------------------------------------------------------------------------------
-- Example for the extension of Curry with functional patterns as described in:
--
-- Sergio Antoy, Michael Hanus:
-- Declarative Programming with Function Patterns
-- Proceedings of the International Symposium on Logic-based Program Synthesis
-- and Transformation (LOPSTR'05), Springer LNCS 3901, pp. 6-22
------------------------------------------------------------------------------

-- define an operation to compute the last element of a list
-- by a functional pattern:
last :: [a] -> a
last (_++[x]) = x

-- Example goal (showing the list elements are not evaluated):
goal1 = last [1,2,failed,3,4]


-- define a palindrome constraint using functional patterns:
pali :: [a] -> Success
pali (xs ++ reverse xs)   = success
pali (xs ++ _:reverse xs) = success

-- Example goal:
goal2 = pali "otto"


main = goal1