Evaluating Rust Files and Project RoadmapPublic

Let me survey the Rust source files to identify candidates based on size and complexity.

The clear standout is game.rs at nearly 14K lines. Let me look at its internal structure to understand what could be split.

Here's the picture:

Analysis

game.rs is the clear candidate — 13,870 lines, and it's the only file that's unwieldy. Everything else is reasonably sized (the set files are large but inherently repetitive card listings).

Breaking game.rs down:

The biggest functions in the core logic:

There are also 3 duplicate AlwaysPassPlayer impls in different test modules.

Recommendations

Splits that would help:

1. Move tests out of game.rs (~9K lines) — The 38 test modules could live in mtg-engine/tests/ as integration tests, or in a game/ module directory with a separate tests.rs. This alone would cut the file from 14K to ~5K lines.

2. Extract execute_effects() into game/effect_resolution.rs (~1,600 lines) — This is a massive match statement. It's a natural unit: "given an Effect enum variant, modify game state." Could be impl Game in a separate file via the mod pattern.

3. Extract combat into game/combat_resolution.rs (~350 lines) — declare_attackers_step, declare_blockers_step, combat_damage_step, resolve_fight_pair form a cohesive group.

4. Extract apply_continuous_effects + filter/matching helpers (~400 lines) — apply_continuous_effects, matches_filter, card_matches_filter, find_matching_permanents are a natural cluster.

Splits that are probably NOT worth it:

• The set card files (fdn.rs etc.) — they're big but dead-simple repetitive factories; splitting by letter or rarity would add complexity without improving readability.
• abilities.rs (2,113 lines) — it's mostly enum definitions and builder methods, reads fine as-is.
• Any of the other engine files — all under 1K lines.

Bottom line: game.rs is doing the work of 3-4 files. The highest-impact move is extracting tests, then execute_effects. Want me to plan and do one of these splits?