simple rewrite rule example

Jan Christiansen jac at
Tue Jun 22 02:32:52 EDT 2010


I'd like to learn how to use ghc rewrite rules. I simply want to  
replace a function called f by a function called g. I do not  
unterstand why the rule f->g does not fire.

Cheers, Jan

module Main where

   "f->g"    forall x. f x = g x

main :: IO ()
main = print (f 1)

{-# NOINLINE f #-}
f :: a -> Bool
f _ = False

g :: a -> Bool
g _ = True

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