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Diffstat (limited to 'src/Hakyll/Core/Util')
-rw-r--r-- | src/Hakyll/Core/Util/Arrow.hs | 37 |
1 files changed, 17 insertions, 20 deletions
diff --git a/src/Hakyll/Core/Util/Arrow.hs b/src/Hakyll/Core/Util/Arrow.hs index d25bc28..1896e11 100644 --- a/src/Hakyll/Core/Util/Arrow.hs +++ b/src/Hakyll/Core/Util/Arrow.hs @@ -1,28 +1,25 @@ -- | Various arrow utility functions -- module Hakyll.Core.Util.Arrow - ( sequenceArr - , unitArr - , withUnitArr + ( constA + , sequenceA + , unitA ) where -import Prelude hiding (id) -import Control.Arrow (Arrow, (&&&), (>>>), arr, (***)) -import Control.Category (id) +import Control.Arrow (Arrow, (&&&), arr, (>>^)) -sequenceArr :: Arrow a - => [a b c] - -> a b [c] -sequenceArr = foldl reduce $ arr $ const [] - where - reduce la xa = xa &&& la >>> arr (uncurry (:)) +constA :: Arrow a + => c + -> a b c +constA = arr . const -unitArr :: Arrow a - => a b () -unitArr = arr (const ()) +sequenceA :: Arrow a + => [a b c] + -> a b [c] +sequenceA = foldl reduce $ constA [] + where + reduce la xa = xa &&& la >>^ arr (uncurry (:)) -withUnitArr :: Arrow a - => a b c - -> a () d - -> a b (c, d) -withUnitArr a1 a2 = a1 &&& unitArr >>> id *** a2 +unitA :: Arrow a + => a b () +unitA = constA () |