At 10:05 PM -0500 12/2/03, rui yang wrote:
I want to print a function which itself have some functions as it's parameters and will return some functions as the results, and I want to print out the result, does anyone knows how to define the instance declaration of show class to this function type?
[moving to Haskell Cafe] The mechanics of such an instance definition are simple enough. Letting F be your function type, this would do it:
instance Show F where showsPrec f = ... some String ...
The hard question is what the result should be. Unlike the types already in Show (such as Bool, Int, Char, etc.), there's no canonical representation for functions (other than a complete list of argument-result pairs, which would not be very useful). Regards, --Ham -- ------------------------------------------------------------------ Hamilton Richards, PhD Department of Computer Sciences Senior Lecturer The University of Texas at Austin 512-471-9525 1 University Station C0500 Taylor Hall 5.138 Austin, Texas 78712-0233 ham@cs.utexas.edu hrichrds@swbell.net ------------------------------------------------------------------