This should be pretty easy to do. Put each parser in a separate package with a common interface. Then in your front-end class, do:

  if ($type eq 'foo') {
     $parser = "Parser::Foo";
  } elsif ($type eq 'bar') {
     $parser = "Parser::Bar";
  } else {
     die "What the heck is $type?";
  }

  eval "use $parser" or die "Can't load $parser: $@";
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Then you make calls to your parser via the package name:

  $parser->do_that_thing($with_this);
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-sam