Important
Sherlock (in Ocaml) is no longer under developement. Please, consider using the Rust version of Sherlock instead.
A chess library written in OCaml, oriented to creating and solving chess compositions with especial emphasis on retrograde analysis.
This library's name is inspired by the amazing book "The Chess Mysteries of Sherlock Holmes", a master piece on retrograde analysis by the great Raymond Smullyan.
After cloning the repository:
-
Install a new opam switch by running
./scripts/install_build_deps.sh. -
Compile the tool by with
dune build. -
Run the tests with
dune test.
You can run dune exec retractor/retractor.exe to start a process that
waits for queries from stdin. A query must be a command followed by a valid
FEN.
The following commands are supported:
-
retract: retracts all possible moves on the given position. This corresponds to all retractions pseudo-legal retractions that lead to a well-formed position (e.g. no pawns on the first rank, exactly one king of each color, etc). The retracted positions may be illegal. -
legal: determines the legality of the given position. Two outputs are possible:- illegal: meaning that the position is definitely illegal (unreachable from the starting position by a sequence of legal moves).
- TBD: meaning that the position is probably legal, or if it is illegal, the current logic of Sherlock was not able to determine so.