On 9/5/07, Ketil Malde
On Wed, 2007-09-05 at 08:19 +0100, Simon Peyton-Jones wrote: Error message from GHCi: test/error.hs:2:8: No instance for (Num String) arising from use of `+' at test/error.hs:2:8-17 Possible fix: add an instance declaration for (Num String) In the expression: x + (show s) In the definition of `f': f x s = x + (show s)
your suggestion for the error message you'd like to have seen.
ghc --newbie-errors error.hs . . . . . . Error message from GHCi: test/error.hs:2:8: You have tried to apply the operator '+' to 'x' and 'show s' 'show s' is a String. I don't know how to apply '+' to a String. May I suggest either: (1) '+' is a method of type class Num. Tell me how to apply '+' to a String by making String an instance of the class Num (2) You didn't really mean '+' In the expression: x + (show s) In the definition of `f': f x s = x + (show s) -- Dan