- module Control.Monad
- class Sharing m where
- class Trans m a b where
- eval :: (Monad m, Trans m a b) => a -> m b
- data List m a
- nil :: Monad m => m (List m a)
- cons :: Monad m => m a -> m (List m a) -> m (List m a)
- isEmpty :: Monad m => m (List m a) -> m Bool
- first :: MonadPlus m => m (List m a) -> m a
- rest :: MonadPlus m => m (List m a) -> m (List m a)
Documentation
module Control.Monad
Classes
Interface of monads that support explicit sharing.
Interface to transform nested monadic data types. The provided
| function trans
is supposed to map the given function on every
| monadic argument. The result of trans
may be of the same type
| as the argument but can also be of a different type, e.g. to
| convert a value with nested monadic arguments to a corresponding
| value without.
Monad m => Trans m Double Double | |
Monad m => Trans m Float Float | |
Monad m => Trans m Char Char | |
Monad m => Trans m Int Int | |
Monad m => Trans m Bool Bool | |
(Monad m, Trans m a a) => Trans m [m a] [a] | An instance for lists with monadic elements that lifts all | monadic effects to the top level and yields a list with | non-monadic elements. |
(Monad m, Trans m a a) => Trans m [m a] [m a] | An instance for lists with monadic elements. |
Monad m => Trans m [Double] [Double] | |
Monad m => Trans m [Float] [Float] | |
Monad m => Trans m [Char] [Char] | |
Monad m => Trans m [Int] [Int] | |
Monad m => Trans m [Bool] [Bool] | |
(Monad m, Trans m a b) => Trans m [a] (List m b) | |
(Monad m, Trans m a b) => Trans m (List m a) [b] | |
(Monad m, Trans m a b) => Trans m (List m a) (List m b) |
We provide instances of the Trans
class for some predefined
Haskell types. For flat types the function trans
just returns its
argument which has no arguments to which the given function could
be applied.
Evaluation
eval :: (Monad m, Trans m a b) => a -> m bSource
Lifts all monadic effects in nested monadic values to the top
| level. If m
is a monad for non-determinism and the argument a
| data structure with nested non-determinism then the result
| corresponds to the normal form of the argument.
Monadic lists
Data type for lists where both the head and tail are monadic.