakData,
939 normalizedStart: LineBreakCursor,
940 maxWidth: number,
941 ): InternalLayoutLine | null {
942 const { widths, kinds, breakableWidths, breakablePrefixWidths } = prepared
943 const engineProfile = getEngineProfile()
944 const lineFitEpsilon = engineProfile.lineFitEpsilon
945
946 let lineW = 0
947 let hasContent = false
948 const lineStartSegmentIndex = normalizedStart.segmentIndex
949 const lineStartGraphemeIndex = normalizedStart.graphemeIndex
950 let lineEndSegmentIndex = lineStartSegmentIndex
951 let lineEndGraphemeIndex = lineStartGraphemeIndex
952 let pendingBreakSegmentIndex = -1
953 let pendingBreakPaintWidth = 0
954
955 function finishLine(
956 endSegmentIndex = lineEndSegmentIndex,
957 endGraphemeIndex = lineEndGraphemeIndex,
958 width = lineW,
959 ): InternalLayoutLine | null {
960 if (!hasContent) return null
961
962 return {
963 startSegmentIndex: lineStartSegmentIndex,
964 startGraphemeIndex: lineStartGraphemeIndex,
965 endSegmentIndex,
966 endGraphemeIndex,
967 width,
968 }
969 }
970
971 function startLineAtSegment(segmentIndex: number, width: number): void {
972 hasContent = true
973 lineEndSegmentIndex = segmentIndex + 1
974 lineEndGraphemeIndex = 0
975 lineW = width
976 }
977
978 function startLineAtGrapheme(segmentIndex: number, graphemeIndex: number, width: number): void {
979 hasContent = true
980 lineEndSegmentIndex = segmentIndex
981 lineEndGraphemeIndex = graphemeIndex + 1
982 lineW = width
983 }
984
985 function appendWholeSegment(segmentIndex: number, width: number): void {
986 if (!hasContent) {
987 startLineAtSegment(segmentIndex, width)
988 return
989 }
990 lineW += width
991 lineEndSegmentIndex = segmentIndex + 1
992 lineEndGraphemeIndex = 0
993 }
994
995 function updatePendingBreak(segmentIndex: number, segmentWidth: number): void {
996 if (!canBreakAfter(kinds[segmentIndex]!)) return
997 pendingBreakSegmentIndex = segmentIndex + 1
998 pendingBreakPaintWidth = lineW - segmentWidth
999 }
1000
1001 function appendBreakableSegmentFrom(segmentIndex: number, startGraphemeIndex: number): InternalLayoutLine | null {
1002 const gWidths = breakableWidths[segmentIndex]!
1003 const gPrefixWidths = breakablePrefixWidths[segmentIndex] ?? null
1004 for (let g = startGraphemeIndex; g < gWidths.length; g++) {
1005 const gw = getBreakableAdvance(
1006 gWidths,
1007 gPrefixWidths,
1008 g,
1009 engineProfile.preferPrefixWidthsForBreakableRuns,
1010 )
1011
1012 if (!hasContent) {
1013 startLineAtGrapheme(segmentIndex, g, gw)
1014 continue
1015 }
1016
1017 if (lineW + gw > maxWidth + lineFitEpsilon) {
1018 return finishLine()
1019 }
1020
1021 lineW += gw
1022 lineEndSegmentIndex = segmentIndex
1023 lineEndGraphemeIndex = g + 1
1024 }
1025
1026 if (hasContent && lineEndSegmentIndex === segmentIndex && lineEndGraphemeIndex === gWidths.length) {
1027 lineEndSegmentIndex = segmentIndex + 1
1028 lineEndGraphemeIndex = 0
1029 }
1030 return null
1031 }
1032
1033 for (let i = normalizedStart.segmentIndex; i < widths.length; i++) {
1034 const w = widths[i]!
1035 const kind = kinds[i]!
1036 const startGraphemeIndex = i === normalizedStart.segmentIndex ? normalizedStart.graphemeIndex : 0
1037
1038 if (!hasContent) {
1039 if (startGraphemeIndex > 0) {
1040 const line = appendBreakableSegmentFrom(i, startGraphemeIndex)
1041 if (line !== null) return line
1042 } else if (w > maxWidth && breakableWidths[i] !== null) {
1043 const line = appendBreakableSegmentFrom(i, 0)
1044 if (line !== null) return line
1045 } else {
1046 startLineAtSegment(i, w)
1047 }
1048 updatePendingBreak(i, w)
1049 continue
1050 }
1051
1052 const newW = lineW + w
1053 if (newW > maxWidth + lineFitEpsilon) {
1054 if (canBreakAfter(kind)) {
1055 appendWholeSegment(i, w)
1056 return finishLine(i + 1, 0, lineW - w)
1057 }
1058
1059 if (pendingBreakSegmentIndex >= 0) {
1060 if (
1061 lineEndSegmentIndex > pendingBreakSegmentIndex ||
1062 (lineEndSegmentIndex === pendingBreakSegmentIndex && lineEndGraphemeIndex > 0)
1063 ) {
1064 return finishLine()
1065 }
1066 return finishLine(pendingBreakSegmentIndex, 0, pendingBreakPaintWidth)
1067 }
1068
1069 if (w > maxWidth && breakableWidths[i] !== null) {
1070 const currentLine = finishLine()
1071 if (currentLine !== null) return currentLine
1072 const line = appendBreakableSegmentFrom(i, 0)
1073 if (line !== null) return line
1074 }
1075
1076 return finishLine()
1077 }
1078
1079 appendWholeSegment(i, w)
1080 updatePendingBreak(i, w)
1081 }
1082
1083 return finishLine()
1084 }
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba pages/demos/masonry/index.ts | sed -n '1,220p'",
"max_output_tokens": 8000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && rg -n \"layoutNextLine|walkLineRanges|binary search|fitHeadlineFontSize|layoutColumn|getWrapHull|projectTextProjection\" pages/demos/dynamic-layout.ts pages/demos/editorial-engine.ts pages/demos/rich-note.ts pages/demos/justification-comparison.model.ts pages/demos/bubbles-shared.ts",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba pages/demos/bubbles-shared.ts | sed -n '1,160p'",
"max_output_tokens": 8000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba pages/demos/justification-comparison.model.ts | sed -n '1,220p'",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba pages/demos/masonry/index.ts | sed -n '1,220p'"
Chunk ID: 39f957
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 1481
Output:
1 import { prepare, layout, type PreparedText } from '../../../src/layout.ts'
2 import rawThoughts from './shower-thoughts.json'
3
4 // --- config ---
5 const font = '15px "Helvetica Neue", Helvetica, Arial, sans-serif'
6 const lineHeight = 22
7 const cardPadding = 16
8 const gap = 12
9 const maxColWidth = 400
10 const singleColumnMaxViewportWidth = 520
11
12 type Card = {
13 text: string
14 prepared: PreparedText
15 }
16
17 type PositionedCard = {
18 cardIndex: number
19 x: number
20 y: number
21 h: number
22 }
23
24 type LayoutState = {
25 colWidth: number
26 contentHeight: number
27 positionedCards: PositionedCard[]
28 }
29
30 type State = {
31 cards: Card[]
32 }
33
34 // --- prepare all texts upfront ---
35 const st: State = {
36 cards: rawThoughts.map(text => ({
37 text,
38 prepared: prepare(text, font),
39 })),
40 }
41
42 type DomCache = {
43 container: HTMLDivElement // cache lifetime: same as app
44 cards: Array // cache lifetime: on visibility changes
45 }
46
47 const domCache: DomCache = {
48 container: document.createElement('div'),
49 cards: [],
50 }
51
52 domCache.container.style.position = 'relative'
53 document.body.appendChild(domCache.container)
54
55 function computeLayout(windowWidth: number): LayoutState {
56 let colCount: number
57 let colWidth: number
58 if (windowWidth <= singleColumnMaxViewportWidth) {
59 colCount = 1
60 colWidth = Math.min(maxColWidth, windowWidth - gap * 2)
61 } else {
62 const minColWidth = 100 + windowWidth * 0.1
63 colCount = Math.max(2, Math.floor((windowWidth + gap) / (minColWidth + gap)))
64 colWidth = Math.min(maxColWidth, (windowWidth - (colCount + 1) * gap) / colCount)
65 }
66 const textWidth = colWidth - cardPadding * 2
67 const contentWidth = colCount * colWidth + (colCount - 1) * gap
68 const offsetLeft = (windowWidth - contentWidth) / 2
69
70 const colHeights = new Float64Array(colCount)
71 for (let c = 0; c < colCount; c++) colHeights[c] = gap
72
73 const positionedCards: PositionedCard[] = []
74 for (let i = 0; i < st.cards.length; i++) {
75 let shortest = 0
76 for (let c = 1; c < colCount; c++) {
77 if (colHeights[c]! < colHeights[shortest]!) shortest = c
78 }
79
80 const { height } = layout(st.cards[i]!.prepared, textWidth, lineHeight)
81 const totalH = height + cardPadding * 2
82
83 positionedCards.push({
84 cardIndex: i,
85 x: offsetLeft + shortest * (colWidth + gap),
86 y: colHeights[shortest]!,
87 h: totalH,
88 })
89
90 colHeights[shortest]! += totalH + gap
91 }
92
93 let contentHeight = 0
94 for (let c = 0; c < colCount; c++) {
95 if (colHeights[c]! > contentHeight) contentHeight = colHeights[c]!
96 }
97
98 return { colWidth, contentHeight, positionedCards }
99 }
100
101 function getOrCreateCardNode(cardIndex: number): HTMLDivElement {
102 const existingNode = domCache.cards[cardIndex]
103 if (existingNode) return existingNode
104
105 const node = document.createElement('div')
106 node.className = 'card'
107 node.textContent = st.cards[cardIndex]!.text
108 domCache.container.appendChild(node)
109 domCache.cards[cardIndex] = node
110 return node
111 }
112
113 // --- events ---
114 window.addEventListener('resize', () => scheduleRender())
115 window.addEventListener('scroll', () => scheduleRender(), true)
116
117 let scheduledRaf: number | null = null
118 function scheduleRender() {
119 if (scheduledRaf != null) return
120 scheduledRaf = requestAnimationFrame(function renderAndMaybeScheduleAnotherRender() {
121 scheduledRaf = null
122 render()
123 })
124 }
125
126 function render() {
127 // --- DOM reads ---
128 const windowWidth = document.documentElement.clientWidth
129 const windowHeight = document.documentElement.clientHeight
130 const scrollTop = window.scrollY
131
132 const layoutState = computeLayout(windowWidth)
133 domCache.container.style.height = `${layoutState.contentHeight}px`
134
135 // --- visibility + DOM writes (single pass) ---
136 const viewTop = scrollTop - 200
137 const viewBottom = scrollTop + windowHeight + 200
138 const visibleFlags = new Uint8Array(st.cards.length)
139
140 for (let i = 0; i < layoutState.positionedCards.length; i++) {
141 const positionedCard = layoutState.positionedCards[i]!
142 if (positionedCard.y > viewBottom || positionedCard.y + positionedCard.h < viewTop) continue
143
144 visibleFlags[positionedCard.cardIndex] = 1
145 const node = getOrCreateCardNode(positionedCard.cardIndex)
146 node.style.left = `${positionedCard.x}px`
147 node.style.top = `${positionedCard.y}px`
148 node.style.width = `${layoutState.colWidth}px`
149 node.style.height = `${positionedCard.h}px`
150 }
151
152 for (let cardIndex = 0; cardIndex < domCache.cards.length; cardIndex++) {
153 const node = domCache.cards[cardIndex]
154 if (node && visibleFlags[cardIndex] === 0) {
155 node.remove()
156 domCache.cards[cardIndex] = undefined
157 }
158 }
159 }
160
161 scheduleRender()
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc 'cd /Users/maxgeorgopoulos/Documents/experiments/pretext && rg -n "layoutNextLine|walkLineRanges|binary search|fitHeadlineFontSize|layoutColumn|getWrapHull|projectTextProjection" pages/demos/dynamic-layout.ts pages/demos/editorial-engine.ts pages/demos/rich-note.ts pages/demos/justification-comparison.model.ts pages/demos/bubbles-shared.ts'
Chunk ID: eb5039
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 907
Output:
pages/demos/justification-comparison.model.ts
3: layoutNextLine,
225: const line = layoutNextLine(prepared, cursor, maxWidth)
pages/demos/rich-note.ts
2: layoutNextLine,
4: walkLineRanges,
124: { kind: 'text', text: 'layoutNextLine()', style: 'code' },
189: walkLineRanges(prepared, UNBOUNDED_WIDTH, line => {
237: const wholeLine = layoutNextLine(prepared, LINE_START_CURSOR, UNBOUNDED_WIDTH)
322: const line = layoutNextLine(
pages/demos/editorial-engine.ts
2: layoutNextLine,
5: walkLineRanges,
214:Shrinkwrap is another capability that CSS cannot express. Given a block of multiline text, what is the narrowest width that preserves the current line count? CSS offers fit-content, which works for single lines but always leaves dead space for multiline text. Pretext solves this with a binary search over widths: narrow until the line count increases, then back off. The result is the tightest possible bounding box — perfect for chat message bubbles, image captions, and tooltip text.
220:Pretext makes it trivial. Call layoutNextLine in a loop for the first column, using the column width. When the column is full, take the returned cursor and start a new loop for the second column. The cursor carries the exact position in the prepared text — which segment, which grapheme within that segment. The second column continues seamlessly from the first.
222:Adaptive headline sizing is a detail that separates professional typography from amateur layout. The headline should be as large as possible without breaking any word across lines. This requires a binary search: try a font size, measure the text, check if any line breaks occur within a word, and adjust. With DOM measurement, each iteration costs a reflow. With pretext, each iteration is a microsecond of arithmetic.
289:walkLineRanges(preparedDropCap, 9999, line => {
376: walkLineRanges(prepared, maxWidth, line => {
402:function layoutColumn(
463: const line = layoutNextLine(prepared, cursor, slotWidth)
545:function projectTextProjection(projection: TextProjection): void {
875: const result = layoutColumn(
924: projectTextProjection(textProjection)
pages/demos/bubbles-shared.ts
1:import { layout, prepareWithSegments, walkLineRanges, type PreparedTextWithSegments } from '../../src/layout.ts'
51: const lineCount = walkLineRanges(prepared, maxWidth, line => {
pages/demos/dynamic-layout.ts
24:import { layoutNextLine, prepareWithSegments, walkLineRanges, type LayoutCursor, type PreparedTextWithSegments } from '../../src/layout.ts'
32: getWrapHull,
213: getWrapHull(OPENAI_LOGO_SRC, { smoothRadius: 6, mode: 'mean' }),
214: getWrapHull(CLAUDE_LOGO_SRC, { smoothRadius: 6, mode: 'mean' }),
215: getWrapHull(OPENAI_LOGO_SRC, { smoothRadius: 3, mode: 'mean' }),
216: getWrapHull(CLAUDE_LOGO_SRC, { smoothRadius: 5, mode: 'mean' }),
238: walkLineRanges(prepared, 100_000, line => {
246: walkLineRanges(prepared, maxWidth, line => {
275:function layoutColumn(
326: const line = layoutNextLine(prepared, cursor, width)
439:function projectTextProjection(projection: TextProjection): void {
473:function fitHeadlineFontSize(headlineWidth: number, pageWidth: number): number {
572: const headlineFontSize = Math.min(48, fitHeadlineFontSize(headlineWidth, pageWidth))
621: const headlineFontSize = fitHeadlineFontSize(headlineWidth, pageWidth)
684: const headlineResult = layoutColumn(
763: const bodyResult = layoutColumn(
783: const leftResult = layoutColumn(
792: const rightResult = layoutColumn(
843: projectTextProjection(textProjection)
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba pages/demos/bubbles-shared.ts | sed -n '1,160p'"
Chunk ID: 3e12fc
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 1061
Output:
1 import { layout, prepareWithSegments, walkLineRanges, type PreparedTextWithSegments } from '../../src/layout.ts'
2
3 export type WrapMetrics = {
4 lineCount: number
5 height: number
6 maxLineWidth: number
7 }
8
9 export type PreparedBubble = {
10 prepared: PreparedTextWithSegments
11 }
12
13 export type BubbleRenderWidths = {
14 cssWidth: number
15 tightWidth: number
16 }
17
18 export type BubbleRenderState = {
19 chatWidth: number
20 bubbleMaxWidth: number
21 totalWastedPixels: number
22 widths: BubbleRenderWidths[]
23 }
24
25 export const FONT = '15px "Helvetica Neue", Helvetica, Arial, sans-serif'
26 export const LINE_HEIGHT = 20
27 export const PADDING_H = 12
28 export const PADDING_V = 8
29 export const BUBBLE_MAX_RATIO = 0.8
30 export const PAGE_MAX_WIDTH = 1080
31 export const DESKTOP_PAGE_MARGIN = 32
32 export const MOBILE_PAGE_MARGIN = 20
33 export const GRID_GAP = 16
34 export const PANEL_PADDING_X = 36
35
36 export function prepareBubbleTexts(texts: string[]): PreparedBubble[] {
37 return texts.map(text => ({
38 prepared: prepareWithSegments(text, FONT),
39 }))
40 }
41
42 export function getMaxChatWidth(minWidth: number, viewportWidth: number): number {
43 const pageWidth = Math.min(PAGE_MAX_WIDTH, viewportWidth - (viewportWidth <= 760 ? MOBILE_PAGE_MARGIN : DESKTOP_PAGE_MARGIN))
44 const columnWidth = viewportWidth <= 760 ? pageWidth : (pageWidth - GRID_GAP) / 2
45 const panelContentWidth = Math.max(1, Math.floor(columnWidth - PANEL_PADDING_X))
46 return Math.max(minWidth, panelContentWidth)
47 }
48
49 export function collectWrapMetrics(prepared: PreparedTextWithSegments, maxWidth: number): WrapMetrics {
50 let maxLineWidth = 0
51 const lineCount = walkLineRanges(prepared, maxWidth, line => {
52 if (line.width > maxLineWidth) maxLineWidth = line.width
53 })
54 return {
55 lineCount,
56 height: lineCount * LINE_HEIGHT,
57 maxLineWidth,
58 }
59 }
60
61 export function findTightWrapMetrics(prepared: PreparedTextWithSegments, maxWidth: number): WrapMetrics {
62 const initial = collectWrapMetrics(prepared, maxWidth)
63 let lo = 1
64 let hi = Math.max(1, Math.ceil(maxWidth))
65
66 while (lo < hi) {
67 const mid = Math.floor((lo + hi) / 2)
68 const midLineCount = layout(prepared, mid, LINE_HEIGHT).lineCount
69 if (midLineCount <= initial.lineCount) {
70 hi = mid
71 } else {
72 lo = mid + 1
73 }
74 }
75
76 return collectWrapMetrics(prepared, lo)
77 }
78
79 export function computeBubbleRender(preparedBubbles: PreparedBubble[], chatWidth: number): BubbleRenderState {
80 const bubbleMaxWidth = Math.floor(chatWidth * BUBBLE_MAX_RATIO)
81 const contentMaxWidth = bubbleMaxWidth - PADDING_H * 2
82 let totalWastedPixels = 0
83 const widths: BubbleRenderWidths[] = []
84
85 for (let index = 0; index < preparedBubbles.length; index++) {
86 const bubble = preparedBubbles[index]!
87 const cssMetrics = collectWrapMetrics(bubble.prepared, contentMaxWidth)
88 const tightMetrics = findTightWrapMetrics(bubble.prepared, contentMaxWidth)
89
90 const cssWidth = Math.ceil(cssMetrics.maxLineWidth) + PADDING_H * 2
91 const tightWidth = Math.ceil(tightMetrics.maxLineWidth) + PADDING_H * 2
92 const cssHeight = cssMetrics.height + PADDING_V * 2
93 totalWastedPixels += Math.max(0, cssWidth - tightWidth) * cssHeight
94 widths.push({ cssWidth, tightWidth })
95 }
96
97 return {
98 chatWidth,
99 bubbleMaxWidth,
100 totalWastedPixels,
101 widths,
102 }
103 }
104
105 export function formatPixelCount(value: number): string {
106 return `${Math.round(value).toLocaleString()}`
107 }
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && nl -ba pages/demos/justification-comparison.model.ts | sed -n '1,220p'"
Chunk ID: 28162e
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 1987
Output:
1 import {
2 prepareWithSegments,
3 layoutNextLine,
4 type LayoutCursor,
5 type PreparedTextWithSegments,
6 } from '../../src/layout.ts'
7 import {
8 FONT,
9 HYPHEN_EXCEPTIONS,
10 LINE_HEIGHT,
11 PAD,
12 PARA_GAP,
13 PARAGRAPHS,
14 PREFIXES,
15 SUFFIXES,
16 } from './justification-comparison.data.ts'
17
18 const HUGE_BADNESS = 1e8
19 const SOFT_HYPHEN = '\u00AD'
20 const SHORT_LINE_RATIO = 0.6
21 const RIVER_THRESHOLD = 1.5
22 const INFEASIBLE_SPACE_RATIO = 0.4
23 const OVERFLOW_SPACE_RATIO = 0.2
24 const MIN_READABLE_SPACE_RATIO = 0.75
25 const TIGHT_SPACE_RATIO = 0.65
26
27 export type DemoControls = {
28 colWidth: number
29 showIndicators: boolean
30 }
31
32 export type DemoResources = {
33 basePreparedParagraphs: PreparedTextWithSegments[]
34 hyphenatedPreparedParagraphs: PreparedTextWithSegments[]
35 normalSpaceWidth: number
36 hyphenWidth: number
37 }
38
39 type TrailingMarker = 'none' | 'soft-hyphen'
40 type LineEnding = 'paragraph-end' | 'wrap'
41 type BreakCandidateKind = 'start' | 'space' | 'soft-hyphen' | 'end'
42
43 export type LineSegment =
44 | { kind: 'text'; text: string; width: number }
45 | { kind: 'space'; width: number }
46
47 export type MeasuredLine = {
48 segments: LineSegment[]
49 wordWidth: number
50 spaceCount: number
51 naturalWidth: number
52 maxWidth: number
53 ending: LineEnding
54 trailingMarker: TrailingMarker
55 }
56
57 export type LineSpacing =
58 | { kind: 'ragged' }
59 | { kind: 'overflow' }
60 | { kind: 'justified'; width: number; isRiver: boolean }
61
62 export type PositionedLine = MeasuredLine & {
63 y: number
64 spacing: LineSpacing
65 }
66
67 export type QualityMetrics = {
68 avgDeviation: number
69 maxDeviation: number
70 riverCount: number
71 lineCount: number
72 }
73
74 export type CanvasColumnFrame = {
75 colWidth: number
76 totalHeight: number
77 paragraphs: PositionedLine[][]
78 metrics: QualityMetrics
79 }
80
81 export type DemoFrame = {
82 controls: DemoControls
83 css: {
84 metrics: QualityMetrics
85 }
86 hyphen: CanvasColumnFrame
87 optimal: CanvasColumnFrame
88 }
89
90 export type RiverIndicator = {
91 red: number
92 green: number
93 blue: number
94 alpha: number
95 }
96
97 type BreakCandidate = {
98 segIndex: number
99 kind: BreakCandidateKind
100 }
101
102 type LineStats = {
103 wordWidth: number
104 spaceCount: number
105 naturalWidth: number
106 trailingMarker: TrailingMarker
107 }
108
109 export function createDemoResources(): DemoResources {
110 const measureCanvas = document.createElement('canvas')
111 const measureCtx = measureCanvas.getContext('2d')
112 if (measureCtx === null) throw new Error('2D canvas context is required for the demo')
113 measureCtx.font = FONT
114
115 return {
116 basePreparedParagraphs: PARAGRAPHS.map(paragraph => prepareWithSegments(paragraph, FONT)),
117 hyphenatedPreparedParagraphs: PARAGRAPHS.map(paragraph => prepareWithSegments(hyphenateParagraphText(paragraph), FONT)),
118 normalSpaceWidth: measureCtx.measureText(' ').width,
119 hyphenWidth: measureCtx.measureText('-').width,
120 }
121 }
122
123 export function buildDemoFrame(resources: DemoResources, controls: DemoControls): DemoFrame {
124 const innerWidth = controls.colWidth - PAD * 2
125
126 const cssParagraphs = layoutParagraphsGreedy(resources.basePreparedParagraphs, innerWidth, resources.hyphenWidth)
127 const hyphenParagraphs = layoutParagraphsGreedy(resources.hyphenatedPreparedParagraphs, innerWidth, resources.hyphenWidth)
128 const optimalParagraphs = layoutParagraphsOptimal(resources.hyphenatedPreparedParagraphs, innerWidth, resources)
129
130 return {
131 controls,
132 css: {
133 metrics: computeMetrics(cssParagraphs, resources.normalSpaceWidth),
134 },
135 hyphen: buildCanvasColumnFrame(controls.colWidth, hyphenParagraphs, resources.normalSpaceWidth),
136 optimal: buildCanvasColumnFrame(controls.colWidth, optimalParagraphs, resources.normalSpaceWidth),
137 }
138 }
139
140 export function getRiverIndicator(spaceWidth: number, normalSpaceWidth: number): RiverIndicator | null {
141 if (spaceWidth <= normalSpaceWidth * RIVER_THRESHOLD) return null
142
143 const intensity = Math.min(1, (spaceWidth / normalSpaceWidth - RIVER_THRESHOLD) / RIVER_THRESHOLD)
144 return {
145 red: Math.round(220 + intensity * 35),
146 green: Math.round(180 - intensity * 80),
147 blue: Math.round(180 - intensity * 80),
148 alpha: 0.25 + intensity * 0.35,
149 }
150 }
151
152 function hyphenateParagraphText(paragraph: string): string {
153 const words = paragraph.split(/(\s+)/)
154 let hyphenated = ''
155 for (let index = 0; index < words.length; index++) {
156 const token = words[index]!
157 if (/^\s+$/.test(token)) {
158 hyphenated += token
159 continue
160 }
161 const parts = hyphenateWord(token)
162 hyphenated += parts.length <= 1 ? token : parts.join(SOFT_HYPHEN)
163 }
164 return hyphenated
165 }
166
167 function hyphenateWord(word: string): string[] {
168 const lower = word.toLowerCase().replace(/[.,;:!?"'—–-]/g, '')
169 if (lower.length < 5) return [word]
170
171 const exactMatch = HYPHEN_EXCEPTIONS[lower]
172 if (exactMatch !== undefined) {
173 const parts: string[] = []
174 let position = 0
175 for (let index = 0; index < exactMatch.length; index++) {
176 const part = exactMatch[index]!
177 parts.push(word.slice(position, position + part.length))
178 position += part.length
179 }
180 if (position < word.length) {
181 parts[parts.length - 1] += word.slice(position)
182 }
183 return parts
184 }
185
186 for (let index = 0; index < PREFIXES.length; index++) {
187 const prefix = PREFIXES[index]!
188 if (lower.startsWith(prefix) && lower.length - prefix.length >= 3) {
189 return [word.slice(0, prefix.length), word.slice(prefix.length)]
190 }
191 }
192
193 for (let index = 0; index < SUFFIXES.length; index++) {
194 const suffix = SUFFIXES[index]!
195 if (lower.endsWith(suffix) && lower.length - suffix.length >= 3) {
196 const cut = word.length - suffix.length
197 return [word.slice(0, cut), word.slice(cut)]
198 }
199 }
200
201 return [word]
202 }
203
204 function layoutParagraphsGreedy(
205 preparedParagraphs: PreparedTextWithSegments[],
206 maxWidth: number,
207 hyphenWidth: number,
208 ): MeasuredLine[][] {
209 const paragraphs: MeasuredLine[][] = []
210 for (let index = 0; index < preparedParagraphs.length; index++) {
211 paragraphs.push(layoutParagraphGreedy(preparedParagraphs[index]!, maxWidth, hyphenWidth))
212 }
213 return paragraphs
214 }
215
216 function layoutParagraphGreedy(
217 prepared: PreparedTextWithSegments,
218 maxWidth: number,
219 hyphenWidth: number,
220 ): MeasuredLine[] {
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git log --reverse --date=short --pretty=format:'%ad %h %s' | head -n 80",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git log --date=short --pretty=format:'%ad %h %s' -- src/layout.ts src/analysis.ts src/line-break.ts src/measurement.ts src/bidi.ts | head -n 80",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show --stat --oneline --no-patch 3e991df d988bb0 f06fb75 cfdc371 a28df8c d18bb75 38c7090 8e305a7 39b38e5 0f889e6",
"max_output_tokens": 12000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
### Tool: exec_command
**Args:**
```json
{
"cmd": "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && sed -n '1,240p' thoughts.md",
"max_output_tokens": 4000,
"tty": true,
"yield_time_ms": 1000
}
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git log --reverse --date=short --pretty=format:'%ad %h %s' | head -n 80"
Chunk ID: 846fe3
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 1434
Output:
2026-03-03 f962f72 Initial project setup
2026-03-03 f0f03ba Add oxlint config with type-aware linting
2026-03-03 1d3941e Add accuracy sweep page
2026-03-03 dfd40ed Add headless test suite with HarfBuzz measurement
2026-03-03 d399fc4 Add word-sum vs full-line accuracy test
2026-03-03 0167c1e Fix HarfBuzz direction: explicit LTR for consistent measurement
2026-03-03 820e8e1 Add comments documenting motivations throughout
2026-03-03 c78b35a Write README documenting problem, solution, perf, accuracy, i18n, limitations, how it works, what we tried and rejected, and credits
2026-03-03 ead6bd7 Update CLAUDE.md with test commands, file inventory, rejected approaches
2026-03-03 a797983 Remove serve.ts, use bun's direct HTML serving
2026-03-03 61c1e25 Add RESEARCH.md, consolidate docs, rename serve to start
2026-03-03 73783d0 Add line-break diagnostic, document Safari CSS behavior differences
2026-03-03 f54a344 Revert trailing space experiment — restore Chrome 99.4%
2026-03-03 08a1404 Document Safari CSS line-breaking differences in RESEARCH.md
2026-03-03 e0837f6 Update CLAUDE.md and README for fresh session handoff
2026-03-03 91304c0 Emoji correction, merging fix, overflow handling — Chrome 99.4% → 99.7%
2026-03-03 6ce9982 Kinsoku shori — CJK line-breaking rules, Chrome 99.7% → 99.9%
2026-03-03 315658b Document cache design decision, slim down CLAUDE.md
2026-03-03 e8de24c Fix prepare() perf regression: skip emoji grapheme scan for non-emoji text
2026-03-03 ae466fa Hoist word segmenter to module level, add TODO section
2026-03-03 aff5ba7 Benchmark CJK scaling, cleanup for...of, --no-hmr, NaN guard
2026-03-03 fee6750 Opening bracket forward-merge, CSS config docs, Chrome 3838/3840
2026-03-03 22a2f26 Document word-sum divergence, revert failed fix attempts
2026-03-03 e2f1321 Document char-level experiment, prior art, fix text-layout repo URL
2026-03-03 c48295a Document hybrid verify experiment (99.9% → 99.8%, reverted)
2026-03-04 573b6db Fix emoji correction for Safari — compare canvas vs DOM, not fontSize
2026-03-04 3fd4f01 Document lineHeight default mismatch across browsers
2026-03-04 71c0e58 Document Firefox system-ui font mismatch and Thai segmenter divergence
2026-03-04 1135318 Add browser bug links to RESEARCH.md, update emoji correction docs
2026-03-04 bad8fbc CJK-split all CJK segments, not just word-like — Firefox 99.7% → 99.9%
2026-03-04 48116bd Add Firefox system-ui bug link to RESEARCH.md
2026-03-04 038a812 Add Chrome system-ui bug link to RESEARCH.md
2026-03-04 5f76956 Add Verdana and Courier New to accuracy sweep — 7677/7680 (99.96%)
2026-03-04 b22efa0 Show 2 decimal places for accuracy percentage
2026-03-04 76c2766 Update all docs for 4-font accuracy, clean up stale comments
2026-03-04 7d0a54d Remove checked in chromium issue
2026-03-04 5ecce72 Simplify layout code: flatten data, remove dead computation, cut allocations
2026-03-04 965a546 Update RESEARCH.md with Firefox developer's DPR explanation
2026-03-04 06cb7d0 Add bubble shrinkwrap demo page
2026-03-06 f99df17 Remove interleaving demo stub
2026-03-06 dbebb7d Clean up stale docs and unify test data
2026-03-06 fea1fa7 Split fast and rich layout APIs
2026-03-06 0aca7b6 Link system-ui warnings to RESEARCH.md exploration
2026-03-06 7a4f827 Make lineHeight an explicit layout-time input
2026-03-07 9d37c3a Trim CLAUDE.md to internal notes
2026-03-07 89ed442 Document public layout data fields
2026-03-07 71d5ff4 Improve benchmark methodology for tiny layout timings
2026-03-07 3eabf39 TODOs and more use-cases
2026-03-07 374aece Rename project from text-metrics to pretext
2026-03-07 bf0741a Add unported ancestor ideas to notes
2026-03-07 b1c4041 Move harfbuzzjs from dependencies to devDependencies
2026-03-07 81f7bf1 Clarify break-word docs
2026-03-07 31af255 Clarify CSS config claim and server-side status, add TODOs
2026-03-07 a724b7f Update benchmark snapshot
2026-03-07 d07dd7a gatsby test: first pass
2026-03-07 5cd5762 Add Gatsby diagnostics without regressing hot-path layout
2026-03-07 9af7f63 Close the remaining browser accuracy gaps cheaply
2026-03-07 8f4ac00 Harden browser-accuracy diagnostics without slowing layout
2026-03-08 3f9cb1e Separate prepare analysis from measurement
2026-03-08 84cccc8 Shrink permanent tests to exported invariants
2026-03-08 7137f0a Add a fast Gatsby width sweep
2026-03-08 dfd81ae Harden Gatsby sweep browser automation
2026-03-08 06e6437 Keep apostrophe-led elisions with the following word
2026-03-08 c852293 Simplify merged segmentation and CJK measurement
2026-03-08 3202f3a Add multilingual corpus stress canaries
2026-03-08 16c04fe Improve Arabic and Hindi corpus wrapping
2026-03-08 516e5e6 Make bun start clear stale port 3000 listeners
2026-03-08 bba3624 Benchmark long-form corpora alongside the shared corpus
2026-03-08 cb0a76a Harden corpus mismatch diagnostics
2026-03-08 7fb726d Fingerprint browser test environments and fix Korean quote wraps in Chromium
2026-03-08 cdec07c Clean Arabic corpus artifacts and harden RTL diagnostics
2026-03-08 bc031c3 Document the rejected Arabic shaping experiments
2026-03-08 e7b9cbe Expose logical break offsets in corpus diagnostics
2026-03-09 52fcf70 Add a single-snippet browser line-break probe
2026-03-09 cd8b642 Rename CLAUDE.md to AGENTS.md
2026-03-09 d91a0af Merge Arabic no-space punctuation clusters
2026-03-09 9612485 Refine Arabic preprocessing around punctuation and marks
2026-03-09 1495b5c Fix multilingual corpus diagnostics and clean Arabic source artifacts
2026-03-09 09e6c03 Clean remaining Arabic corpus punctuation artifacts
2026-03-09 8aaf7b8 Keep Arabic punctuation-plus-mark clusters with their word
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git log --date=short --pretty=format:'%ad %h %s' -- src/layout.ts src/analysis.ts src/line-break.ts src/measurement.ts src/bidi.ts | head -n 80"
Chunk ID: 37b8e7
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 1345
Output:
2026-03-31 0f889e6 Route Gatsby through corpus tooling and fix stale pending breaks
2026-03-31 39b38e5 Add rich line round-trip invariants
2026-03-29 75a6e48 Publish built ESM package artifacts
2026-03-28 8e305a7 Only compute prefix widths when the browser needs them
2026-03-28 38c7090 Split simple rich line walking from pre-wrap path
2026-03-28 d18bb75 Restore simple layout fast path
2026-03-28 2fa99fa Simplify pre-wrap tabs and broaden coverage
2026-03-27 98a1ad5 Add tab stops to pre-wrap mode
2026-03-27 a28df8c Rewrite whitespace mode around pre-wrap chunks
2026-03-27 cfdc371 Add preserve-spaces whitespace mode
2026-03-26 3195cb3 Tune Safari line breaking and add input-box demo
2026-03-26 6b7b0e4 Let overlong breakable segments fill the current line
2026-03-26 d2ea9b2 Fix Safari punctuation-chain wrapping
2026-03-26 bc8e0db Refine rich layout internals and docs
2026-03-26 2823649 Refresh benchmark snapshots and simplify rich line API
2026-03-20 3e8352e Broaden internal CJK coverage
2026-03-12 4fdb790 Refresh status docs and tighten stale comments
2026-03-12 cae482d Clarify rich bidi metadata and share diagnostics
2026-03-12 45679aa Make emoji correction lazy for plain text
2026-03-11 a9652fd Add a batch low-level line geometry API
2026-03-11 90f1624 Add an editorial reflow demo and carry CJK opening punctuation
2026-03-11 57964f9 Add corpus taxonomy tooling
2026-03-10 f06fb75 Extract the internal line-break core
2026-03-10 614dfab Add a line-by-line reflow API and contour demo
2026-03-10 d782b14 Add explicit locale control for text analysis
2026-03-10 a734f17 Expose discretionary hyphen state to userland renderers
2026-03-10 c4cf982 Split prepare internals and add a second Japanese canary
2026-03-10 da60460 Split benchmark prepare timings by phase
2026-03-10 e30c04e Extract bidi logic from layout
2026-03-10 830d8ad Add a Japanese prose canary and fix iteration marks
2026-03-10 93b10a6 Keep bidi metadata off the fast prepare path
2026-03-10 c94b2ba Improve SHY diagnostics and line rendering
2026-03-10 b89a7fb Make layout imports safe outside the DOM
2026-03-10 b6e2104 Finish the Myanmar phrase-glue canary
2026-03-10 c9cbfca Tighten Myanmar punctuation glue and probe diagnostics
2026-03-10 5e92358 Make prepare() return an opaque handle
2026-03-10 86f741f Refine mixed app-text breaking and diagnostics
2026-03-10 7995c72 Add a mixed app-text canary and glue URL runs
2026-03-10 d9f9873 Model discretionary soft hyphen breaks
2026-03-10 c340d09 Cache richer segment metrics during prepare
2026-03-10 62b258a Strengthen break semantics beyond plain spaces
2026-03-09 d988bb0 Keep layout on a specialized fast path
2026-03-09 3e991df Share line breaking between layout APIs
2026-03-09 4715123 Add Thai stress corpus and fix ASCII quote wrapping
2026-03-09 49e0f36 Loosen non-Safari edge tolerance for remaining Arabic fits
2026-03-09 8aaf7b8 Keep Arabic punctuation-plus-mark clusters with their word
2026-03-09 9612485 Refine Arabic preprocessing around punctuation and marks
2026-03-09 d91a0af Merge Arabic no-space punctuation clusters
2026-03-08 7fb726d Fingerprint browser test environments and fix Korean quote wraps in Chromium
2026-03-08 16c04fe Improve Arabic and Hindi corpus wrapping
2026-03-08 c852293 Simplify merged segmentation and CJK measurement
2026-03-08 06e6437 Keep apostrophe-led elisions with the following word
2026-03-08 3f9cb1e Separate prepare analysis from measurement
2026-03-07 8f4ac00 Harden browser-accuracy diagnostics without slowing layout
2026-03-07 9af7f63 Close the remaining browser accuracy gaps cheaply
2026-03-07 5cd5762 Add Gatsby diagnostics without regressing hot-path layout
2026-03-07 d07dd7a gatsby test: first pass
2026-03-07 89ed442 Document public layout data fields
2026-03-06 7a4f827 Make lineHeight an explicit layout-time input
2026-03-06 0aca7b6 Link system-ui warnings to RESEARCH.md exploration
2026-03-06 fea1fa7 Split fast and rich layout APIs
2026-03-06 dbebb7d Clean up stale docs and unify test data
2026-03-04 5ecce72 Simplify layout code: flatten data, remove dead computation, cut allocations
2026-03-04 76c2766 Update all docs for 4-font accuracy, clean up stale comments
2026-03-04 bad8fbc CJK-split all CJK segments, not just word-like — Firefox 99.7% → 99.9%
2026-03-04 573b6db Fix emoji correction for Safari — compare canvas vs DOM, not fontSize
2026-03-03 e2f1321 Document char-level experiment, prior art, fix text-layout repo URL
2026-03-03 fee6750 Opening bracket forward-merge, CSS config docs, Chrome 3838/3840
2026-03-03 aff5ba7 Benchmark CJK scaling, cleanup for...of, --no-hmr, NaN guard
2026-03-03 ae466fa Hoist word segmenter to module level, add TODO section
2026-03-03 e8de24c Fix prepare() perf regression: skip emoji grapheme scan for non-emoji text
2026-03-03 315658b Document cache design decision, slim down CLAUDE.md
2026-03-03 6ce9982 Kinsoku shori — CJK line-breaking rules, Chrome 99.7% → 99.9%
2026-03-03 91304c0 Emoji correction, merging fix, overflow handling — Chrome 99.4% → 99.7%
2026-03-03 f54a344 Revert trailing space experiment — restore Chrome 99.4%
2026-03-03 73783d0 Add line-break diagnostic, document Safari CSS behavior differences
2026-03-03 820e8e1 Add comments documenting motivations throughout
2026-03-03 f962f72 Initial project setup
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc 'cd /Users/maxgeorgopoulos/Documents/experiments/pretext && git show --stat --oneline --no-patch 3e991df d988bb0 f06fb75 cfdc371 a28df8c d18bb75 38c7090 8e305a7 39b38e5 0f889e6'
Chunk ID: fdbc05
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 139
Output:
3e991df Share line breaking between layout APIs
d988bb0 Keep layout on a specialized fast path
f06fb75 Extract the internal line-break core
cfdc371 Add preserve-spaces whitespace mode
a28df8c Rewrite whitespace mode around pre-wrap chunks
d18bb75 Restore simple layout fast path
38c7090 Split simple rich line walking from pre-wrap path
8e305a7 (origin/preserve-whitespace) Only compute prefix widths when the browser needs them
39b38e5 Add rich line round-trip invariants
0f889e6 Route Gatsby through corpus tooling and fix stale pending breaks
```
## Assistant
**Result** (success):
```
Command: /bin/zsh -lc "cd /Users/maxgeorgopoulos/Documents/experiments/pretext && sed -n '1,240p' thoughts.md"
Chunk ID: bfa6a3
Wall time: 0.0000 seconds
Process exited with code 0
Original token count: 548
Output:
## Personal Thoughts, In No Particular Order
- My personal desire is to see end-developers being empowered to make all the layouts that makes UI more expressive, without sacrificing maintainability & performance, and without having to wait for permissions from the web committee. The current UI stereotypes across all platforms has been either:
- a landing-page with few, floating text chunks, powered by GL
- a blog article with mostly just text and no possible interactivity
- a SaaS dashboard
- a mobile UI with 2-3 rectangles' worth of UI
- If you dig deep enough, 80% of CSS spec could be avoided if userland had better control over text. The paradigm of web layout shoves our text into a single-direction black hole, and to crawl those text metrics back incurs huge maintenance and performance overhead (ask AI about this).
- The convenience angle of CSS is gradually being eroded by the fact that:
- the more CSS expressivity we bake in, the worse the CSS perf becomes (against all wishes from everyone on the committee and userland), and "programming" in CSS (as opposed to just "declare things" in CSS) is something very few desire
- AI alleviates the need of having more hard-coded CSS configs, which are becoming more dictionary-like rather compositional.
- It's very hard to have new competing web browser implementations, because the specs are gigantic, and many engines (grassroot efforts, gamers-driven rewrites, languages-driven rewrites, etc.) eagerly chase & premature perf improvements before realizing that the specs, often written decades ago and disregarding modern perf & feature needs, throw a wrench in those architectures. As a first approximation, UI performance & developer ergonomics _cannot_ possibly have an order of magnitude improvement, because the bottleneck is in the specs themselves. The only way to circumvent this is to bring more capabilities to userland, in a hope to stop the spec from over-growing even more in the future. Stopping spec complexity is something every browser vendor can agree on (and ironically, sometime for completely opposing reasons).
- The cost of any verifiable software will trend toward 0
```
## Assistant
I’ve finished the core source, the tests, the benchmark/accuracy harnesses, the demos that actually exercise the abstraction, and the commit history arc. What remains is synthesis: what this *actually* is in system terms, what it unlocks, and where its ceiling still is.
## Assistant
### Tool: update_plan
**Args:**
```json
{
"explanation": "Completed a full read of the core engine, tests, diagnostics, demos, and git history. The remaining task is synthesis into a first-principles analysis of the mechanism, its place in web text history, and the design space it opens.",
"plan": [
{
"status": "completed",
"step": "Clone/open the Pretext repo and map the codebase structure"
},
{
"status": "completed",
"step": "Read implementation files and build a mental model of the rendering pipeline"
},
{
"status": "completed",
"step": "Inspect git history to understand design evolution and abandoned directions"
},
{
"status": "completed",
"step": "Research primary historical sources on web text rendering and related browser primitives"
},
{
"status": "in_progress",
"step": "Synthesize first-principles analysis of capabilities, constraints, and speculative possibilities"
}
]
}
```
## Assistant
**Result** (success):
```
Plan updated
```
## Assistant
Pretext is not fundamentally a text renderer. It is a **paragraph compiler plus a line-break query engine**. It factors browser text layout into a width-independent compile step and a width-dependent arithmetic step: `prepare()` analyzes and measures once, then `layout()`, `walkLineRanges()`, and `layoutNextLine()` answer geometry questions without going back through DOM layout. The README says this plainly, but the code makes the deeper point: the project is trying to extract the separable part of the browser’s inline formatting context and hand it to userland. ([raw.githubusercontent.com](https://raw.githubusercontent.com/chenglou/pretext/main/README.md))
Historically, the web kept paragraph layout inside the browser. CSS2.1 defines line boxes, their heights via `line-height`, and how inline boxes split across lines; floats can change the available width of each line. CSS Text later formalized `pre-wrap`, soft wrap opportunities, dictionary-dependent scripts, and `overflow-wrap`, while CSS Shapes only extends float wrapping and still keeps it tied to floats and one-sided flow. Canvas exposed `measureText()`, but only for a text run, not full multiline layout; DOM APIs like `getBoundingClientRect()` and `offsetHeight` expose results after layout, and read-after-write patterns can force synchronous layout. `Intl.Segmenter` finally exposed locale-sensitive grapheme/word segmentation. Pretext sits exactly in the crack between those primitives. ([w3.org](https://www.w3.org/TR/2010/WD-CSS2-20101207/css2.pdf))
The first-principles insight is this: **the hard part is not counting lines; the hard part is making text width additive enough that line counting becomes arithmetic**. Most of [analysis.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/analysis.ts#L321) is devoted to exactly that. It normalizes whitespace, classifies break kinds, and then reshapes `Intl.Segmenter` output into more stable semantic units: URLs and query strings, numeric expressions, ASCII punctuation chains, CJK kinsoku cases, Arabic no-space punctuation clusters, Myanmar glue, escaped quotes, zero-width breaks, soft hyphens, and `pre-wrap` chunks. This file is really a “layout semantics compiler” whose job is to turn browser text behavior into something locally composable. [analysis.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/analysis.ts#L49) [analysis.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/analysis.ts#L321) [analysis.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/analysis.ts#L413) [analysis.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/analysis.ts#L535) [analysis.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/analysis.ts#L783) ([raw.githubusercontent.com](https://raw.githubusercontent.com/chenglou/pretext/main/RESEARCH.md))
Then [measurement.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/measurement.ts#L27) does something very disciplined. It does not try to become HarfBuzz or a browser engine. It chooses an `OffscreenCanvas` or DOM canvas context, caches per-font segment metrics, lazily expands grapheme widths only when intra-word breaking might matter, and adds tiny empirical engine shims: Safari gets different fit policy, Chromium gets a CJK quote carry rule, and emoji correction is calibrated with one DOM comparison per font. That means Pretext’s claim is not “pure Unicode truth”; it is “browser-grounded enough to be useful, then patched only where reality forces it.” [measurement.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/measurement.ts#L11) [measurement.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/measurement.ts#L65) [measurement.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/measurement.ts#L123) [measurement.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/measurement.ts#L174) ([raw.githubusercontent.com](https://raw.githubusercontent.com/chenglou/pretext/main/RESEARCH.md))
The core compiled artifact lives in [layout.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/layout.ts#L83). This is the real intellectual center of the repo. `prepareInternal()` turns analyzed text into a width-independent IR: segment widths, break kinds, optional grapheme widths, optional prefix widths, discretionary hyphen width, tab stop advance, hard-break chunks, and two especially important arrays: `lineEndFitAdvances` and `lineEndPaintAdvances`. That split is subtle and crucial. Pretext distinguishes what should count when deciding whether a line still fits from what should actually be painted if the line ends there. That is why ordinary collapsed spaces can hang invisibly, preserved spaces can remain visible in `pre-wrap`, and tabs can paint without falsely tightening fit. [layout.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/layout.ts#L191) [layout.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/layout.ts#L321) [layout.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/layout.ts#L424) ([raw.githubusercontent.com](https://raw.githubusercontent.com/chenglou/pretext/main/README.md))
The actual line-breaking engine is [line-break.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/line-break.ts#L1). It has two kernels: a simple fast path for ordinary text, and a richer path for tabs, preserved spaces, hard breaks, soft hyphens, and engine quirks. The general path tracks the current line, the last admissible break, separate fit and paint widths, dynamic tab-stop advances, and chunk boundaries for hard breaks. `layoutNextLineRange()` is the deepest API in the repo: it turns a paragraph into a resumable stream over logical segment/grapheme cursors. That is the point where text stops being a black-box block and starts becoming a routed medium. [line-break.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/line-break.ts#L34) [line-break.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/line-break.ts#L102) [line-break.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/line-break.ts#L375) [line-break.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/line-break.ts#L673) ([raw.githubusercontent.com](https://raw.githubusercontent.com/chenglou/pretext/main/README.md))
Bidi is tellingly demoted. [bidi.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/src/bidi.ts#L1) computes segment levels only for the rich/custom-rendering path; the hot height-prediction path never touches them. That tells you exactly what Pretext is and is not trying to own. It wants to own **wrap geometry in logical text order**. It does not want to become a full visual-order text renderer, caret engine, or editing system.
The deepest unlock is not “measure text faster”. It is **making text layout queryable enough that other algorithms can sit above it**. In the code, [pages/demos/masonry/index.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/pages/demos/masonry/index.ts#L34) uses `layout()` as a card-height oracle for virtualization-friendly masonry, [pages/demos/bubbles-shared.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/pages/demos/bubbles-shared.ts#L61) binary-searches multiline shrinkwrap, [pages/demos/dynamic-layout.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/pages/demos/dynamic-layout.ts#L275) and [pages/demos/editorial-engine.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/pages/demos/editorial-engine.ts#L402) stream a single paragraph through varying-width slots around polygons, logos, and moving obstacles, [pages/demos/rich-note.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/pages/demos/rich-note.ts#L189) composes styled inline fragments, and [pages/demos/justification-comparison.model.ts](/Users/maxgeorgopoulos/Documents/experiments/pretext/pages/demos/justification-comparison.model.ts#L123) treats Pretext as a substrate for higher-order paragraph optimization. That is the category change. ([raw.githubusercontent.com](https://raw.githubusercontent.com/chenglou/pretext/main/README.md))
Seen from first principles, text is the major entropy source in UI layout. Boxes without text are easy. Text makes heights unknown, widths unstable, and layout state hidden inside the engine. Pretext does not replace Grid or Flexbox; it removes one of the main reasons you need to ask the browser for permission in the first place. That is why the README’s examples about virtualization, masonry, shrinkwrap, and manual reflow are not separate features. They are all consequences of the same factorization:
```text
(text, font, locale, white-space mode, browser profile)
-> prepared paragraph IR
prepared paragraph IR + width
-> line ranges
line ranges + lineHeight
-> block height / positioned lines
```
([raw.githubusercontent.com](https://raw.githubusercontent.com/chenglou/pretext/main/README.md))
What it does **not** fundamentally unlock is just as important. It is not a full typesetter. It does not own glyph placement, baseline math, justification, font fallback policy, vertical writing, ruby, selection geometry, caret mapping, full bidi visual reordering, `system-ui` correctness, or universal browser-independent exactness. The research log is blunt that DOM measurement in the hot path, SVG measurement, pair-correction models, generic rescaling, and HarfBuzz as runtime center were all rejected. The remaining canaries are exactly where additivity breaks: `system-ui` resolution mismatches, emoji canvas/DOM drift, and shaping/context-sensitive scripts like Urdu and Myanmar, plus fine-width Chinese/Japanese edge fields. That is the structural ceiling of this approach: it wins by approximating multiline layout from locally measured units, and locally measured units eventually stop being truly local. [RESEARCH.md](/Users/maxgeorgopoulos/Documents/experiments/pretext/RESEARCH.md) ([raw.githubusercontent.com](https://raw.githubusercontent.com/chenglou/pretext/main/RESEARCH.md))
The git history is unusually revealing. The repo starts monolithic, briefly carries HarfBuzz research, then repeatedly simplifies and stages itself: flatten arrays, split fast and rich APIs, separate analysis from measurement, extract `line-break.ts`, move bidi off the hot path, make the public prepared handle opaque, add `layoutNextLine()`, then add `pre-wrap` while restoring the simple fast path. The architecture keeps converging on one idea: **specialize the hot path, push complexity earlier, and expose the richer geometry only where it buys new layout powers**. That is why the repo spends so much more code on preprocessing, diagnostics, corpora, and probes than on the raw line loop.
The wild possibilities, from the mechanism rather than the marketing, are these:
- A UI compiler can search thousands of candidate widths, font sizes, and column counts and choose layouts by actual paragraph fit rather than CSS guesswork.
- A subtitle or caption engine can route text around detected faces and objects every frame instead of just moving a rectangle.
- A collaborative editor can hand one logical paragraph cursor through columns, annotations, widgets, avatars, and live cursors without splitting the source text.
- A design-system linter or AI agent can prove that every localized label stays within one line or a target height before shipping.
- A map or diagram can lay labels around routes, regions, and nodes instead of on top of them.
- A WebGL or SVG scene can use browser-like wrapping without delegating paragraph geometry back to the DOM.
- A paragraph optimizer can search breakpoints for raggedness, rivers, widows/orphans, emphasis, or ad inventory because line breaks become explicit state.
- A responsive magazine can let images, logos, or physics bodies carve a width field while text stays live and selectable.
- A generative UI system can optimize not just boxes and colors, but the geometry of language itself.
- The really wild version is a “text field engine”: every `y` coordinate exposes a different allowed `x` interval, and paragraphs become streams routed through that field instead of blocks dropped into rectangles.
That last one is the real beyond-the-bottom insight. CSS gives you boxes and asks text to submit. Pretext gives you a programmable width field and asks text to flow.
I couldn’t run the Bun test suite in this shell because `bun` wasn’t available, so this is source-level and history-level analysis rather than live execution. If you want a second pass, the best follow-ups are: a commit-by-commit evolution map, a line-by-line walkthrough of the current engine, or a deeper essay on “programmable text geometry” as a missing primitive of the web.