The Great Analysis Challenge: Multi-Language Chess Engine Project

Polyglot chess engine benchmark: same functional spec, multiple language implementations, Docker-first workflow, shared tests.

Documentation

Start here: Documentation Hub

Core references:

• CHESS_ENGINE_SPECS.md - authoritative engine and CLI requirements
• AI_ALGORITHM_SPEC.md - minimax + alpha-beta deterministic behavior
• AGENTS.md - agent operating rules for this repository
• llms.txt - compact file map for LLM tooling

Available Implementations

All implementations target parity for core features: perft, fen, ai, castling, en_passant, promotion.

Language	Complexity	LOC	make build	make analyze	make test	make test-chess-engine	Features
📦 C	7,151.5	2,406	925ms, - MB	187ms, - MB	913ms, - MB	18.1s, - MB	🟢 9/9
💠 Crystal	8,040.5	3,308	1.4s, - MB	198ms, - MB	4.4s, - MB	18.8s, - MB	🟢 9/9
🎯 Dart	15,055.25	5,006	634ms, - MB	507ms, - MB	564ms, - MB	20.5s, - MB	🟡 9/9
💧 Elixir	5,312.75	2,084	612ms, - MB	1s, - MB	627ms, - MB	21.4s, - MB	🟢 9/9
🌳 Elm	5,109.75	1,811	184ms, - MB	180ms, - MB	187ms, - MB	20.1s, - MB	🟢 9/9
✨ Gleam	28,222.5	4,275	211ms, - MB	301ms, - MB	443ms, - MB	19.7s, - MB	🟢 9/9
🐹 Go	15,016.25	5,703	586ms, - MB	1s, - MB	1.2s, - MB	25.3s, - MB	🟢 9/9
📐 Haskell	8,143.25	2,312	291ms, - MB	496ms, - MB	153ms, - MB	21.1s, - MB	🟢 9/9
🪶 Imba	6,167	1,708	442ms, - MB	455ms, - MB	143ms, - MB	19.7s, - MB	🟡 9/9
🟨 Javascript	4,396.5	1,602	<1ms, - MB	160ms, - MB	188ms, - MB	41s, - MB	🟢 9/9
🔮 Julia	5,997.25	2,083	<1ms, - MB	962ms, - MB	3.4s, - MB	22.2s, - MB	🟡 9/9
🧡 Kotlin	6,774	1,974	8.7s, - MB	8.5s, - MB	214ms, - MB	20.9s, - MB	🟡 9/9
🪐 Lua	15,254.25	4,192	<1ms, - MB	148ms, - MB	161ms, - MB	32.7s, - MB	🟢 9/9
🦊 Nim	7,067	1,636	798ms, - MB	738ms, - MB	128ms, - MB	18.7s, - MB	🟢 9/9
🐘 Php	18,067.25	5,879	<1ms, - MB	410ms, - MB	170ms, - MB	24.7s, - MB	🟢 9/9
🐍 Python	12,581.25	4,978	<1ms, - MB	222ms, - MB	1.9s, - MB	42s, - MB	🟡 9/9
🧠 Rescript	6,827.75	2,381	364ms, - MB	586ms, - MB	224ms, - MB	22.3s, - MB	🟡 9/9
❤️ Ruby	5,466	2,469	<1ms, - MB	2.5s, - MB	315ms, - MB	19.2s, - MB	🟡 9/9
🦀 Rust	9,721.75	2,834	182ms, - MB	512ms, - MB	777ms, - MB	18.2s, - MB	🟢 9/9
🐦 Swift	5,497.5	1,506	1.7s, - MB	7.9s, - MB	10.3s, - MB	18.3s, - MB	🟢 9/9
📘 Typescript	7,773.5	2,586	2s, - MB	3.5s, - MB	2.2s, - MB	24.7s, - MB	🟡 9/9
⚡ Zig	13,193	2,509	208ms, - MB	149ms, - MB	142ms, - MB	34.8s, - MB	🟢 9/9

Legend:

• Features: 🟢/🟡/🔴 status badge followed by implemented features count from metadata, e.g. 🟡 6/9.
• Complexity: weighted tokens-v3 semantic complexity_score, linked to the implementation entrypoint.
• LOC: source lines of code from Git-discovered source files filtered by metadata org.chess.source_exts.
• make ... columns: <duration>, <peak memory>.
• -: metric missing or intentionally skipped.

Semantic Token Metrics (tokens-v3)

The README matrix uses the weighted complexity_score from tokens-v3. Raw tokens-v2 counts and the full semantic breakdown remain available in the versioned report JSON files and through the shared Bun tooling. These metrics are powered by Shiki and classify tokens into semantic categories while down-weighting punctuation and excluding comments from scoring.

Running semantic analysis

# Single implementation
bun run scripts/semantic-tokens/semantic_tokens.mjs implementations/rust --pretty

# All implementations
bun run scripts/semantic-tokens/semantic_tokens.mjs --all implementations/ --pretty

# Shared metrics pipeline (tokens-v2 + optional tokens-v3)
./workflow code-size-metrics --impl implementations/rust

# Refresh semantic metrics inside versioned reports
./workflow refresh-report-metrics

Complexity score

Category	Weight	Examples
keyword	1.0	if, fn, return, class
identifier	1.0	variables, functions, methods
type	1.0	type annotations, generics
operator	0.5	+, ==, &&, ->
literal	0.5	numbers, strings
punctuation	0.25	{}, (), ;, ,
comment	0.0	excluded from scoring
unknown	0.5	fallback classification

complexity_score = Σ(weight × count).

Quick Commands

make list-implementations
make image DIR=<language>
make build DIR=<language>
make analyze DIR=<language>
make test DIR=<language>
make test-unit-contract DIR=<language>
make test-chess-engine DIR=<language>
./workflow semantic-tokens implementations/<language> --pretty
./workflow refresh-report-metrics

All implementation build/test/analyze operations are Docker-only.