chehsunliu / poker

A pure Go library for poker hand evaluation.

Poker

Poker is ported from the Python library worldveil/deuces.

Installation

Use go get to install Poker:

$ go get github.com/chehsunliu/poker

Usage

Support 5-, 6-, and 7-card evalutions:

package main

import (
	"fmt"

	"github.com/chehsunliu/poker"
)

func main() {
	deck := poker.NewDeck()
	hand := deck.Draw(7)
	fmt.Println(hand)

	rank := poker.Evaluate(hand)
	fmt.Println(rank)
	fmt.Println(poker.RankString(rank))
}

$ go run ./main.go
[Kd 4h Qh 3s 8s 5h Jd]
6695
High Card

$ go run ./main.go
[4c Qh Ad 9c 9s 3h 4d]
3062
Two Pair

$ go run ./main.go
[Jh Qd Kd Qs 7d As Qh]
1742
Three of a Kind

Performance

Compared with notnil/joker, Poker is 160x faster on 5-card evaluation, and drops to 40x faster on 7-card evaluation.

go test -bench=. -benchtime 5s
goos: darwin
goarch: amd64
pkg: github.com/chehsunliu/poker
BenchmarkFivePoker-4    	23396181	       253 ns/op
BenchmarkFiveJoker-4    	  141036	     41662 ns/op
BenchmarkSixPoker-4     	 3037298	      1949 ns/op
BenchmarkSixJoker-4     	   28158	    211533 ns/op
BenchmarkSevenPoker-4   	  356448	     16357 ns/op
BenchmarkSevenJoker-4   	    7143	    759394 ns/op
PASS
ok  	github.com/chehsunliu/poker	40.111s

poker's Issues

wrong RankString for 7 cards evaluation

	hand := []poker.Card{
		poker.NewCard("Qh"),
		poker.NewCard("Kh"),
		poker.NewCard("Js"),
		poker.NewCard("2d"),
		poker.NewCard("Qd"),
		poker.NewCard("10d"),
		poker.NewCard("9s"),
	}
	e := poker.Evaluate(hand)
	fmt.Println(e, poker.RankString(e)) // 2821 Two Pair

For this hand, it says "Two Pair", I see one (Qh & Qd).