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

• type GordonGenerator
  • func NewGordonGenerator(gd *gaddag.SimpleGaddag, bag *alphabet.Bag, board *board.GameBoard, ...) *GordonGenerator
  • func (gen *GordonGenerator) Gen(col int, word alphabet.MachineWord, rack *alphabet.Rack, nodeIdx uint32)
  • func (gen *GordonGenerator) GenAll(rack *alphabet.Rack)
  • func (gen *GordonGenerator) GoOn(curCol int, L alphabet.MachineLetter, word alphabet.MachineWord, ...)
  • func (gen *GordonGenerator) Plays() []*move.Move
  • func (gen *GordonGenerator) RecordPlay(word alphabet.MachineWord, startCol int, rack *alphabet.Rack)
  • func (gen *GordonGenerator) Reset()
  • func (gen *GordonGenerator) SetBoardToGame(alph *alphabet.Alphabet, game board.VsWho)
  • func (gen *GordonGenerator) SetOppRack(r *alphabet.Rack)
  • func (gen *GordonGenerator) SetSortingParameter(s SortBy)
• type SortBy

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, bag *alphabet.Bag,
	board *board.GameBoard, strategy strategy.Strategizer) *GordonGenerator

NewGordonGenerator returns a Gordon move generator.

func (*GordonGenerator) Gen

func (gen *GordonGenerator) Gen(col int, word alphabet.MachineWord, rack *alphabet.Rack,
	nodeIdx uint32)

Gen is an implementation of the Gordon Gen function.

func (*GordonGenerator) GenAll

func (gen *GordonGenerator) GenAll(rack *alphabet.Rack)

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

func (*GordonGenerator) GoOn

func (gen *GordonGenerator) GoOn(curCol int, L alphabet.MachineLetter, word alphabet.MachineWord,
	rack *alphabet.Rack, newNodeIdx uint32, oldNodeIdx uint32)

GoOn is an implementation of the Gordon GoOn function.

func (*GordonGenerator) Plays

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

Plays returns the generator's generated plays.

func (*GordonGenerator) RecordPlay

func (gen *GordonGenerator) RecordPlay(word alphabet.MachineWord, startCol int,
	rack *alphabet.Rack)

RecordPlay records a play.

func (*GordonGenerator) Reset

func (gen *GordonGenerator) Reset()

Reset resets the generator by clearing the board and refilling the bag.

func (*GordonGenerator) SetBoardToGame

func (gen *GordonGenerator) SetBoardToGame(alph *alphabet.Alphabet, game board.VsWho)

func (*GordonGenerator) SetOppRack

func (gen *GordonGenerator) SetOppRack(r *alphabet.Rack)

SetOppRack sets the opponent's rack to the passed-in value. This is used to compute equity for plays that go out.

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.

type SortBy

type SortBy int

const (
	SortByScore SortBy = iota
	SortByEquity
)