NQP - Not Quite Perl

Parrot is more than just PIR and PASM. I’m not talking about the ability to use languages like Raku written for the Parrot virtual machine. I am also not talking about the ability to write your own language. Both of those are quite nifty, of course. It is fair to say that those two items are probably why you are experimenting with Parrot in the first place. However, the Parrot distribution also ships with an extra language: NQP.

NQP—Not Quite Perl—is an implementation of a small subset of Perl 6 that can be used as a higher level Parrot language than PIR. It is especially useful in defining the grammars for your Parrot languages.

Getting NQP

NQP ships with Parrot!

Example

Let’s just do a brutally fast NQP example.

    #!/usr/local/bin/parrot-nqp

my $name := get_input("What is your name?");
say("Hello $name");

my $valid_input := 0;

while ($valid_input == 0) {
	my $in_good_mood := get_input("Are you in a good mood?[y/n]");
	if ($in_good_mood eq "y") {
		say("Glad to hear it! Must be all the Parrot hacking.");
		$valid_input := 1;
	} elsif ($in_good_mood eq "n") {
		say("Oh, that's too bad. Try hacking on Parrot.");
		$valid_input := 1;
	} else {
		say("Sorry, I'm not too bright. Please answer 'y' or 'n'.");
	}
}

sub get_input($prompt) {
	print("$prompt ");
	my $name := Q:PIR{
		.local pmc stdin
		stdin = getstdin
		%r = stdin.'readline_interactive'()
	};

	return $name
}
  

    $ parrot-nqp hello.nqp
What is your name? Brian
Hello Brian
Are you in a good mood?[y/n] waffles
Sorry, I'm not too bright. Please answer 'y' or 'n'.
Are you in a good mood?[y/n] y
Glad to hear it! Must be all the Parrot hacking.