#! /usr/bin/perl

use strict;
use warnings;

use PPI;
use PPI::Dumper;
sub mydump { PPI::Dumper->new(shift)->print() }

my $perlcode = << "END_PERLCODE";
package My::L10N::en;

use base 'My::L10N';

our %Lexicon = (
    'Some [_1] text' =>
    'Some [_1] text',

);

1;
END_PERLCODE

my $doc = PPI::Document->new(\$perlcode);
my $lexicon = $doc->find(sub { $_[1]->content eq '%Lexicon' });
$lexicon = $lexicon->[0]; # returns an array ref, but in my case, there's only ever one.

my $newmsg = q{'The [_1] is in the [_2]'};
my $newtext = sprintf "    %s =>\n    %s,\n", $newmsg, $newmsg;
my $insert_this = PPI::Document->new(\$newtext);

# insert $newtext into %Lexicon?
my $stmt = $lexicon->statement();
my $list = $stmt->find('PPI::Structure::List')->[0];

for ($insert_this->tokens())
{
    $_->remove();
    my $rc = $list->add_element($_);
}

print $doc->serialize();