gistfile1.perl

my $root = '.';
my @indexes = qw(index.html);
use strict;
use warnings;
use Plack::App::File;
use Plack::App::Cascade;

sub directory_indexes {
    my ($root, @indexes) = @_;
    my $file = Plack::App::File->new(root => $root)->to_app;

    my $serve_index = sub {
        my ($index) = @_;
        return sub {
            my $env = shift;
            my $path = $env->{PATH_INFO};
            local $env->{PATH_INFO} = "$path/$index";
            return $file->($env);
        };
    };

    my $cascade = Plack::App::Cascade->new;
    for my $index (@indexes) {
        $cascade->add($serve_index->($index));
    }
    $cascade->add($file);
    return $cascade->to_app;
}

directory_indexes($root, @indexes);