my %message_types = (
   type1 => sub { $self->sub_1(@_); },
   type2 => sub { $self->sub_2(@_); },
);

$message_types{$type}->(@args);

##</code><code>##

my %message_types = (
   type1 => 'sub_1',
   type2 => 'sub_2',
);

$method = $message_types{$type};
$self->$method(@args);

##</code><code>##

my %message_types = (
   type1 => sub { $object->sub_1(@_); },
   type2 => sub { $object->sub_2(@_); },
   type3 => 'sub_3',
   type4 => 'sub_4',
   type5 => \&bla,
   type6 => \&Foo::bar,
);

$func = $message_types{$type};
if (ref($func)) {
   # It's a function.
   $func->(@args);
} else {
   # It's a method.
   $self->$func(@args);
}