Re: Case expressions, matching, and "constants"

18 Jul 2003


      On Thu, Jul 17, 2003 at 12:03:19PM +0100, Bayley, Alistair wrote:
...
This is what I've turned it into to get it to work. It seems a bit clumsy;
is there a better way to write this?
...
test n =
  case True of
      _ | n == one -> "one"
        | n == two -> "two"
        | otherwise -> "three"
Or you might want to use something like this:
(depending on how much your example resembles the actual code
and the number of variables you want to match)

module Main where

one         = 1
two         = 2

test n      = maybe d id (n `lookup` m)
    where
        m   = [(one,    "one")
              ,(two,    "two")
              ]
	d   = "three"
-- 
Nobody can be exactly like me. Even I have trouble doing it.

Re: Case expressions, matching, and "constants"

Remi Turk