A few minor extensions to a learning exercise on the haskellwiki. There is only a minor change to the original implementation to make it compile with GHC. And some additional modules have been added.
The engine does not support double square pawn advances or castling and no support has yet been added.
Some things have been added, amateurishly:
- Print a game state (turn, board and possible moves)
- Parse a game state (and an optional move command)
- Command line state parser / transformer
- ØMQ binding
I'm using this to learn some Haskell and to work as a chess engine for a chess server.
This is not intended to be and efficient implementation and Parsing into FEN or something might be better but this is for fun and learning.
The ØMQ server has a dependency on the ØMQ and the Haskell bindings
To compile:
make
Sample format:
$ cat sample/invalid_move.txt
White
BR BN BB BQ BK BB BN BR
BP BP BP BP BP BP BP BP
-- -- -- -- -- -- -- --
-- -- -- -- -- -- -- --
-- -- -- -- -- -- -- --
-- -- -- -- -- -- -- --
WP WP WP WP WP WP WP WP
WR WN WB WQ WK WB WN WR
It can generate moves:
cat sample/gen_moves.txt | ./bin/cli
White
BR BN BB BQ BK BB BN BR
BP BP BP BP BP BP BP BP
-- -- -- -- -- -- -- --
-- -- -- -- -- -- -- --
-- -- -- -- -- -- -- --
-- -- -- -- -- -- -- --
WP WP WP WP WP WP WP WP
WR WN WB WQ WK WB WN WR
WP a2:a3 WP b2:b3 WP c2:c3 WP d2:d3 WP e2:e3 WP f2:f3 WP g2:g3 WP h2:h3 WN b1:c3 WN b1:a3 WN g1:h3 WN g1:f3WP a2:a3 WP b2:b3 WP c2:c3 WP d2:d3 WP e2:e3 WP f2:f3 WP g2:g3 WP h2:h3 WN b1:c3 WN b1:a3 WN g1:h3 WN g1:f3
It parses a state and a move action and returns the updated state (the move list can be omitted):
cat sample/make_move.txt
White
BR BN BB BQ BK BB BN BR
BP BP BP BP BP BP BP BP
-- -- -- -- -- -- -- --
-- -- -- -- -- -- -- --
-- -- -- -- -- -- -- --
-- -- -- -- -- -- -- --
WP WP WP WP WP WP WP WP
WR WN WB WQ WK WB WN WR
WP a2:a3 WP b2:b3 WP c2:c3 WP d2:d3 WP e2:e3 WP f2:f3 WP g2:g3 WP h2:h3 WN b1:c3 WN b1:a3 WN g1:h3 WN g1:f3WP a2:a3 WP b2:b3 WP c2:c3 WP d2:d3 WP e2:e3 WP f2:f3 WP g2:g3 WP h2:h3 WN b1:c3 WN b1:a3 WN g1:h3 WN g1:f3
action: WP e2:e3
Returns updated board, the turns and the possible moves.
$ cat sample/make_move.txt | ./bin/cli
Black
BR BN BB BQ BK BB BN BR
BP BP BP BP BP BP BP BP
-- -- -- -- -- -- -- --
-- -- -- -- -- -- -- --
-- -- -- -- -- -- -- --
-- -- -- -- WP -- -- --
WP WP WP WP -- WP WP WP
WR WN WB WQ WK WB WN WR
BN b8:c6 BN b8:a6 BN g8:h6 BN g8:f6 BP a7:a6 BP b7:b6 BP c7:c6 BP d7:d6 BP e7:e6 BP f7:f6 BP g7:g6 BP h7:h6
It only accepts valid moves (moves which are in the list generated):
$ cat sample/invalid_move.txt | ./bin/cli
Invalid Move
Everything else it doesn't understand it returns a parse error, it doesn't test the validity of the game state, it will parse a board full of bishops:
$ echo "BK WZ KK" | ./bin/cli
Parse Error
The server can be started to listen for connections:
$ ./bin/server
Starting Server
Then the test client will send ./sample/make_move.txt, 10 times:
$ ./bin/client
..