7 Jul
2004
7 Jul
'04
12:24 p.m.
On Wed, 7 Jul 2004, Graham Klyne wrote:
[[ sss :: [ShowS] sss = map (++) ["abc","def","ghi","jkl"]
ssr = foldr (.) id sss ssl = foldl (.) id sss
sr = ssr "" sl = ssl ""
-- sl == sr == "abcdefghijkl" -- is there any efficiency difference? ]]
Conventional wisdom suggests that foldr is better, but I'm not sure if it really matters in this case.
foldl performs worse, e.g. for infinite lists it will need infinite time :-)