[frio]

Just for my own sanity - is "multimethod" another term for a form of pattern matching? Looking at the clojure code, it strongly reminds me of Haskell:

  encounter :: Species -> Species -> Result
  encounter (Bunny _) (Lion _) = RunAway
  encounter (Lion _) (Bunny _) = Eat

etc. Of course, pseudocode, syntax errors, whatever - but it looks to be the same idea?

edit - formatting

[thurn]

A key difference is that Haskell functions can only have one type signature, so you need to explicitly make "Bunny" and "Lion" data constructors for "Species". Multimethods operate on multiple types. You can fake multimethods in Haskell with multi-parameter type classes (with the language extensions to allow undecidable and overlapping instances).

[frio]

I see. Thanks!

[Jach]

Rich Hickey actually commented on the difference between multimethods and pattern matching here: http://sadekdrobi.com/2009/05/27/multimethod-in-clojure-shou...

(Here's a pattern matching module I know of: https://github.com/brool/clojure-misc )