Proposal: add 'equating' function to Data.List
David Feuer
david.feuer at gmail.com
Fri Jul 18 21:19:11 UTC 2014
What I'd like for Data.List is
uncons :: [a] -> Maybe (a, [a]).
uncons [] = Nothing
uncons (a:as) = Just (a,as)
I believe Data.Text and maybe even Data.ByteString have similar functions.
The main reason, I think:
The idiom
do
x <- listToMaybe xss
...
... tail xss
...
is a bit ugly as the safety of tail xs depends implicitly on the fact that
listToMaybe guards it, and because it treats the head and tail completely
differently. Far prettier:
do
(x,xs) <- uncons xss
...
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/libraries/attachments/20140718/2daf2c92/attachment-0001.html>
More information about the Libraries
mailing list