Riichi Mahjong Scoring Library and Calculator

CLI tool that calculates the score of a hand in riichi mahjong.

• Manual mode (Calculator Mode): given han and fu, calculates the score
• Normal mode: given a hand, calculates the score with included yaku and fu

This also doubles as a scoring library! checkout out the docs on crates.io

Examples

Library Usage

use mahc::tile_group::TileGroup;
use mahc::tile::Tile;
use mahc::tile::Wind;
use mahc::hand::Hand;

// creating a tilegroup from a string
let one_two_three_seq: TileGroup = "123s".to_string().try_into().unwrap();
let seven_eight_nine_seq: TileGroup = "789m".to_string().try_into().unwrap

// creating a tilegroup from tiles
let seven_tile: Tile = "7m".to_string().try_into().unwrap();
let seven_pair: TileGroup =
    TileGroup::new(vec![seven_tile.clone(), seven_tile.clone()], false).unwrap();

// creating tiles in a few ways
let win_tile: Tile = "7m".to_string().try_into().unwrap();
let seat_wind: Tile = Tile::new(EAST_VALUE, &Suit::Wind).unwrap();
let prevelent_wind: Tile = Tile::Wind(WValue::West);

let hand = Hand::new(
    vec![
        one_two_three_seq.clone(),
        one_two_three_seq.clone(),
        seven_eight_nine_seq.clone(),
        seven_eight_nine_seq.clone(),
        seven_pair.clone(),
    ],
    win_tile,
    seat_wind,
    prevelent_wind,
)
.unwrap();
assert!(hand.is_ryanpeikou());

// get list of yaku, fu
let score = get_hand_score(
    &hand, &None, false, false, false, false, false, false, false, false, 0,
)
.unwrap();
assert_eq!(score.han(), 3);
assert_eq!(score.fu_score(), 40);

// get payment information
let payment = calculate(&score.han(), &score.fu_score()).unwrap();
assert_eq!(payment.base_points(), 1280);
assert_eq!(payment.dealer_ron(score.honba()), 7700);

Calculator Mode

~/$ mahc -m 4 30 --ba 3
> Dealer:    12500 (4200) 
  non-dealer: 8600 (2300/ 4200)

Normal Mode

note: the winning group has to go last (this is to calculate fu correctly)

~/$ mahc --tiles 777z 111z 234p 234p 11p -w 1p -p Ew -s Ew
> 7 Han/ 50 Fu
  Dealer: 18000 (6000)
  Non-dealer: 12000 (3000/6000)
  Yaku:
    Iipeikou: 1
    Honitsu: 3
    Yakuhai: 1
    Yakuhai: 1
    Yakuhai: 1
  
  Fu:
    BasePoints: 20
    ClosedRon: 10
    NonSimpleClosedTriplet: 8
    NonSimpleClosedTriplet: 8
    SingleWait: 2

Using file input

# hands.txt
--tiles 1p 9p 1s 9s 1m 9m rd gd wd Ew Sw Nw WWw -w Ww -p Ew -s Ew
--tiles 11z NNw SSw WWw rrd wwd ggd -w gd -p Ew -s Ew -d Ew Ew
-m 4 30 --ba 3

~/$ mahc -f hands.txt

❯ Dealer: 96000 (32000)
  Non-dealer: 64000 (16000/32000)
  Yaku:
    KokushiMusou Yakuman
    KokushiMusou Yakuman 13 sided wait
  
  Dealer: 144000 (48000)
  Non-dealer: 96000 (24000/48000)
  Yaku:
    Tsuuiisou Yakuman
    Daichiishin Yakuman
    Shousuushii Yakuman
  
  4 Han/ 30 Fu/ 3 Honba
  Dealer: 12500 (4200)
  non-dealer: 8600 (2300/4200)

Json out

in normal mode

~/$ mahc --tiles 123p 456p 789p rrrdo 99p -w 9p -p Ew -s Ew -d 9p --json

yields

{
    "dora":1,
    "fu":30,
    "fuString":[ "BasePoints: 20", "NonSimpleOpenTriplet: 4", "SingleWait: 2"
    ],
    "han":5,
    "honba":0,
    "scores":{
        "dealer":{"ron":12000,"tsumo":4000},
        "non-dealer":{
            "ron":8000, 
            "tsumo":{"dealer":4000,"non-dealer":2000}
        }
    },
    "yakuString":["Honitsu: 2","Ittsuu: 1","Yakuhai: 1"]
}

and in calculator mode

~/$ mahc -m 4 30 --ba 3 --json

yields

{
    "fu":30,
    "han":4,
    "honba":3,
    "scores":{
        "dealer":{ "ron":12500, "tsumo":4200 },
        "non-dealer":{ "ron":8600, "tsumo":{ "dealer":4200, "non-dealer":2300 }
        }
    }
}

Notation

Suits

Honors

Special Notation

• eg: EEEw (triplet of east wind)
• eg: 234m (sequence of 2 3 4 Man)
• eg: 406s (sequence of 4 5 6 Sou with the akadora 5 sou)
• eg: rrrrdo (open quad of red dragon)
• eg: 11s (pair of 1 sou)
• eg: 8m (8 man tile)

Installation

using cargo

cargo install mahc
mahc --version

build from source

git clone https://github.com/DrCheeseFace/mahc
cd mahc
cargo build
./target/debug/mahc --version

from latest release

curl -s https://api.github.com/repos/DrCheeseFace/rusty-riichi-mahjong-calculator/releases/latest | grep "browser_download_url" | cut -d '"' -f 4 | wget -i -
unzip mahc-v1.1.0-x86_64-unknown-linux-gnu.zip -d mahc
cd mahc/x86_64-unknown-linux-gnu/release
./mahc --version

Implemented hand validations as of yet

One Han Yaku

• Tanyao
• Iipeikou
• Yakuhai
• MenzenTsumo
• Pinfu
• Riichi
• Ippatsu
• Haitei
• RinshanKaihou
• Chankan

Two Han Yaku

• DoubleRiichi
• Toitoi
• Ittsuu
• SanshokuDoujun
• Chantaiyao
• Sanankou
• SanshokuDoukou
• Sankantsu
• Honroutou
• Shousangen
• Chiitoitsu

Three Han Yaku

• Honitsu
• JunchanTaiyao
• Ryanpeikou

Six Han Yaku

• Chinitsu

Yakuman

• KazoeYakuman
• KokushiMusou
• KokushiMusou 13 sided wait
• Suuankou
• Suuankou tanki wait
• Daisangen
• Shousuushii
• Daisuushii
• Tsuuiisou
• Daiichishin
• Chinroutou
• Ryuuiisou
• ChuurenPoutou
• ChuurenPoutou 9 sided wait
• Suukantsu
• Tenhou
• Chiihou

TODO

• validation a hand is possible (eg not having 20 east tiles :)
• add all da yaku
• validation on if yaku is there
• validate winning tile
• propogate the errors up for a nice printout
• validate stuff like cant riichi and double riichi. all that haitei, chankan rinshan shizz
• file stdIn
• json out flag
• tile input for --dora flag
• add more comprehensive tests
• document the undocumented

Contributing

• ---- @gondoly @GuoDCZ

• If you spot a bug (which there probabably are many), put in an issue with how to reproduce it

• if youd like to contribute, DO IT (send a PR)