need help on exercise

Hi, I am working on exercise 12.5 from "Haskell, The Craft of Functional Programming, second edition" by Simon Thompson. It asks to make Int an instance in the Visible class. I have tried multiple ways of doing this however I keep receiving the same error messege when I compile my program, saying that my types do not match and i have given a (Num a, Visible a) => String, when it is supposed to be an Int -> String. If anyone could help me with this issue it would be greatly appreciated. Thanks, Kelly

At 17:39 25/06/04 -0400, kasager wrote:
Hi, I am working on exercise 12.5 from "Haskell, The Craft of Functional Programming, second edition" by Simon Thompson. It asks to make Int an instance in the Visible class. I have tried multiple ways of doing this however I keep receiving the same error messege when I compile my program, saying that my types do not match and i have given a (Num a, Visible a) => String, when it is supposed to be an Int -> String. If anyone could help me with this issue it would be greatly appreciated. Thanks, Kelly
From your description, it looks as if you could have syntax problems with the class instance declaration. It would help if you posted the offending code excerpt and message. As far as I can tell, the exercise does not call for use of context declarations (... => ...). #g ------------ Graham Klyne For email: http://www.ninebynine.org/#Contact
participants (2)
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Graham Klyne
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kasager