New chess library Plisco (and toy engine plisco)

[gflohr]

I have published today the library Chess::Plisco for Perl. It is available on CPAN (https://metacpan.org/dist/Chess-Plisco/ ... Plisco.pod) and on Github (https://github.com/gflohr/Chess-Plisco). It also contains a UCI-compatible toy engine "plisco" which is not meant to be a serious competitor, although it can surely be an adornment of the tail of any computer chess ratings list.

The library contains a lot of things that you need for rapidly prototyping a chess engine or other chess software in Perl. Some features are:

* bitboards for board representation
* legal and pseudo-legal move generation
* generation of captures, promotions and (most) checks
* undoing moves
* static exchange evaluation
* overridable piece values
* position signatures/fingerprints using Zobrist hashing
* integrated perft interface
* parsing and generation of Standard Algebraic Notation as well as Long Algebraic Notation of moves
* parsing and generation of FEN

The software ships with a large test suite that ensures a high test coverage. Last but not least, it runs about 30 % faster than python-chess, Python's de-facto standard chess library.

Corrections, additions, and github stars if you like it, are always welcome!

[tcusr]

i never understood why people use bitboards with dynamic languages

[emadsen]

I have published today the library Chess::Plisco for Perl. It is available on CPAN (https://metacpan.org/dist/Chess-Plisco/ ... Plisco.pod) and on Github (https://github.com/gflohr/Chess-Plisco). It also contains a UCI-compatible toy engine "plisco" which is not meant to be a serious competitor, although it can surely be an adornment of the tail of any computer chess ratings list.

Cool. Perl is underrepresented in the chess engine community. So bravo for your contribution! Does Plisco understand regular expressions? Probably has better support for them than Stockfish.

[gflohr]

Cool. Perl is underrepresented in the chess engine community. So bravo for your contribution! Does Plisco understand regular expressions? Probably has better support for them than Stockfish.

Where is a chess engine supposed to understand regular expressions? I didn't really get that.

In fact, the only place where I use regexes in the core chess code is the SAN parser. From the information that I find in the move I generate a string/regex like "B..c4" and match that against all valid moves of the position to see if I find exactly one match.

[emadsen]

Where is a chess engine supposed to understand regular expressions? I didn't really get that.

It's a joke. Hence the smiley face. Perl is known for text processing and RegEx.

[gflohr]

It's a joke. Hence the smiley face. Perl is known for text processing and RegEx.

Yes, sure. I just wasn't 100 % sure that you really meant it as a joke.

But as stated above, the project is not meant to be a serious competitor in computer chess. But just like with python-chess, it can be quite helpful tohave chess functionality available in a scripting language, because you can quickly try out new ideas, you can generate test data, write driver scripts and such stuff. I am not really a Python guy, and so I had used other Perl chess libraries for such purposes in the past. But they were all way to slow sooner or later, and so I decided to write something that is on par with python-chess. Some things just don't work, when a search to depth 3 takes you a minute already.