Parrot Speaks Your Language

I recently finished digging through the cleanups necessary to allow Parrot languages to exist in their own separate namespaces. Before this when you tried to run code from, say, Ruby and Perl 6 in the same interpreter, they would both try to define a Hash class, for example, and step on each other's toes in a variety of ways. Now you can load as many languages as you want into the same interpreter.

I also added a hackish implementation of the :lang parameter to Perl 6's eval that loads up the appropriate compiler to use instead of the Perl 6 compiler. This means that Rakudo can now do things like this:

eval(q<VISIBLE "O HAI GUYZ">, :lang<lolcode>);
my $x = eval(q<10×5÷2>, :lang<APL>);
my $rubysub = eval(q<do |i| puts "ruby got " + i; return i + 10 end>, :lang<cardinal>);
my $schemesub = eval(q<(lambda (msg) (write "scheme got " msg "\n"))>, :lang<pheme>);
$schemesub($rubysub($x));

The output of that is:

O HAI GUYZ
25
ruby got 25
scheme got 35

The extra '25' is there because the APL spec says that any non-assignment results in a print as a side-effect.

I haven't added support for this to any of the other Parrot languages yet because I don't know what the API should look like for any other language.

I haven't added support for loading foreign libraries to Perl 6 yet because there are a couple of awkward semantic issues to work out, and I haven't added support for loading foreign libraries to any other language yet because I don't know what the API should look like.

This is where you come in, my opinionated Internet friends. If you have suggestions for the API for evaluating foreign code or loading foreign libraries in any of Ruby, Python, LOLCODE, PHP, or any other Parrot language, please speak up here or on the social news site of your choice.

Thanks go to my employer for sponsoring my work on Parrot. Most of what I've done wouldn't be possible without their support.