File Coverage

blib/lib/Data/Dataset/ChordProgressions.pm

Criterion	Covered	Total	%
statement	44	44	100.0
branch	3	6	50.0
condition	1	3	33.3
subroutine	10	10	100.0
pod	4	4	100.0
total	62	67	92.5

package Data::Dataset::ChordProgressions;
our $AUTHORITY = 'cpan:GENE';

# ABSTRACT: Provide access to hundreds of possible chord progressions

our $VERSION = '0.0303';

use strict;
use warnings;

use Text::CSV_XS ();
use File::ShareDir qw(dist_dir);
use Music::Scales qw(get_scale_notes);
use Exporter 'import';

our @EXPORT = qw(
    as_file
    as_list
    as_hash
    transpose
);



sub as_file {
    my $file = eval { dist_dir('Data-Dataset-ChordProgressions') . '/Chord-Progressions.csv' };

    $file = 'share/Chord-Progressions.csv'
        unless $file && -e $file;

    return $file;
}


sub as_list {
    my $file = as_file();

    my @data;

    my $csv = Text::CSV_XS->new({ binary => 1 });

    open my $fh, '<', $file
        or die "Can't read $file: $!";

    while (my $row = $csv->getline($fh)) {
        push @data, $row;
    }

    close $fh;

    return @data;
}


sub as_hash {
    my $file = as_file();

    my %data;

    my $csv = Text::CSV_XS->new({ binary => 1 });

    open my $fh, '<', $file
        or die "Can't read $file: $!";

    while (my $row = $csv->getline($fh)) {
        # Row = Genre, Key, Type, Chords, Roman
        push @{ $data{ $row->[0] }{ $row->[1] }{ $row->[2] } }, [ $row->[3], $row->[4] ];
    }

    close $fh;

    return %data;
}


sub transpose {
    my ($note, $scale, $progression) = @_;

    my %note_map;
    @note_map{ get_scale_notes('C', $scale) } = get_scale_notes($note, $scale);

    # transpose the progression chords from C
    $progression =~ s/([A-G][#b]?)/$note_map{$1}/g;

    return $progression;
}

1;

__END__