-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Basic conditional operators with monadic variants.
--   
--   A very simple library implementing various conditional operations, as
--   well as some functions for dealing with conditions in monadic code.
--   Feel free to send ideas and suggestions for new conditional operators
--   to the maintainer.
@package cond
@version 0.0


-- | A convenient set of useful conditional operators.
module Control.Cond

-- | A simple conditional function.
if' :: Bool -> a -> a -> a

-- | <a>if'</a> with the <a>Bool</a> argument at the end (infixr 1).
(??) :: a -> a -> Bool -> a

-- | A catamorphism for the Bool type. This is analogous to foldr, maybe,
--   and either. The first argument is the false case, the second argument
--   is the true case, and the last argument is the predicate value.
bool :: a -> a -> Bool -> a

-- | Composes a predicate function and 2 functions into a single function.
--   The first function is called when the predicate yields True, the
--   second when the predicate yields False.
select :: (a -> Bool) -> (a -> b) -> (a -> b) -> (a -> b)

-- | Lisp-style conditionals. If no conditions match, then a runtime
--   exception is thrown. Here's a trivial example:
--   
--   <pre>
--   signum x = cond [(x &gt; 0     , 1 )
--                   ,(x &lt; 0     , -1)
--                   ,(otherwise , 0 )]
--   </pre>
cond :: [(Bool, a)] -> a

-- | Lisp-style conditionals generalized over <a>MonadPlus</a>. If no
--   conditions match, then the result is <a>mzero</a>. This is a safer
--   variant of <a>cond</a>.
condPlus :: MonadPlus m => [(Bool, a)] -> m a

-- | <a>if'</a> lifted to <a>Monad</a>. Unlike <tt>liftM3</tt> <a>if'</a>,
--   this is short-circuiting in the monad, such that only the predicate
--   action and one of the remaining argument actions are executed.
ifM :: Monad m => m Bool -> m a -> m a -> m a

-- | Lifted boolean or. Unlike <tt>liftM2</tt> (<a>||</a>), This function
--   is short-circuiting in the monad. Fixity is the same as <a>||</a>
--   (infixr 2).
(<||>) :: Monad m => m Bool -> m Bool -> m Bool

-- | Lifted boolean and. Unlike <tt>liftM2</tt> (<a>&amp;&amp;</a>), this
--   function is short-circuiting in the monad. Fixity is the same as
--   <a>&amp;&amp;</a> (infxr 3).
(<&&>) :: Monad m => m Bool -> m Bool -> m Bool

-- | <a>cond</a> lifted to <a>Monad</a>. If no conditions match, a runtime
--   exception is thrown.
condM :: Monad m => [(m Bool, m a)] -> m a

-- | <a>condPlus</a> lifted to <a>Monad</a>. If no conditions match, then
--   <a>mzero</a> is returned.
condPlusM :: MonadPlus m => [(m Bool, m a)] -> m a