On Sep 14, 2011, at 5:29 AM, Kazu Yamamoto (山本和彦) wrote:
Hello,
Of course, I use ByteString or Text for real programming. But I would like to know whether or not there are any efficient methods to remove a tail part of a list.
--Kazu
In that case, I would prefer this version, since it is lazier: lazyChop :: String -> String lazyChop s = pref ++ if null s' then [] else (mid_sp ++ lazyChop s') where (pref,sp_suf) = break isSpace s (mid_sp,s') = span isSpace sp_suf By "lazier" I mean: *Main> chopReverse $ "hello world " ++ undefined "*** Exception: Prelude.undefined *Main> chopFoldr $ "hello world " ++ undefined "*** Exception: Prelude.undefined *Main> lazyChop $ "hello world " ++ undefined "hello world*** Exception: Prelude.undefined Daniel