On Sun, Aug 7, 2011 at 12:54 AM, Christopher Howard
One more quick question: If I hide my actual constructors in favor of a smart constructor, is it no longer possible for me to do direct pattern matching on the values? E.g., the compiler does not allow this:
analyze (Natural 5) = "It's a five!!!"
...so I have to do this:
analyze a | natural 5 = "It's a five!!!"
You can use non-standard GHC extensions: Given a function: someView :: Natural a -> a you can pattern match like so: case myNat of (someView -> 5) -> "It's a five!!!" This requires {-# LANGUAGE ViewPatterns #-} at the top of your source file to enable. Antoine
-- frigidcode.com theologia.indicium.us
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