@sabaki/go-board
v1.4.3
Published
A Go board data type
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@sabaki/go-board
A Go board data type.
Installation
Use npm to install:
$ npm install @sabaki/go-board
Usage
const Board = require('@sabaki/go-board')
let board = new Board([
[ 0, 0, 0,-1,-1,-1, 1, 0, 1, 1,-1,-1, 0,-1, 0,-1,-1, 1, 0],
[ 0, 0,-1, 0,-1, 1, 1, 1, 0, 1,-1, 0,-1,-1,-1,-1, 1, 1, 0],
[ 0, 0,-1,-1,-1, 1, 1, 0, 0, 1, 1,-1,-1, 1,-1, 1, 0, 1, 0],
[ 0, 0, 0, 0,-1,-1, 1, 0, 1,-1, 1, 1, 1, 1, 1, 0, 1, 0, 0],
[ 0, 0, 0, 0,-1, 0,-1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0],
[ 0, 0,-1, 0, 0,-1,-1, 1, 0,-1,-1, 1,-1,-1, 0, 1, 0, 0, 1],
[ 0, 0, 0,-1,-1, 1, 1, 1, 1, 1, 1, 1, 1,-1,-1,-1, 1, 1, 1],
[ 0, 0,-1, 1, 1, 0, 1,-1,-1, 1, 0, 1,-1, 0, 1,-1,-1,-1, 1],
[ 0, 0,-1,-1, 1, 1, 1, 0,-1, 1,-1,-1, 0,-1,-1, 1, 1, 1, 1],
[ 0, 0,-1, 1, 1,-1,-1,-1,-1, 1, 1, 1,-1,-1,-1,-1, 1,-1,-1],
[-1,-1,-1,-1, 1, 1, 1,-1, 0,-1, 1,-1,-1, 0,-1, 1, 1,-1, 0],
[-1, 1,-1, 0,-1,-1,-1,-1,-1,-1, 1,-1, 0,-1,-1, 1,-1, 0,-1],
[ 1, 1, 1, 1,-1, 1, 1, 1,-1, 1, 0, 1,-1, 0,-1, 1,-1,-1, 0],
[ 0, 1,-1, 1, 1,-1,-1, 1,-1, 1, 1, 1,-1, 1,-1, 1, 1,-1, 1],
[ 0, 0,-1, 1, 0, 0, 1, 1,-1,-1, 0, 1,-1, 1,-1, 1,-1, 0,-1],
[ 0, 0, 1, 0, 1, 0, 1, 1, 1,-1,-1, 1,-1,-1, 1,-1,-1,-1, 0],
[ 0, 0, 0, 0, 1, 1, 0, 1,-1, 0,-1,-1, 1, 1, 1, 1,-1,-1,-1],
[ 0, 0, 1, 1,-1, 1, 1,-1, 0,-1,-1, 1, 1, 1, 1, 0, 1,-1, 1],
[ 0, 0, 0, 1,-1,-1,-1,-1,-1, 0,-1,-1, 1, 1, 0, 1, 1, 1, 0]
])
let move = board.makeMove(1, [9, 4])
API
Sign Map
The board arrangement is represented by an array of arrays. Each of those subarrays represent one row, all containing the same number of integers. -1
denotes a white stone, 1
a black stone, and 0
represents an empty vertex.
Example
[[ 0, 0, 1, 0,-1,-1, 1, 0, 0],
[ 1, 0, 1,-1,-1, 1, 1, 1, 0],
[ 0, 0, 1,-1, 0, 1,-1,-1, 0],
[ 1, 1, 1,-1,-1,-1, 1,-1, 0],
[ 1,-1, 1, 1,-1, 1, 1, 1, 0],
[-1,-1,-1,-1,-1, 1, 0, 0, 0],
[ 0,-1,-1, 0,-1, 1, 1, 1, 1],
[ 0, 0, 0, 0, 0,-1,-1,-1, 1],
[ 0, 0, 0, 0, 0, 0, 0,-1, 0]]
Vertex
Board positions are represented by a vertex, i.e. an array of the form [x, y]
where x
and y
are non-negative integers, zero-based coordinates. [0, 0]
denotes the upper left position of the board.
class Board
Constructors
new Board([signMap])
signMap
<SignMap>
(optional) - Default:[]
Board.fromDimensions(width[, height])
width
<Integer>
height
<Integer>
(optional) - Default:width
Returns a new Board
instance with a sign map of the given dimensions that is filled with 0
.
Properties
board.signMap
<SignMap>
- The underlying sign map of the board.
board.width
<Integer>
- The board width.
board.height
<Integer>
- The board height.
Stone Arrangement Functions
board.get(vertex)
vertex
<Vertex>
Returns the sign at the given vertex
.
board.set(vertex, sign)
vertex
<Vertex>
sign
<Integer>
- One of-1
,0
, or1
Sets the sign at the given vertex
. No validity checks will be made. This function mutates the board and returns this
to enable chaining.
board.has(vertex)
vertex
<Vertex>
Returns a boolean whether the given vertex
is valid or can be found on the board.
board.clear()
Sets the sign of all vertices to 0
. This function mutates the board and returns this
to enable chaining.
board.makeMove(sign, vertex[, options])
sign
<Integer>
- One of-1
,0
, or1
vertex
<Vertex>
options
<Object>
(optional)preventOverwrite
<Boolean>
- Default:false
preventSuicide
<Boolean>
- Default:false
preventKo
<Boolean>
- Default:false
Returns a new board instance that represents the board state after the player who corresponds to the given sign
makes a move at vertex
. The capture count will also be updated correctly. If board
is valid then the new returned board instance will also be valid. This function will not mutate board
. If sign
is 0
or vertex
not valid, this function will be equivalent to clone()
.
If preventOverwrite
is set to true
, this function will throw an error if the attempted move is on a vertex that is already occupied by a stone.
If preventSuicide
is set to true
, this function will throw an error if the attempted move is a suicide.
If preventKo
is set to true
, this function will throw an error if the attempted move repeats the position that led to board
.
board.analyzeMove(sign, vertex)
sign
<Integer>
- One of-1
,0
, or1
vertex
<Vertex>
Analyzes the hypothetical move that the player who corresponds to the given sign
would make at vertex
. Returns an object with the following keys with boolean values:
pass
- Specifies if the move would be a pass (sign
is0
orvertex
is not valid)overwrite
- Specifies if the move would overwrite an occupied stone on the boardcapturing
- Specifies if the move would capture some enemy stonesuicide
- Specifies if the move would end up in a suicideko
- Specifies if the move would repeat the position that led toboard
Capture Count Functions
board.getCaptures(sign)
sign
<Integer>
- One of-1
or1
Returns the number of stones that the player, who corresponds to the given sign
, captured.
board.setCaptures(sign, mutator)
sign
<Integer>
- One of-1
or1
mutator
<Function | Integer>
If mutator
is a function of the following form
(prevCaptures: <Integer>) -> <Integer>
we will update the capture count of the player who corresponds to the given sign
according to the mutator
function. If mutator
is an integer, we will directly set the capture count to mutator
instead. This function mutates the board and returns this
to enable chaining.
Board Property Functions
board.isSquare()
Equivalent to board.width === board.height
.
board.isEmpty()
Returns true
if signMap
contains 0
only, otherwise false
.
board.isValid()
Returns true
if all chains have at least one liberty, otherwise false
.
Topology Functions
board.getDistance(vertex1, vertex2)
Returns the Manhattan distance between the given vertices.
board.getNeighbors(vertex)
vertex
<Vertex>
Returns an array of vertices on the board that are exactly Manhattan distance 1
away from the given vertex
.
board.getConnectedComponent(vertex, predicate)
vertex
<Vertex>
predicate
<Function>
predicate
is a function of the following form:
(vertex: <Vertex>) -> <Boolean>
Returns a list of vertices that fulfill predicate
and connect to vertex
through a string of vertices that all fulfill predicate
.
board.getChain(vertex)
vertex
<Vertex>
Equivalent to board.getConnectedComponent(vertex, v => board.get(v) === board.get(vertex))
.
board.getRelatedChains(vertex)
vertex
<Vertex>
Returns an array of vertices of the same sign as vertex
that belong to the same enemy area as vertex
.
board.getLiberties(vertex)
vertex
<Vertex>
Returns an array of vertices that represents the liberties of the chain that vertex
belongs to.
board.hasLiberties(vertex)
vertex
<Vertex>
Equivalent to board.getLiberties(vertex).length > 0
, but faster.
Helper Functions
board.clone()
Returns a new Board
instance that is equivalent to board
, but mutations to either of them will not affect one another.
board.diff(otherBoard)
board
<Board>
Returns an array of vertices whose signs are not identical in board
and otherBoard
. If otherBoard
has different dimensions from board
, this will return null
.
board.stringifyVertex(vertex)
vertex
<Vertex>
Returns a string that represents the given vertex
. If vertex
is invalid or not on the board, an empty string will be returned.
board.parseVertex(coord)
coord
<String>
Returns a vertex that the given coord
represents. If coord
is invalid or not on the board, [-1, -1]
will be returned.
board.getHandicapPlacement(count)
count
<Integer>
Returns a list of vertices that represent the positions of black handicap stones.