On 3/13/07, Kirsten Chevalier
I noticed that compiling with -O -frules-off causes the test program here to correctly print out "x". So, I was looking at the "take" rule in GHC/List.lhs. Doesn't this rule change the strictness of take?
"take" [~1] forall n xs . take n xs = case n of I# n# -> build (\c nil -> foldr (takeFB c nil) (takeConst nil) xs n#)
I may be talking to myself here, but what I mean is:
take 1 (1:undefined) [1] build (\ c nil -> foldr (takeFB c nil) (takeConst nil) (1:undefined) 1#) [1*** Exception: Prelude.undefined
(where takeFB and takeConst are defined as they are in GHC/List.lhs) So that rule doesn't seem to be quite right. Cheers, Kirsten -- Kirsten Chevalier* chevalier@alum.wellesley.edu *Often in error, never in doubt "80% of success is showing up."--Woody Allen