#! perl -slw
use strict;
use Data::Dump qw[ pp ];
use Algorithm::Combinatorics qw[ variations ];

sub nFor(&@) {
    my $code = shift;
    die "First argument must be a code ref" unless ref( $code ) eq 'CODE';
    my @limits = @_;

    my @indices = ( 0 ) x @limits;

    for( my $i = $#limits; $i >= 0; ) {
        $i = $#limits;
        $code->( @indices ), ++$indices[ $i ]
            while $indices[ $i ] < $limits[ $i ];
        $i = $#limits;
        $indices[ $i ] = 0, ++$indices[ --$i ]
            while $i >= 0 and $indices[ $i ] == $limits[ $i ];
    }
}

my @g = (
    [ qw[ A B C ] ],
    [ qw[ 1 2 3 4 ] ],
    [ qw[ yellow blue green ] ],
    [ qw[ tiny small medium large gigantic ] ],
);

my $fSize = 2;

my @varies = variations( [ 0 .. $#g ], $fSize );

nFor {
    for my $v ( @varies ) {
        print join ' ', map{ $g[ $_ ][ $_[ $_ ] ] } @$v
    }
} map scalar @$_, @g;