use CGI qw(:all);
my $op = param('operation');

TestPkg->$dispatch('Hello!') if UNIVERSAL::can('TestPkg', $dispatch);

##</code><code>##

my $input = <>;

$_->($input) for
    map /^_/ ? () : *{$TestPkg::{$_}}{CODE} || (),
    keys %TestPkg::;

##</code><code>##

my $input = <>;

my $sub;
!/^_/ && *$sub{CODE} && *$sub{CODE}->($input)
    while ($_, $sub) = each %TestPkg::;

##</code><code>##

package Foo;
use Dispatch;

sub bar {
    ...
}

sub baz {
    ...
}

package main;

my $t = Foo->create_dptable;
$t->{bar}->($quux);

##</code><code>##

my $t = {
    bar => sub {
        ...
    },
    baz => sub {
        ...
    },
};

$t->{bar}->($quux);