gogame.js

gogame.js is a headless JavaScript Go (Baduk/Weiqi) library used for move generation/validation, capture detection, and area scoring - basically everything but the AI.

gogame.js has been extensively tested in Node.js and modern browsers.

Installation

npm install gogame.js

Importing

Import (as ESM)

import { Go } from 'gogame.js'

Import (as CommonJS)

const { Go } = require('gogame.js')

Example Code

The code below plays a random game of Go on a 9x9 board:

import { Go } from 'gogame.js'
const game = new Go(9)

while (!game.done) {
  // Logic to select a legal coordinate
  game.move('e5')
  game.move('pass')
  game.move('pass')
}

console.log(game.score())

User Interface

By design, gogame.js is a headless library and does not include user interface elements. It is intended to be used with a frontend board renderer.

API

Constructor: new Go([ size ], [ komi ])

Creates a new game instance.

• size (Integer, default: 19): The dimensions of the board.
• komi (Float, default: 6.5): Points added to White's score.

.ascii()

Returns a string containing an ASCII diagram of the current position.

const game = new Go(9)
game.move('e5')
console.log(game.ascii())

// ->   a b c d e f g h i
//    9 . . . . . . . . . 9
//    8 . . . . . . . . . 8
//    7 . . . . . . . . . 7
//    6 . . . . . . . . . 6
//    5 . . . . X . . . . 5
//    4 . . . . . . . . . 4
//    3 . . . . . . . . . 3
//    2 . . . . . . . . . 2
//    1 . . . . . . . . . 1
//      a b c d e f g h i

.board

Returns a flat 1D array representation of the current position. Empty squares are null.

const game = new Go(9)
game.board
// -> [null, null, 'B', null, ...]

.clear()

Clears the board.

game.clear()

.get(square)

Returns the piece on the square. Returns null if the square is empty.

game.move('e5')
game.get('e5')
// -> 'B'

.move(square)

Executes a move on the board.

• square: The algebraic notation (e.g., 'e5') or 'pass'.
• Returns: A move object on success, or null if the move is illegal (occupied, suicide, or superko).

game.move('e5')
// -> { col: 'B', sq: 'e5', caps: 0, board: [...] }

.score()

Calculates the current score based on Area rules.

• Returns: { B: Number, W: Number }

game.score()
// -> { B: 12, W: 18.5 }

.turn

Returns the current player whose turn it is ('B' or 'W').

.done

A boolean indicating if the game has ended via two consecutive passes.

Technical Specifications

Coordinate System

gogame.js uses a standard algebraic coordinate system where the X-axis is represented by letters (a-z) and the Y-axis by numbers (1-n).

Positional Superko

This library implements the Positional Superko rule. A move is illegal if it results in a board state that has occurred previously in the game.

Scoring

gogame.js uses Area Scoring (Chinese/AGA standard), counting stones on the board plus surrounded empty intersections.

License

MIT