Comment by dklsf

Probably Compiling Pattern Matching to Good Decision Trees (by Luc Maranget) is the scheme used by OCaml (http://moscova.inria.fr/%7Emaranget/papers/ml05e-maranget.pd...).

It explains how to minimize the decisions trees you obtain from a match statement, so you gain a ton of efficiency over a naive implementation, especially for large, multi-column matches.