movegen

Documentation

Overview

Package movegen contains all the move-generating functions. It makes heavy use of the GADDAG. Implementation notes: - Is the specification in the paper a bit buggy? Basically, if I assume an anchor is the leftmost tile of a word, the way the algorithm works, it will create words blindly. For example, if I have a word FIRE on the board, and I have the letter E on my rack, and I specify F as the anchor, it will create the word EF! (Ignoring the fact that IRE is on the board) You can see this by just stepping through the algorithm. It seems that anchors can only be on the rightmost tile of a word

Index

• func AllPlaysRecorder(gen *GordonGenerator, rack *alphabet.Rack, leftstrip, rightstrip int, ...)
• func NullPlayRecorder(gen *GordonGenerator, a *alphabet.Rack, leftstrip, rightstrip int, ...)
• func TopPlayOnlyRecorder(gen *GordonGenerator, rack *alphabet.Rack, leftstrip, rightstrip int, ...)
• type GordonGenerator
  • func NewGordonGenerator(gd *gaddag.SimpleGaddag, board *board.GameBoard, ...) *GordonGenerator
  • func (gen *GordonGenerator) GenAll(rack *alphabet.Rack, addExchange bool) []*move.Move
  • func (gen *GordonGenerator) Plays() []*move.Move
  • func (gen *GordonGenerator) SetGame(g *game.Game)
  • func (gen *GordonGenerator) SetPlayRecorder(pr PlayRecorderFunc)
  • func (gen *GordonGenerator) SetSortingParameter(s SortBy)
  • func (gen *GordonGenerator) SetStrategizer(st strategy.Strategizer)
• type MoveGenerator
• type PlayRecorderFunc
• type SortBy

Functions

func AllPlaysRecorder

func AllPlaysRecorder(gen *GordonGenerator, rack *alphabet.Rack, leftstrip, rightstrip int, t move.MoveType)

func NullPlayRecorder

func NullPlayRecorder(gen *GordonGenerator, a *alphabet.Rack, leftstrip, rightstrip int, t move.MoveType)

func TopPlayOnlyRecorder

func TopPlayOnlyRecorder(gen *GordonGenerator, rack *alphabet.Rack, leftstrip, rightstrip int, t move.MoveType)

TopPlayOnlyRecorder is a heavily optimized, ugly function to avoid allocating a lot of moves just to throw them out. It only records the very top move.

Types

type GordonGenerator

type GordonGenerator struct {
	// contains filtered or unexported fields
}

GordonGenerator is the main move generation struct. It implements Steven A. Gordon's algorithm from his paper "A faster Scrabble Move Generation Algorithm"

func NewGordonGenerator

func NewGordonGenerator(gd *gaddag.SimpleGaddag, board *board.GameBoard,
	ld *alphabet.LetterDistribution) *GordonGenerator

NewGordonGenerator returns a Gordon move generator.

func (*GordonGenerator) GenAll

func (gen *GordonGenerator) GenAll(rack *alphabet.Rack, addExchange bool) []*move.Move

GenAll generates all moves on the board. It assumes anchors have already been updated, as well as cross-sets / cross-scores.

func (*GordonGenerator) Plays

func (gen *GordonGenerator) Plays() []*move.Move

Plays returns the generator's generated plays.

func (*GordonGenerator) SetGame

func (gen *GordonGenerator) SetGame(g *game.Game)

func (*GordonGenerator) SetPlayRecorder

func (gen *GordonGenerator) SetPlayRecorder(pr PlayRecorderFunc)

func (*GordonGenerator) SetSortingParameter

func (gen *GordonGenerator) SetSortingParameter(s SortBy)

SetSortingParameter tells the play sorter to sort by score, equity, or perhaps other things. This is useful for the endgame solver, which does not care about equity.

func (*GordonGenerator) SetStrategizer

func (gen *GordonGenerator) SetStrategizer(st strategy.Strategizer)

type MoveGenerator

type MoveGenerator interface {
	GenAll(rack *alphabet.Rack, addExchange bool) []*move.Move
	SetSortingParameter(s SortBy)
	Plays() []*move.Move
	SetPlayRecorder(pf PlayRecorderFunc)
	SetStrategizer(st strategy.Strategizer)
}

MoveGenerator is a generic interface for generating moves.

type PlayRecorderFunc

type PlayRecorderFunc func(*GordonGenerator, *alphabet.Rack, int, int, move.MoveType)

type SortBy

type SortBy int

const (
	SortByScore SortBy = iota
	SortByNone
)