えっと、ちょっと考えて作っただけなんで、超適当です。

・Elch.pm（Mooseがシカらしいんで、独語でシカにしてみた）

package Elch;


use Exporter;

@ISA    = (Exporter);

@EXPORT = qw(has);

my ($class, $file, $line)  = caller;

sub has {

    my $method  = shift;

    my ($arg)   = @_;

    my $routine = {};

    if (exists $arg->{'is'}) {

        my $is  = $arg->{'is'};

        if ($is eq 'ro') {

            $routine    = sub {

                die "this is readonly" if scalar @_ > 1;

                return $_[0]->{$method};

            };

        } elsif ($is eq 'rw') {

            $routine    = sub {

                return $_[0]->{$method} = $_[1];

            };

        }

    }

    *{"${class}::${method}"}   = $routine;

}

*{"${class}::new"} = sub {

    my $self    = shift;

    my (%arg)   = @_;

    my $member  = {};

    foreach my $key (keys %arg) {

        $member->{$key} = $arg{$key};

    }

    bless $member, $self;

};

1;

・Mensch.pm

package Mensch;


use Elch;

has name => {

    'is' => "ro",

};

1;

・test.pl

#!/usr/bin/perl -w


use strict;

use Mensch;

my $obj = Mensch->new(name => 'anigon');

print $obj->name, "\n";

exit;