#!/usr/local/bin/perl
use strict;
use warnings;
sub make_random_picker {
    my ( $t, @choices );
    for my $choice ( @{ shift @_ } ) {
        push @choices, ( $choice->[0] ) x $choice->[1];
        $t += $choice->[1];
    }
    return sub { $choices[ int( rand() * $t ) ] };
}

my $pick = make_random_picker([
    [ foo  => 20 ],
    [ bar  => 10 ],
    [ baz  => 10 ],
    [ hoge => 30 ],
    [ moge => 30 ],
]);
print $pick->(), "\n" for (1..20);