use Test::More q(no_plan);

# ngram2number
#
# Convert an ngram into a number given a
# hashref containing the alphabet conversion,
# and the ngram to convert.
#
# An area for improvement would be to cache the
# $base ** ( $position++ ) results.
#
# Untested (ok, now it is), no warranty, blah blah blah
#
# Update: error in code - added reverse to correct
# Update: Multiply current digit, not add; scalar keys %alphabet
# Update: Added testing commands
#
sub ngram2number {
    my ( $alphabet, $ngram ) = @_;
    my $results  = 0;
    my $position = 0;
    my $base     = scalar( keys %$alphabet );
    for my $c ( reverse split( //, $ngram ) ) {
        $results += ( $base ** ( $position++ ) ) * $alphabet->{ $c };
    }
    $results;
}

$hex = { map { ( $_ => hex( $_ ) ) } ( '0'..'9', 'a'..'f' ) };
is( ngram2number( $hex, $_ ), hex( $_ ), "$_ in hex matches" )
    for ( '0'..'9', 'a'..'f' );
is( ngram2number( $hex, $_ ), hex( $_ ), "$_ in hex matches" )
    for ( glob '{0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f}'x2 );