MaxfieldLewin / phe

Poker hand evaluator

phe

Poker hand evaluator, a port of PokerHandEvaluator.

It's super fast even though still 3x slower than the C version it was ported from, but hey you can use this directly with Node.js or even in the browser.

It's fast, cause it's using a hash algorithm relying on masking and tables. However the table data isn't huge like I've seen in other projects. This is possible because flushes are considered separately from other rankings

I highly recommend reading the informative writeup on how this all works.

const { rankBoard, rankDescription } = require('phe')

const board = 'As Ks 4h Ad Kd'
const rank = rankBoard(board)
const name = rankDescription[rank]

console.log('%s is a %s', board, name)

As Ks 4h Ad Kd is a Two Pair

Installation

npm install phe

Table of Contents generated with DocToc

• API
  • evaluateCardCodes
  • evaluateCards
  • evaluateCardsFast
  • evaluateBoard
  • rankCards
  • rankCardsFast
  • rankCardCodes
  • rankBoard
  • setCardCodes
  • setStringifyCardCodes
  • ranks
  • rankDescription
  • handRank
  • rankCodes
  • suitCodes
  • stringifyCardCode
  • stringifyRank
  • stringifySuit
  • cardCode
  • cardCodes
  • boardCodes
• License

API

evaluateCardCodes

Evaluates the 5 - 7 card codes to arrive at a number representing the hand strength, smaller is better.

Parameters

• cards Array<Number> the cards, i.e. [ 49, 36, 4, 48, 41 ]

Returns Number the strength of the hand comprised by the card codes

evaluateCards

Evaluates the 5 - 7 cards to arrive at a number representing the hand strength, smaller is better.

Parameters

• cards Array<String> the cards, i.e. [ 'Ah', 'Ks', 'Td', '3c', 'Ad' ]

Returns Number the strength of the hand comprised by the cards

evaluateCardsFast

Same as evaluateCards but skips cards argument type check to be more performant.

Parameters

• cards

evaluateBoard

Evaluates the given board of 5 to 7 cards provided as part of the board to arrive at a number representing the hand strength, smaller is better.

Parameters

• board String the board, i.e. 'Ah Ks Td 3c Ad'

Returns Number the strength of the hand comprised by the cards of the board

rankCards

Evaluates the 5 - 7 cards and then calculates the hand rank.

Parameters

• cards Array<String> the cards, i.e. [ 'Ah', 'Ks', 'Td', '3c', 'Ad' ]

Returns Number the rank of the hand comprised by the cards, i.e. 1 for FOUR_OF_A_KIND (enumerated in ranks)

rankCardsFast

Same as rankCards but skips cards argument type check to be more performant.

Parameters

• cards

rankCardCodes

Evaluates the 5 - 7 card codes and then calculates the hand rank.

Parameters

• cardCodes Array<Number> the card codes whose ranking to determine

Returns Number the rank of the hand comprised by the card codes, i.e. 1 for FOUR_OF_A_KIND (enumerated in ranks)

rankBoard

Evaluates the given board of 5 to 7 cards provided as part of the board to and then calculates the hand rank.

Parameters

• board String the board, i.e. 'Ah Ks Td 3c Ad'

Returns Number the rank of the hand comprised by the cards, i.e. 1 for FOUR_OF_A_KIND (enumerated in ranks)

setCardCodes

Converts a set of cards to card codes.

Parameters

• set Set<String> card strings set, i.e. Set({'Ah', 'Ks', 'Td', '3c, 'Ad'})

Returns Set<Number> card code set

setStringifyCardCodes

Converts a set of card codes to their string representations.

Parameters

• set Set<Number> card code set

Returns Set<String> set with string representations of the card codes, i.e. Set({'Ah', 'Ks', 'Td', '3c, 'Ad'})

ranks

Enumeration of possible hand ranks, each rank is a number from 0-8.

STRAIGHT_FLUSH
FOUR_OF_A_KIND
FULL_HOUSE
FLUSH
STRAIGHT
THREE_OF_A_KIND
TWO_PAIR
ONE_PAIR
HIGH_CARD

rankDescription

Provides a description of a hand rank number. It's an {Array} which can be indexed into with the hand rank in order to retrieve the matching description.

Example: rankDescription[rank.FULL_HOUSE] === 'Full House'

handRank

Converts a hand strength number into a hand rank number 0 - 8 for STRAIGHT_FLUSH - HIGH_CARD.

Parameters

• val Number hand strength (result of an evaluate function)

Returns Number the hand rank

rankCodes

The ranks of the cards sorted highest to lowest.

• 2 = 0
• 3 = 1
• 4 = 2
• 5 = 2
• 6 = 4
• 7 = 5
• 8 = 6
• 9 = 7
• T = 8
• J = 9
• Q = 10
• K = 11
• A = 12

6 bits each.

Returns Object the ranks indexed as described above

suitCodes

The suitCodes

• s = 0
• h = 1
• d = 2
• c = 3

Returns Object the suits indexed as described above

stringifyCardCode

Converts the given card code into a string presentation.

Parameters

• code Number the card code, i.e. obtained via cardCode(rank, suit).

Returns String a string representation of the card in question, i.e. Ah

stringifyRank

Converts the given rank index into a rank.

Parameters

• rank Number the rank to stringify, i.e. 0b000100

Returns String the string of the rank, i.e. '2'

stringifySuit

Converts the given suit index to a suit.

Parameters

• suit Number the suit to stringify, i.e. 0b1

Returns String the string of the sut, i.e. 'c' (clubs)

cardCode

Determines the code for the given hand.

Parameters

• rank String the rank of the hand, i.e. A
• suit String the suit of the hand, i.e. h

Returns Number the card code that can be used to further evaluate the hand

cardCodes

Determines the code for the given hands.

Parameters

• cards Array<String> the cards to convert into card codes, i.e. [ 'Ah', 'Kd' ]

Returns Array<Number> the card codes that can be used to further evaluate the hands

boardCodes

Determines the code for the given hands.

Parameters

• board String the board to convert into card codes, i.e. 'Ah Kd Qh'

Returns Array<Number> the card codes that can be used to further evaluate the hands

License

MIT