27 Jul
2007
27 Jul
'07
1:07 p.m.
Others have already pointed this out, but it is worth saying again: Maybe is not the only monadic effect which makes sense during pattern-matching. Wolfram Kahl and I have explored some of these things as part of the Pattern Matching Calculus, http://sqrl.mcmaster.ca/~kahl/PMC/ [If you want to jump to the most recent, most complete version, see http://www.cas.mcmaster.ca/~kahl/Publications/TR/Kahl-Carette-Ji-2006b/] Various other monads can be used for pattern-matching-effects. While Maybe is quite classical, List and LogicT give extremely useful alternatives. Jacques