[Haskell-beginners] HUnit - testing for failed pattern match

Edward Z. Yang ezyang at MIT.EDU
Wed Feb 23 00:35:38 CET 2011

What you describe is one of the cases when a partial function is ok
(though it's probably better to do something like:

giveMeThree x
| x == 3 = True
| otherwise = error "giveMeThree: not three"

It's frequently not possible, but if you can arrange your types so that
the invalid values are not possible, even better.)


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