IfElse (empty) → 0.82

raw patch · 4 files changed

+135/−0 lines, 4 filesdep +basedep +mtlsetup-changed

Dependencies added: base, mtl

Files

• Control/Monad/IfElse.hs +93/−0
• IfElse.cabal +16/−0
• LICENSE +24/−0
• Setup.hs +2/−0

@@ -0,0 +1,93 @@+{-# LANGUAGE NoMonomorphismRestriction #-}+-- | Library for control flow inside of monads with anaphoric variants on if and when and a C-like \"switch\" function.+-- +-- Information: +-- +--   [@Author@] Jeff Heard+-- +--   [@Copyright@] 2008 Jeff Heard+--   +--   [@License@] BSD+--  +--   [@Version@] 1.0+--+--   [@Status@] Alpha+module Control.Monad.IfElse where++import Control.Monad++-- A if with no else for unit returning thunks.  +--   Returns the value of the test.+-- when :: Monad m => Bool -> m () -> m Bool+-- when True action = action >> return True+-- when False _ = return False++-- | A if with no else for unit returning thunks.+--   Returns the value of the test.+whenM :: Monad m => m Bool -> m () -> m ()+whenM test action = test >>= \t -> if t then action else return ()++-- | Like a switch statement, and less cluttered than if else if+-- +-- > cond [ (t1,a1), (t2,a2), ... ]+cond :: Monad m => [(Bool, m ())] -> m ()+cond [] = return ()+cond ((True,action) : _) = action +cond ((False,_) : rest) = cond rest++-- | Like a switch statement, and less cluttered than if else if +-- +-- > condM [ (t1,a1), (t2,a2), ... ]+condM :: Monad m => [(m Bool, m ())] -> m ()+condM [] = return ()+condM ((test,action) : rest) = test >>= \t -> if t then action else condM rest++-- | Chainable anaphoric when.  Takes a maybe value.  +--  +-- if the value is Just x then execute @ action x @ , then return @ True @ .  otherwise return @ False @ .+awhen :: Monad m => Maybe a -> (a -> m ()) -> m ()+awhen Nothing _ = return ()+awhen (Just x) action = action x ++-- | Chainable anaphoric whenM.+awhenM :: Monad m => m (Maybe a) -> (a -> m ()) -> m ()+awhenM test action = test >>= \t -> case t of +                                      Just x -> action x +                                      Nothing -> return ()++-- | Anaphoric when-else chain.  Like a switch statement, but less cluttered+acond :: Monad m => [(Maybe a, a -> m ())] -> m ()+acond ((Nothing,_) : rest) = acond rest+acond ((Just x, action) : _) = action x +acond [] = return ()++-- | Anaphoric if.+aif :: Monad m => Maybe a -> (a -> m b) -> m b -> m b+aif Nothing _ elseclause = elseclause+aif (Just x) ifclause _ = ifclause x++-- | Anaphoric if where the test is in Monad m.+aifM :: Monad m => m (Maybe a) -> (a -> m b) -> m b -> m b+aifM test ifclause elseclause = test >>= \t -> aif t ifclause elseclause++-- | IO lifted @ && @+(&&^) = liftM2 (&&)++-- | IO lifted @ || @+(||^) = liftM2 (||)++-- | Conditionally do the right action based on the truth value of the left expression+(>>?) = when+infixl 1 >>?++-- | Bind the result of the last expression in an anaphoric when.  +(>>=?) = awhen+infixl 1 >>=?++-- | composition of @ >>= @ and @ >>? @+(>>=>>?) = whenM+infixl 1 >>=>>?++-- | composition of @ >>= @ and @ >>=? @+(>>=>>=?) = awhenM+infixl 1 >>=>>=?

@@ -0,0 +1,16 @@+Name:           IfElse+Version:        0.82+Cabal-Version:  >= 1.2+License:        BSD3+License-File:   LICENSE+Author:         J.R. Heard+Maintainer:     J.R. Heard+Category:       Control+Description:    Anaphoric and miscellaneous useful control-flow+Synopsis:       Anaphoric and miscellaneous useful control-flow+Build-Type:     Simple++Library+   Build-Depends: base, mtl+   Exposed-Modules: +       Control.Monad.IfElse

@@ -0,0 +1,24 @@+Copyright 2008, Jeff Heard.  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.+ +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS "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 THE COPYRIGHT HOLDERS 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 +1,2 @@+import Distribution.Simple+main = defaultMain