#!perl -T ## no critic (TidyCode)

use strict;
use warnings;
use Locale::TextDomain::OO;
use Locale::TextDomain::OO::Lexicon::Hash;

our $VERSION = 0;

# switch of perlcritic because of po-file similar writing
## no critic (InterpolationOfLiterals EmptyQuotes)
Locale::TextDomain::OO::Lexicon::Hash
    ->new(
        logger => sub {
            my ($message, $arg_ref) = @_;
            () = print "$arg_ref->{type}: $message\n";
            return;
        },
    )
    ->lexicon_ref({
        # data equal to de/LC_MESSAGES/example.po (example.mo)
        # language -----^^ ^^^^^^^^^^^ ^^^^^^^
        # category --------'           |
        # domain ----------------------'
        'de:LC_MESSAGES:example' => [
            # header similar to po file
            {
                msgid  => "",
                msgstr => ""
                    . "Project-Id-Version: \n"
                    . "POT-Creation-Date: \n"
                    . "PO-Revision-Date: \n"
                    . "Last-Translator: \n"
                    . "Language-Team: \n"
                    . "MIME-Version: 1.0\n"
                    . "Content-Type: text/plain; charset=UTF-8\n"
                    . "Content-Transfer-Encoding: 8bit\n"
                    . "Plural-Forms: nplurals=2; plural=n != 1;\n",
            },
            # en -> de translation
            {
                # __
                msgid  => "This is a text.",
                msgstr => "Das ist ein Text.",
            },
            # with named placeholder
            {
                # __x
                msgid  => "{name} is programming {language}.",
                msgstr => "{name} programmiert {language}.",
            },
            # 2 en plural forms -> 2 de plural forms
            {
                # __n
                msgid         => "Singular",
                msgid_plural  => "Plural",
                msgstr_plural => [
                    # in po file written as msgstr[0]
                    "Einzahl",
                    # in po file written as msgstr[1]
                    "Mehrzahl",
                ],
            },
            # plural translation + named placeholder
            {
                # __nx
                msgid         => "{shelves :num} shelf",
                msgid_plural  => "{shelves :num} shelves",
                msgstr_plural => [
                    "{shelves :num} Regal",
                    "{shelves :num} Regale",
                ],
            },
            # context - different meaning but the same English phrase for both
            {
                # __p
                msgctxt => "maskulin",
                msgid   => "Dear",
                msgstr  => "Sehr geehrter",
            },
            # context + named placeholder
            {
                # __px
                msgctxt => "maskulin",
                msgid   => "Dear {full name}",
                msgstr  => "Sehr geehrter {full name}",
            },
            # context + plural
            {
                # __np
                msgctxt       => "appointment",
                msgid         => "date",
                msgid_plural  => "dates",
                msgstr_plural => [
                    "Date",
                    "Dates",
                ],
            },
            # context + plural + named placeholder
            {
                # __npx
                msgctxt       => "appointment",
                msgid         => "This is {dates :num} date.",
                msgid_plural  => "This are {dates :num} dates.",
                msgstr_plural => [
                    "Das ist {dates :num} Date.",
                    "Das sind {dates :num} Dates.",
                ],
            },
        ],
    });
## use critic (InterpolationOfLiterals EmptyQuotes)

my $loc = Locale::TextDomain::OO->new(
    language => 'de',          # default is 'i-default'
    category => 'LC_MESSAGES', # default is q{}
    domain   => 'example',     # default is q{}
    plugins  => [ qw( Expand::Gettext ) ],
    logger   => sub {
        my ($message, $arg_ref) = @_;
        () = print "$arg_ref->{type}: $message\n";
        return;
    },
);

# run translations
() = print map {"$_\n"}
    $loc->__(
        'not existing text',
    ),
    $loc->__(
        'This is a text.',
    ),
    $loc->__x(
        '{name} is programming {language}.',
        name     => 'Steffen',
        language => 'Perl',
    ),
    $loc->__x(
        '{name} is programming {language}.',
        name => 'Steffen',
    ),
    $loc->__n(
        'Singular',
        'Plural',
        1,
    ),
    $loc->__n(
        'Singular',
        'Plural',
        2,
    ),
    $loc->__nx(
        '{shelves :num} shelf',
        '{shelves :num} shelves',
        1,
        shelves => 1,
    ),
    $loc->__nx(
        '{shelves :num} shelf',
        '{shelves :num} shelves',
        2,
        shelves => 2,
    ),
    $loc->__p(
        'maskulin',
        'Dear',
    ),
    $loc->__px(
        'maskulin',
        'Dear {full name}',
        'full name' => 'Steffen Winkler',
    ),
    $loc->__np(
        'appointment',
        'date',
        'dates',
        1,
    ),
    $loc->__np(
        'appointment',
        'date',
        'dates',
        2,
    ),
    $loc->__npx(
        'appointment',
        'This is {dates :num} date.',
        'This are {dates :num} dates.',
        1,
        dates => 1,
    ),
    $loc->__npx(
        'appointment',
        'This is {dates :num} date.',
        'This are {dates :num} dates.',
        2,
        dates => 2,
    );

# $Id: 11_gettext_hash.pl 487 2014-02-03 14:31:43Z steffenw $

__END__

Output:

debug: Lexicon "de:LC_MESSAGES:example" loaded from hash.
warn: Using lexicon "de:LC_MESSAGES:example". msgstr not found for msgctxt=undef, msgid="not existing text".
not existing text
Das ist ein Text.
Steffen programmiert Perl.
Steffen programmiert {language}.
Einzahl
Mehrzahl
1 Regal
2 Regale
Sehr geehrter
Sehr geehrter Steffen Winkler
Date
Dates
Das ist 1 Date.
Das sind 2 Dates.