Sorry, you're not my type - Jonathan Worthington
Wednesday, The Onion Room, 1145, 20 mins

Type systems are useful because they allow us to turn down bad programs either at compile time, run time or a combination of the two. In this talk I'll give a quick tour of some key aspects of typing, using simple examples to cut through the maze of jargon. I'll spend some time discussing the type system in Perl 6, which will be somewhat richer than that of Perl 5. While you can write Perl 6 without caring much about typing, just as in Perl 5, this talk will explain why you might want to think about types a bit more.


  • What the heck are types and type systems, anyway?
  • What do type systems provide?
  • Why can type systems be bad?
  • Visiting the terminology zoo: static vs. dynamic typing, strong vs. weak typing, duck typing, hybrid type systems, type inference, type checking
  • Polymorphism
    • What is it all about?
    • Subtyping (through "subclassing")
    • Parametric polymorphism
  • Refinement types
  • Wrap-up, where to look to learn more
  • Questions