Ilia Denisov
15c7959d96
A Go library that returns every legal play ranked by score and scores or validates plays, using the Appel-Jacobson DAWG algorithm over github.com/iliadenisov/dafsa v1.1.0. - DAWG move generation (across / down / both), full tournament scoring with a per-tile breakdown; public Solver: GenerateMoves (ranked), ScorePlay, ValidatePlay. - Rulesets: English Scrabble, Russian Scrabble, Эрудит (parameterizable Ruleset). - cmd/builddict (build the DAWG from the dictionaries submodule), cmd/stress (self-play benchmark), selfplay engine; brute-force test oracle. - A GADDAG was implemented, benchmarked and removed (the DAWG was smaller and faster for a scoring solver); see RESULTS.md and ALGORITHM.md.
44 lines
1.5 KiB
Go
44 lines
1.5 KiB
Go
// Package encoding defines the compact byte conventions shared by the board, rack,
|
|
// move output and (for letters) the dictionary graph.
|
|
//
|
|
// One uniform "symbol byte" is used everywhere:
|
|
//
|
|
// bits 0..5 the alphabet letter index plus one (1..63); 0 means "empty / no tile"
|
|
// bit 6 reserved (unused)
|
|
// bit 7 Blank — the tile is a blank standing for that letter; it scores 0
|
|
//
|
|
// The +1 offset lets 0 mean an empty board square. The same byte represents a board
|
|
// cell, a placed tile and a rack tile; the graph stores raw letter indexes (without the
|
|
// +1).
|
|
package encoding
|
|
|
|
const (
|
|
// Blank flags a tile as a blank standing for its letter; a blank scores 0.
|
|
Blank byte = 0x80
|
|
|
|
// Empty is the value of an unoccupied board square.
|
|
Empty byte = 0x00
|
|
|
|
letterBits byte = 0x3f // low 6 bits: letter index + 1
|
|
)
|
|
|
|
// Cell builds the byte for a tile of the given alphabet letter index. When blank is
|
|
// true the tile is marked as a blank (it scores 0).
|
|
func Cell(letter byte, blank bool) byte {
|
|
c := (letter + 1) & letterBits
|
|
if blank {
|
|
c |= Blank
|
|
}
|
|
return c
|
|
}
|
|
|
|
// IsEmpty reports whether a board cell is unoccupied.
|
|
func IsEmpty(cell byte) bool { return cell&letterBits == 0 }
|
|
|
|
// Letter returns the alphabet letter index of a non-empty cell or tile byte. The
|
|
// result is meaningless for an empty cell.
|
|
func Letter(cell byte) byte { return (cell & letterBits) - 1 }
|
|
|
|
// IsBlank reports whether a cell or tile byte is a blank (scores 0).
|
|
func IsBlank(cell byte) bool { return cell&Blank != 0 }
|