alemelis / Bobby.jl

A mediocre chess moves validator

Bobby.jl

Bobby is a chess move validator, i.e. given a position and a candidate move, Bobby tells you whether the move is legal or not. He can also look for check/mates and stalemates.

Features

• 64-bit magic bitboards
• perft and divide calculation
• check check
• castling
• en-passant
• promotion

Install

julia> ]add Bobby

Play

You can't really play against Bobby yet, if you want to play a proper game try Chess.jl. However, you can compute the perft from any valid position. In the case of the starting position

julia> using Bobby

julia> b = Bobby.setBoard();

julia> pt = Bobby.perft(b, 5);

julia> pt.nodes

5-element Array{Int64,1}:
      20
     400
    8902
  197281
 4865609

You can also import the position from its FEN

julia> b = Bobby.loadFen("r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - 0 0");

julia> Bobby.plainPrint(b)

   ▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄
 8 █Π ⋅ ⋅ ⋅ + ⋅ ⋅ Π █
 7 █o ⋅ o o Ψ o Δ ⋅ █
 6 █Δ ζ ⋅ ⋅ o ζ o ⋅ █
 5 █⋅ ⋅ ⋅ o ζ ⋅ ⋅ ⋅ █
 4 █⋅ o ⋅ ⋅ o ⋅ ⋅ ⋅ █
 3 █⋅ ⋅ ζ ⋅ ⋅ Ψ ⋅ o █
 2 █o o o Δ Δ o o o █
 1 █Π ⋅ ⋅ ⋅ + ⋅ ⋅ Π █
   ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
    a b c d e f g h 

julia> pt = Bobby.perft(b, 4).nodes

4-element Array{Int64,1}:
      48
    2039
   97862
 4085603

Benchmarks

julia> ]activate .

julia> using Bobby

julia> using PkgBenchmark

julia> bm = benchmarkpkg(Bobby)

julia> export_markdown("benchmark.md", bm)