GoSkrafl

A concurrent SCRABBLE(tm) engine and robot, written in Go

About

GoSkrafl is a fast, concurrent SCRABBLE(tm) engine and auto-playing robot. It is a package for the Go programming language, licensed under GNU GPLv3. It has been tested on Linux and Windows, and probably works fine on MacOS too.

Out of the box, GoSkrafl supports TWL06, SOWPODS and Icelandic SCRABBLE(tm) dictionaries and corresponding tile sets. But as it employs Unicode and UTF-8 throughout, GoSkrafl can easily be tweaked to accommodate most natural languages and dictionaries, and any tile bag configuration. (The only limitation is that there cannot be more different letters in an alphabet than there are bits in the native uint type.)

The GoSkrafl package encompasses the whole game lifecycle, board, rack and bag management, move validation, scoring, word and cross-word checks, as well as robot players.

The robot players make good use of Go's goroutines to discover valid moves concurrently, employing all available processor cores for parallel execution of multiple worker threads. This, coupled with Go's compilation to native machine code, and its efficient memory management, makes GoSkrafl quite fast. (As an order of magnitude, it runs at over 25 simulated TWL06 games per second on a quad-core Intel i7-4400 processor @ 3.4 GHz, or less than 40 milliseconds per game.)

The design and code of GoSkrafl borrow heavily from a battle-hardened SCRABBLE(tm) engine in Python by the same author.

Status

GoSkrafl is currently in Beta. Issues and pull requests are welcome.

Adding new dictionaries

To add support for a new dictionary, assemble the word list in a UTF-8 text file, with all words in lower case, one word per line. Use the DAWG builder from Netskrafl to build a .bin.dawg file. Copy it to the /GoSkrafl/dicts/ directory, then add a snippet of code at the bottom of dawg.go to wrap it in an instance of the Dawg class. Remember to add an alphabet string as well, cf. the IcelandicAlphabet and EnglishAlphabet variables. The same alphabet string must be used for the encoding in dawgbuilder.py. Post an issue if you need help.

Example

To enjoy seeing two robots slug it out at the SCRABBLE(tm) board:

package main

import (
    "fmt"
    skrafl "github.com/vthorsteinsson/GoSkrafl"
)

func main() {
    // Set up a game of SOWPODS SCRABBLE(tm)
    game := skrafl.NewSowpodsGame()
    game.SetPlayerNames("Robot A", "Robot B")
    // Create a robot that always selects
    // the highest-scoring valid move
    robot := skrafl.NewHighScoreRobot()
    // Print the initial game board and racks
    fmt.Printf("%v\n", game)
    // Generate moves until the game ends
    for {
        // Extract the game state
        state := game.State()
        // Find the highest-scoring move available
        move := robot.GenerateMove(state)
        // Apply the (implicitly validated) move to the game
        game.ApplyValid(move)
        // Print the new game state after the move
        fmt.Printf("%v\n", game)
        if game.IsOver() {
            fmt.Printf("Game over!\n")
            break
        }
    }
}

A fancier main program for exercising the GoSkrafl engine can be found here.

Original Author

Vilhjálmur Þorsteinsson, Reykjavík, Iceland.

Contact me via GitHub for queries or information regarding GoSkrafl, for instance if you would like to use GoSkrafl as a basis for your own game program, server or website but prefer not to do so under the conditions of the GNU GPL v3 license (see below).

License

GoSkrafl - a concurrent SCRABBLE(tm) engine and robot, written in Go

This set of programs is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This set of programs is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

The full text of the GNU General Public License is available here: http://www.gnu.org/licenses/gpl.html.

Trademarks

SCRABBLE is a registered trademark. This software or its author are in no way affiliated with or endorsed by the owners or licensees of the SCRABBLE trademark.

ernesth65/GoSkrafl