2008/1/21 Alexander Seliverstov <[EMAIL PROTECTED]>: > So, the function type "(Num a)=>Integer->a" means that return value of > this function can be cast to any particular instance of class Num. > > Ok. I have a my own class "class A a" and want to write function like > this "f:: (A a)=>Integer->a". Can I do it? > > Only if you make the function f a member of class A. Then it is the responsibility of each particular type which is an instance of A to define a way of converting an Integer into a value of that type. For example:
class A a where f :: Integer -> a ... other functions... instance A Integer where f = id instance A String where f = show and so on. -Brent
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