26 lines
574 B
Haskell
26 lines
574 B
Haskell
{- monadic conditional operators
|
|
-
|
|
- Copyright 2011 Joey Hess <joey@kitenet.net>
|
|
-
|
|
- Licensed under the GNU GPL version 3 or higher.
|
|
-}
|
|
|
|
module Utility.Conditional where
|
|
|
|
import Control.Monad (when, unless)
|
|
|
|
whenM :: Monad m => m Bool -> m () -> m ()
|
|
whenM c a = c >>= flip when a
|
|
|
|
unlessM :: Monad m => m Bool -> m () -> m ()
|
|
unlessM c a = c >>= flip unless a
|
|
|
|
(>>?) :: Monad m => m Bool -> m () -> m ()
|
|
(>>?) = whenM
|
|
|
|
(>>!) :: Monad m => m Bool -> m () -> m ()
|
|
(>>!) = unlessM
|
|
|
|
-- low fixity allows eg, foo bar >>! error $ "failed " ++ meep
|
|
infixr 0 >>?
|
|
infixr 0 >>!
|