#!/usr/bin/env perl
use strict;
use warnings;
use Data::Dumper;
use Tk;

local $Data::Dumper::Indent = 0;
my $mw = MainWindow->new(-title => "Tk / Eval");

my $expr   = '';
my $input  = $mw->Entry(-width => 50, -textvariable => \$expr);
my $output = $mw->Listbox(-width => 50, -height => 15);

my $data = {
    mw      => $mw,
    input   => $input,
    output  => $output,
    expr    => \$expr,
};

$input->bind('<Return>', [\&evalCode, $data]);

MainLoop();


sub evalCode {
    my (undef, $data) = @_;
    my $retval = eval ${$data->{expr}};
    ${$data->{expr}} = '';

    my $dumped = Dumper $retval;
    $dumped =~ s/^\$VAR\d+ = //;

    $data->{output}->insert("end", $dumped);
    return;
}