mj

What is this?

mj is a Mahjong-solving library. Currently it can tell you the best grouping of tiles in a hand as well as some winning conditions.

You can try handcheck in your browser. Source code for the Go WASM entry point is at cmd/handcheck_wasm_tinygo and the Web frontend at assets_tinygo.

It targets Go 1.16 and builds under official Go and tinygo. Tinygo is recommended for the wasm version due to smaller code size.

Benchmarking

Performance of the checkers on certain degenerate hands.

• HandRLE: the run-length encoded hand representation
• Count: the map[Tile]int hand representation
• AllP: b1 b1 b1 b1 b1 b1 b1 b1 b1 b1 b1 b1 b1 b1 (cannot occur in the course of the game)
• AllPReal: b1 b1 b1 b2 b2 b2 b3 b3 b3 b4 b4 b4 b5 b5 (can occur)
• AllC: b1 b2 b3 b3 b4 b5 b5 b6 b7 b7 b8 b9 b9 b9
• NS: w1 b7 w4 c5 b9 he w5 hf w5 c3 b8 hf hn hf (plausible hand)

HandRLE is faster. Maps are not the best way to represent the small number of tiles in each hand.

HandRLE: range Entries

Benchmark_OptHandRLEChecker_AllP-12                96655             11118 ns/op            4669 B/op        217 allocs/op
Benchmark_OptHandRLEChecker_AllPReal-12             2239            561164 ns/op          188182 B/op       8412 allocs/op
Benchmark_OptHandRLEChecker_AllC-12                 4593            262267 ns/op           93175 B/op       3743 allocs/op
Benchmark_OptHandRLEChecker_NS-12                  66718             17722 ns/op            6702 B/op        232 allocs/op
PASS
ok      github.com/nik0sc/mj/handcheck  5.618s

HandRLE: ForEach

Benchmark_OptHandRLEChecker_AllP-12                99618             11184 ns/op            4620 B/op        204 allocs/op
Benchmark_OptHandRLEChecker_AllPReal-12             2235            534924 ns/op          183853 B/op       8115 allocs/op
Benchmark_OptHandRLEChecker_AllC-12                 4620            249328 ns/op           89256 B/op       3580 allocs/op
Benchmark_OptHandRLEChecker_NS-12                  70348             16978 ns/op            6230 B/op        220 allocs/op
PASS
ok      github.com/nik0sc/mj/handcheck  5.433s

Counter: range Entries

Benchmark_OptCountChecker_AllP-12                  52147             21158 ns/op            9661 B/op        328 allocs/op
Benchmark_OptCountChecker_AllPReal-12                864           1382612 ns/op          417036 B/op      14509 allocs/op
Benchmark_OptCountChecker_AllC-12                   1599            755546 ns/op          190976 B/op       6313 allocs/op
Benchmark_OptCountChecker_NS-12                    21586             52459 ns/op           11393 B/op        344 allocs/op
PASS
ok      github.com/nik0sc/mj/handcheck  6.039s

Counter: ForEach

Benchmark_OptCountChecker_AllP-12                  53492             21314 ns/op            9660 B/op        328 allocs/op
Benchmark_OptCountChecker_AllPReal-12                874           1387995 ns/op          417039 B/op      14509 allocs/op
Benchmark_OptCountChecker_AllC-12                   1570            761786 ns/op          190933 B/op       6312 allocs/op
Benchmark_OptCountChecker_NS-12                    22988             51988 ns/op           11393 B/op        344 allocs/op
PASS
ok      github.com/nik0sc/mj/handcheck  5.797s