Have you ever used a language that makes heavy use of pattern matching? Prolog, in particular, or to a lesser extent (due to increasing amounts of distraction b

Have you ever used a language that makes heavy use of pattern matching? Prolog, in particular, or to a lesser extent (due to increasing amounts of distraction by other novel features) Erlang, OCaml/SML, or Haskell. It sounds like you're essentially describing functional dispatch based on structural attributes or current characteristics, rather than a (generally fixed) object identity.