The idea of this project is to build a complete chess analysis suite available to all!

Right now there is a CLI program that allows you to play through a game of chess and it will verify all moves are legal and notify you of checks.

I am working on extending it with the ability to browse and edit PGN files this way, and then to build a GUI on top of it.

Later on I want to add an analysis window as an optional add-on, which talks over UCI with a chess engine.

Later on again, I'll add a chess database search dialog and then the chess suite will be complete!

This project works well with SWI-Prolog 6.6.4.

With later versions, you might need to tell prolog to treat strings as codes. But all relevant files should already have directives for that so you might be OK anyway..

If you want to try some queries, you can load load.pl and look around in the source files. The predicates are a bit disorganized but there aren't that many files to choose from anyway.

There is also a simple CLI that can be started by main:repl (defined in main.pl). There are three basic commands:

• "move xx yy zz", i.e, execute those PGN-moves and print the resulting position as FEN
• "position xx", i.e, reset the current position to "xx"
• "abort", i.e, quit the CLI.

More to come. The CLI maintains a transcript of all commands issued. The idea is to construct a prolog unit test directly from the transcript in case of an error.

A standalone program can be built using the makefile:

make

.. which should create an executable "fen" in the project root

The CLI can be extended with the ability to edit/process PGN files. If we represent the game as a tree, the user can be allowed to edit and prune variations as well as add comments.

The CLI can be extended with options for how to represent moves and how much it should print. This can be useful if we later decide to create a GUI frontend, in which case we should simplify the output for easier parsing.

Each command should get some documentation

A GUI could communicate with the CLI easily, using e.g the CLI's stdout and stdin to issue commands. Potential technologies for use here are: Java (Swing), Javascript (e.g angular/react web UI) or Prolog.

A very useful feature is the ability to search through vast amounts of games stored in database, looking for e.g a specific position or something similar (Scid is an example of a chess database that can do this). It would be nice to extend the CLI with the ability to query Scids database files for a given position.

If you want to see the 'interpreter' in action:

?- main:repl.

Position: rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1

> move e4
e2e4
Position: rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1

> move d5 Bb5
d7d5
Bf1b5+
Position: rnbqkbnr/ppp1pppp/8/1B1p4/4P3/8/PPPP1PPP/RNBQK1NR b KQkq - 1 2
CHECK
> move d6 a3
Error! Something went wrong. 
Position: rnbqkbnr/ppp1pppp/8/1B1p4/4P3/8/PPPP1PPP/RNBQK1NR b KQkq - 1 2
CHECK
> move Qd7 a3
Qd8d7
a2a3
Position: rnb1kbnr/pppqpppp/8/1B1p4/4P3/P7/1PPP1PPP/RNBQK1NR b KQkq - 0 3