monadplus (empty) → 1.0

raw patch · 4 files changed

+134/−0 lines, 4 filesdep +basesetup-changed

Dependencies added: base

Files

• COPYING +26/−0
• Setup.lhs +4/−0
• monadplus.cabal +30/−0
• src/Control/Monad/Plus.hs +74/−0

@@ -0,0 +1,26 @@++Copyright (c) 2013, Hans Höglund+All rights reserved.++Redistribution and use in source and binary forms, with or without+modification, are permitted provided that the following conditions are met:+    * Redistributions of source code must retain the above copyright+      notice, this list of conditions and the following disclaimer.+    * Redistributions in binary form must reproduce the above copyright+      notice, this list of conditions and the following disclaimer in the+      documentation and/or other materials provided with the distribution.+    * Neither the name of the <organization> nor the+      names of its contributors may be used to endorse or promote products+      derived from this software without specific prior written permission.++THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE+DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY+DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.+

@@ -0,0 +1,4 @@+#! /usr/bin/env runhaskell++> import Distribution.Simple+> main = defaultMain

@@ -0,0 +1,30 @@++name:               monadplus+version:            1.0+cabal-version:      >= 1.6+author:             Hans Hoglund+maintainer:         Hans Hoglund <hans@hanshoglund.se>+license:            BSD3+license-file:       COPYING+synopsis:           To be written.+category:           Music+tested-with:        GHC+build-type:         Simple++description: +    Filtering and folding over arbitrary `MonadPlus` instances.++    This package generalizes many common stream operations such as+    `filter`, `catMaybes` etc.++source-repository head+  type:             git+  location:         git://github.com/hanshoglund/monadplus.git+  +library                    +    build-depends: +        base >= 4 && < 5+    hs-source-dirs: src+    exposed-modules:+        Control.Monad.Plus+    

@@ -0,0 +1,74 @@++module Control.Monad.Plus (+        MonadPlus(..),+        msum,+        mfilter,+        mremove,+        mpartition,+        mfromMaybe,+        mcatMaybes,+        mmapMaybe,+  ) where++import Control.Monad++-- | +-- Generalizes the 'listToMaybe' function.+-- +mfromList :: MonadPlus m => [a] -> m a+mfromList = msum . map return++-- | +-- Generalizes the 'remove' function.+-- +mremove :: MonadPlus m => (a -> Bool) -> m a -> m a+mremove p = mfilter (not . p)++-- | +-- Generalizes the 'partition' function.+-- +mpartition :: MonadPlus m => (a -> Bool) -> m a -> (m a, m a)+mpartition p a = (mfilter p a, mremove p a)++-- | +-- Pass through @Just@ occurrences.+-- Generalizes the 'catMaybes' function.+-- +mcatMaybes :: MonadPlus m => m (Maybe a) -> m a+mcatMaybes = (>>= maybe mzero return)++{-+    mcatMaybes a = +    a >>= maybe mzero return+-}++-- | +-- Translate maybe to an arbitrary 'MonadPlus' type.+-- Generalizes the 'maybeToList' function.+-- +mfromMaybe :: MonadPlus m => Maybe a -> m a+mfromMaybe = maybe mzero return++-- | +-- Modify or discard a value.+-- Generalizes the 'mapMaybe' function.+-- +mmapMaybe :: MonadPlus m => (a -> Maybe b) -> m a -> m b+mmapMaybe f = mcatMaybes . liftM f++mlefts :: MonadPlus m => m (Either a b) -> m a+mlefts = mcatMaybes . liftM l+    where+        l (Left a)  = Just a+        l (Right a) = Nothing++mrights :: MonadPlus m => m (Either a b) -> m b+mrights = mcatMaybes . liftM r+    where+        r (Left a)  = Nothing+        r (Right a) = Just a++mpartitionEithers :: MonadPlus m => m (Either a b) -> (m a, m b)+mpartitionEithers a = (mlefts a, mrights a)++