go-chess-models, v1.8

The library that implements checking and generating of chess moves.

Adding the chessmodels.SliceBoard structure; optimization.

Change Log

• new features:
  • the chessmodels.BaseBoard structure that stores a board size;
  • the chessmodels.SliceBoard structure:
    • rename the chessmodels.Board structure to chessmodels.MapBoard;
    • add the chessmodels.SliceBoard structure;
    • add the chessmodels.SliceBoard structure to the go-chess-perft tool;
    • make the chessmodels.Board type redirect to the chessmodels.SliceBoard structure;
  • transform the Pieces() methods of the chessmodels.MapBoard and chessmodels.SliceBoard structures to an independent function;
  • the chessmodels.Size structure:
    • add the PositionIndex() method;
    • add the PositionCount() method;
    • add the IteratePositions() method;
• refactoring:
  • optimize memory allocations;
• unit testing:
  • slightly improve the tests of the chessmodels.MapBoard structure:
    • of the Piece() method;
    • of the ApplyMove() method;
  • add the benchmarks based on the chessmodels.Perft() function:
    • for the chessmodels.MapBoard structure;
    • for the chessmodels.SliceBoard structure.

Features

• representing the board:
  • as an associative array of pieces with their positions as keys;
  • as a plain array of pieces with exact correspondence array indices to piece positions;
• immutable applicating moves to the board via copying the latter;
• checkings of moves:
  • universal;
  • individual for all types of pieces;
• generating moves via filtering from all possible ones;
• perft function;
• using an abstraction of a piece;
• Forsyth–Edwards Notation:
  • parsing:
    • of a position;
    • of a move;
    • of a piece kind;
    • of a piece color;
    • of a board;
  • serialization:
    • of a position;
    • of a move;
    • of a piece kind;
    • of a piece color;
    • of a board;
• utilities:
  • utility for counting all possible moves (based on the perft function):
    • counting all possible moves:
      • parameters:
        • position;
        • color that moves first;
        • analysis deep;
    • profiling:
      • targets:
        • CPU usage;
        • memory usage;
      • storing the results to a file.

Benchmarks

The chessmodels.Perft() function using the chessmodels.MapBoard structure:

BenchmarkPerft/MapBoard/initial/1Ply-8               486       2239365 ns/op      507723 B/op      13638 allocs/op
BenchmarkPerft/MapBoard/initial/2Ply-8                38      27071904 ns/op     6253672 B/op     165159 allocs/op
BenchmarkPerft/MapBoard/initial/3Ply-8                 3     394039297 ns/op    91006645 B/op    2399815 allocs/op
BenchmarkPerft/MapBoard/kiwipete/1Ply-8              150       7844416 ns/op     1959120 B/op      47637 allocs/op
BenchmarkPerft/MapBoard/kiwipete/2Ply-8                4     311539966 ns/op    80169034 B/op    1892731 allocs/op

The chessmodels.Perft() function used the chessmodels.SliceBoard structure:

BenchmarkPerft/SliceBoard/initial/1Ply-8             810       1419572 ns/op       684016 B/op     13646 allocs/op
BenchmarkPerft/SliceBoard/initial/2Ply-8              68      17883575 ns/op      8331384 B/op    165074 allocs/op
BenchmarkPerft/SliceBoard/initial/3Ply-8               4     253594389 ns/op    121325578 B/op   2399248 allocs/op
BenchmarkPerft/SliceBoard/kiwipete/1Ply-8            220       5340912 ns/op      2583824 B/op     47672 allocs/op
BenchmarkPerft/SliceBoard/kiwipete/2Ply-8              5     208109435 ns/op    103011680 B/op   1895999 allocs/op

Repository

Link: https://github.com/thewizardplusplus/go-chess-models/tree/v1.8.0.

Content: code.

License: MIT.