On 3/10/07, Robert Dockins <[EMAIL PROTECTED]> wrote:
I'm pretty sure you can define a catamorphism for any regular algebraic data type. I'm not 100% sure what the story is for non-regular (AKA nested) datatypes.
They do exist: Initial Algebra Semantics is Enough! Patricia Johann and Neil Ghani. http://crab.rutgers.edu/~pjohann/tlca07.pdf code: http://www.cs.nott.ac.uk/~nxg/Tlca07.hs Jim _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
