Re: [Haskell-cafe] Recursion in Haskell

Chaps, is there another general pattern for mylen, head or tail? mylen [] = 0 mylen (x:xs) = 1 + mylen (xs) head [] = error "what head?" head (x:xs) = x tail [] = error "no tail" tail (x:xs)= xs This pattern matching reminds me of a module on formal spec I studied at college. What are the pre-requisites for Lambda calculus? Thanks Paul