package List; # Terrible name
use strict;
use warnings;

use Cwd qw( cwd );
require File::Spec;

use vars qw( $VERSION );
$VERSION = '0.99';

sub new {
    my( $class, $path )= @_;
    my $self= { };
    if(  defined $path  ) {
        $self->look_in( $path );
    }
    bless $self, $class;
    return $self;
}

sub look_in {
    my( $self, $path )= @_;
    $path= cwd()   unless  @_ > 1;
    $path= File::Spec->canonpath($path);
    $self->{path}= $path;
    $self->{dirs}= [$path];
    $self->{files}= [];
}

sub next {
    my( $self )= @_;

    while( 1 ) {
        if(  @{ $self->{files} }  ) {
            my $file = shift @{ $self->{files} };
            if(  -d $file  ) {
                push @{ $self->{dirs} }, $file;
            }
            return $file;
        }
        if(  ! @{ $self->{dirs} }  ) {
            return;
        }
        my $dir= shift @{ $self->{dirs} };
        if(  opendir( DIR, $dir )  ) {
            $self->{files}= [
                map {
                    File::Spec->catfile( $dir, $_ );
                } File::Spec->no_upwards( readdir(DIR) )
            ];
            closedir DIR;
        } else {
            warn "opendir failed, $dir: $!\n";
        }
    }
}

1;