27 Nov
2007
27 Nov
'07
8:16 a.m.
On Nov 27, 2007 12:57 PM, Yu-Teh Shen
i have seen the documents in http://www.haskell.org/haskellwiki/Generalised_algebraic_datatype but i can not run the following code on ghci
ex:
data Term x where K :: Term (a -> b -> a) S :: Term ((a -> b -> c) -> (a -> b) -> a -> c) Const :: a -> Term a (:@) :: Term (a -> b) -> (Term a) -> Term b infixl 6 :@
could any tell me how to run the code?
Put it in a file (eg ski.hs), and run: % ghci -fglasgow-exts ski.hs You cannot enter it directly into ghci; you can't define new data types interactively. You can also put the line {-# OPTIONS_GHC -fglasgow-exts #-} At the top, to turn on glasgow extensions whenever GHC compiles this file. Luke