This was a recent question on StackOverflow:
http://stackoverflow.com/questions/6270324/in-haskell-how-do-you-trim-whites...
Where I started:
If you have serious text processing needs then use the text package
from hackage.
And concluded:
A quick Criterion benchmark tells me that (for a particularly long
string of words with spaces and ~200 pre and post spaces) my trim
takes 1.6 ms, the trim using reverse takes 3.5ms, and Data.Text.strip
takes 0.0016 ms.
Cheers,
Thomas
On Tue, Sep 13, 2011 at 8:03 PM, Kazu Yamamoto
Hello Cafe,
I would like to have an efficient implementation of the chop function. As you guess, the chop function drops spaces in the tail of a list.
chop " foo bar baz " -> " foo bar baz"
A naive implementation is as follows:
chopReverse :: String -> String chopReverse = reverse . dropWhile isSpace . reverse
But this is not elegant. foldr version is as follows:
chopFoldr :: String -> String chopFoldr = foldr f [] where f c [] | isSpace c = [] | otherwise = c:[] f c cs = c:cs
But this code is slower than chopReverse in some cases.
Are there any more efficient implementations of chop? Any suggestions?
--Kazu
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