Transposition table hash memory now adjustable (and not infinite), wi…

…th UCI option support

Add cutnodes and internal iterative deepening to search

Additional evaluation terms

Stop init MoveStack and PieceStack with undefs as was leading to out of bounds errors in cmtable

.gitignore

@@ -3,3 +3,4 @@ src/transposition2.jl
 deps/tbprobe.so
 deps/config.jl
 deps/build.log
+builddir/

Project.toml

@@ -1,7 +1,7 @@
 name = "Astellarn"
 uuid = "f591c62c-242e-4069-a3ea-9f76b695a940"
 authors = ["Jeremy Revell"]
-version = "0.2.1"
+version = "0.2.2"
 
 [deps]
 Crayons = "a8cc5b0e-0ffa-5ad4-8c14-923d3ee1735f"

src/Astellarn.jl

@@ -1,5 +1,5 @@
 module Astellarn
-    const ASTELLARN_VERSION = "v0.2.1"
+    const ASTELLARN_VERSION = "v0.2.2"
 
     using Crayons
     using StaticArrays

src/AstellarnEngine.jl

@@ -6,4 +6,7 @@
 using Astellarn
 
 # start the uci loop
-uci_main()
+Base.@ccallable function julia_main()::Cint
+    uci_main()
+    return 0
+end

src/bitboard.jl

@@ -456,6 +456,14 @@ A bitboard representing the central files of a board.
 const CENTERFILES = FILE_C | FILE_D | FILE_E | FILE_F
 
 
+"""
+    CENTRAL_SQUARES
+
+A bitboard representing the central 4 squares of a board.
+"""
+const CENTRAL_SQUARES = (RANK_4 | RANK_5) & (FILE_D | FILE_E)
+
+
 """
     KINGFLANK
 
@@ -465,6 +473,11 @@ const KINGFLANK = @SVector [QUEENSIDE ⊻ FILE_D, QUEENSIDE, QUEENSIDE,
       CENTERFILES, CENTERFILES, KINGSIDE, KINGSIDE, KINGSIDE ⊻ FILE_E]
 
 
+distance(sqr1::Int, sqr2::Int) = max(abs(fileof(sqr1) - fileof(sqr2)), abs(rankof(sqr1) - rankof(sqr2)))
+
+const DISTANCE_BETWEEN = [distance(sqr1, sqr2) for sqr1 in 1:64, sqr2 in 1:64]
+
+
 # Custom show for bitboard types
 function Base.show(io::IO, bb::Bitboard)
     println(io, "Bitboard:")

src/board.jl

@@ -180,7 +180,7 @@ friendly(board::Board) = @inbounds board[board.turn]
 
 Return the positions, as a `Bitboard`, of all the occupied squares on the board.
 """
-occupied(board::Board) = @inbounds board[WHITE] | board[BLACK]
+occupied(board::Board) = white(board) | black(board)
 
 
 """
@@ -225,52 +225,67 @@ function Base.show(io::IO, board::Board)
 end
 
 
+"""
+    white(board::Board)
+
+Get the location of all the white pieces on the board, as a `Bitboard`.
+"""
+white(board::Board) = @inbounds board.colors[1]
+
+
+"""
+    black(board::Board)
+
+Get the location of all the black pieces on the board, as a `Bitboard`.
+"""
+black(board::Board) = @inbounds board.colors[2]
+
 """
     pawns(board::Board)
 
 Get the location of all the pawns on the `board`, as a `Bitboard`.
 """
-pawns(board::Board) = @inbounds board[PAWN]
+pawns(board::Board) = @inbounds board.pieces[1]
 
 
 """
     knights(board::Board)
 
 Get the location of all the knights on the `board`, as a `Bitboard`.
 """
-knights(board::Board) = @inbounds board[KNIGHT]
+knights(board::Board) = @inbounds board.pieces[2]
 
 
 """
     bishops(board::Board)
 
 Get the location of all the bishops on the `board`, as a `Bitboard`.
 """
-bishops(board::Board) = @inbounds board[BISHOP]
+bishops(board::Board) = @inbounds board.pieces[3]
 
 
 """
     rooks(board::Board)
 
 Get the location of all the rooks on the `board`, as a `Bitboard`.
 """
-rooks(board::Board) = @inbounds board[ROOK]
+rooks(board::Board) = @inbounds board.pieces[4]
 
 
 """
     queens(board::Board)
 
 Get the location of all the queens on the `board`, as a `Bitboard`.
 """
-queens(board::Board) = @inbounds board[QUEEN]
+queens(board::Board) = @inbounds board.pieces[5]
 
 
 """
     kings(board::Board)
 
 Get the location of all the kings on the `board`, as a `Bitboard`.
 """
-kings(board::Board) = @inbounds board[KING]
+kings(board::Board) = @inbounds board.pieces[6]
 
 
 """
@@ -338,7 +353,14 @@ cancastlequeenside(board::Board, color::Color) = isone((board.castling >> (color
 cancastlequeenside(board::Board) = cancastlequeenside(board, board.turn)
 
 
-# is the position legal
+"""
+    has_non_pawn_material(board::Board)
+
+Check if a position has non-pawn material left.
+"""
+has_non_pawn_material(board::Board) = !isempty(knights(board)) || !isempty(bishops(board)) || !isempty(rooks(board)) || !isempty(queens(board))
+
+
 """
     islegal(board::Board)
 
@@ -413,7 +435,7 @@ end
 Detects draws by insufficient material. Returns `true` if the position is drawn.
 """
 function isdrawbymaterial(board::Board)
-    piece_count = count(board[WHITE]) + count(board[BLACK])
+    piece_count = count(white(board)) + count(black(board))
     if piece_count == 2
         return true
     elseif piece_count == 3