Forgot to record Data.Maybe.Local util module

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fr33domlover 2016-08-10 21:23:55 +00:00
parent 941bd0ea03
commit 26624404ca

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src/Data/Maybe/Local.hs Normal file
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{- This file is part of Vervis.
-
- Written in 2016 by fr33domlover <fr33domlover@riseup.net>.
-
- Copying is an act of love. Please copy, reuse and share.
-
- The author(s) have dedicated all copyright and related and neighboring
- rights to this software to the public domain worldwide. This software is
- distributed without any warranty.
-
- You should have received a copy of the CC0 Public Domain Dedication along
- with this software. If not, see
- <http://creativecommons.org/publicdomain/zero/1.0/>.
-}
module Data.Maybe.Local
( partitionMaybePairs
)
where
import Prelude
partitionMaybePairs :: [(Maybe a, Maybe b)] -> ([a], [b], [(a, b)])
partitionMaybePairs = foldr f ([], [], [])
where
f (Nothing, Nothing) ls = ls
f (Just x, Nothing) (xs, ys, ps) = (x : xs, ys, ps)
f (Nothing, Just y) (xs, ys, ps) = (xs, y : ys, ps)
f (Just x, Just y) (xs, ys, ps) = (xs, ys, (x, y) : ps)