-#! /usr/bin/perl
-#
-# Get eco.pgn from ftp://ftp.cs.kent.ac.uk/pub/djb/pgn-extract/eco.pgn,
-# or any other opening database you might want to use as a base.
-#
-use strict;
-use warnings;
-use Chess::PGN::Parse;
-
-require 'Position.pm';
-
-package ECO;
-
-our %fen_to_opening = ();
-our @openings = ();
-
-sub init {
- {
- my $pos = Position->start_pos("white", "black");
- my $key = _key_for_pos($pos);
- push @openings, { eco => 'A00', name => 'Start position' };
- $fen_to_opening{$key} = $#openings;
- }
-
- my $pgn = Chess::PGN::Parse->new("eco.pgn")
- or die "can't open eco.pgn\n";
- while ($pgn->read_game()) {
- my $tags = $pgn->tags();
- $pgn->quick_parse_game;
- my $pos = Position->start_pos("white", "black");
- my $moves = $pgn->moves // [];
- my $eco = $pgn->eco;
- next if (!defined($eco));
- my $name = $tags->{'Opening'};
- if (exists($tags->{'Variation'}) && $tags->{'Variation'} ne '') {
- $name .= ": " . $tags->{'Variation'};
- }
- for (my $i = 0; $i < scalar @$moves; ++$i) {
- my ($from_row, $from_col, $to_row, $to_col, $promo) = $pos->parse_pretty_move($moves->[$i]);
- $pos = $pos->make_move($from_row, $from_col, $to_row, $to_col, $promo, $moves->[$i]);
- }
- my $key = _key_for_pos($pos);
- push @openings, { eco => $pgn->eco(), name => $name };
- $fen_to_opening{$key} = $#openings;
- }
-}
-
-sub persist {
- my $filename = shift;
- open my $fh, ">", $filename
- or die "openings.txt: $!";
- for my $opening (@openings) {
- print $fh $opening->{'eco'}, " ", $opening->{'name'}, "\n";
- }
- close $fh;
-}
-
-sub unpersist {
- my $filename = shift;
- open my $fh, "<", $filename
- or die "openings.txt: $!";
- while (<$fh>) {
- chomp;
- push @openings, $_;
- }
- close $fh;
-}
-
-sub get_opening_num { # May return undef.
- my $pos = shift;
- return $fen_to_opening{_key_for_pos($pos)};
-}
-
-sub _key_for_pos {
- my $pos = shift;
- my $key = $pos->fen;
- # Remove the move clocks.
- $key =~ s/ \d+ \d+$//;
- return $key;
-}
-
-1;