The Perl and Raku Conference 2023 in Toronto

Lingy brings to Perl what Clojure did for Java. Immutable data, functional programming, simple concurrency and the genius of Lisp.

In this talk, Ingy döt Net (inventor of the YAML data language) will teach you how to program in Perl using Lingy, a new hosted programming language that is a Perl implementation of Clojure (a Lisp hosted by Java and the JVM). "Hosted" means that Lingy can use Perl modules, and normal Perl code can use modules written in Lingy.

Clojure was designed to make Java programming not suck. It's a Lisp dialect that feels as dynamic as Perl, but JIT compiles to JVM bytecode, making it very performant. It's a very practical language that is both ways compatible with anything written in Java. Among other things, it supports functional programming and makes concurrent programming simple.

Lingy attempts to do the same things for Perl. It feels dynamic but it JIT compiles to bytecode. This means you can very easily write "XS speed" programs and modules that use CPAN modules in Lingy. You can also publish Lingy modules to CPAN as easily as pure Perl ones.

If writing code in Lisp isn't your style, you'll also learn about YAMLScript, a new programming language that is really just an alternate syntax transpiled to Lingy. This is not just Lingy expressions expressed in YAML. YAMLScript programs are indeed valid YAML, but in a style that looks and feels more like Perl or Python imperative ones. This means you can do real programming in YAML. Yes, you can write a YAML parser in YAML!

You'll also learn how to write Perl tests in YAML with YAMLTest. They work just like Perl .t files and can be run with prove or yath.