ML pattern match compilation and partial evaluation

We derive a compiler for ML style pattern matches It is conceptu ally simple and produces reasonably good compiled matches The derivation is inspired by the instrumentation and partial evaluation of na ve string match ers Following that paradigm we rst present a general and na ve ML pattern matcher instrument it to collect and exploit extra information and show that partial evaluation of the instrumented general matcher with respect to a given match produces an e cient specialized matcher We then discard the partial evaluator and show that a match compiler can be obtained just by slightly modifying the instrumented general matcher The resulting match compiler is interesting in its own right and naturally detects inexhaustive matches and redundant match rules