On Aug 17, 2007, at 9:11 , rodrigo.bonifacio wrote:
envKey :: EnvItem (Key, a) -> String
envKey EnvItem (key, value) = key
envValue :: EnvValue(Key, a) -> a
envValue EnvItem (key, value) = value
But this is resulting in the error: [Constructor "EnvItem" must
have exactly 1 argument in pattern]
You need to parenthesize the constructor.
envValue (EnvItem (_,value)) = value
(The _ indicates that you're not using that item, rather than giving
it a name that won't be used.)
Why do you need to do this? Because you can pass functions around,
and a constructor is a function. But your type says you don't want a
bare function there, so the compiler complains.
--
brandon s. allbery [solaris,freebsd,perl,pugs,haskell] [EMAIL PROTECTED]
system administrator [openafs,heimdal,too many hats] [EMAIL PROTECTED]
electrical and computer engineering, carnegie mellon university KF8NH
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