Copyright | 2013 Gabriel Gonzalez, (C) 2015 KONISHI Yohsuke |
---|---|

License | BSD-style (see the LICENSE file in the distribution) |

Maintainer | ocean0yohsuke@gmail.com |

Stability | experimental |

Portability | --- |

Safe Haskell | Safe |

Language | Haskell2010 |

This module enables you to program in Monad-Morphic style for more **deeper** level than the usual `Control.Monad.Morph`

module expresses.
You would realize exactly what ** more deeper level** means by reading the example codes, which are attached on the page bottom.
Note: many instances for Level-4 and Level-5 haven't been written yet.

- module Control.Monad.Morph
- (|>|) :: (Monad m, MFunctor t) => (forall a. m a -> n a) -> t m b -> t n b
- (|<|) :: (Monad m, MFunctor t) => t m b -> (forall a. m a -> n a) -> t n b
- (|>>|) :: (Monad m, Monad (t2 m), MFunctor t1, MFunctor t2) => (forall a. m a -> n a) -> t1 (t2 m) b -> t1 (t2 n) b
- (|<<|) :: (Monad m, Monad (t2 m), MFunctor t1, MFunctor t2) => t1 (t2 m) b -> (forall a. m a -> n a) -> t1 (t2 n) b
- (|>>>|) :: (Monad m, Monad (t3 m), Monad (t2 (t3 m)), MFunctor t1, MFunctor t2, MFunctor t3) => (forall a. m a -> n a) -> t1 (t2 (t3 m)) b -> t1 (t2 (t3 n)) b
- (|<<<|) :: (Monad m, Monad (t3 m), Monad (t2 (t3 m)), MFunctor t1, MFunctor t2, MFunctor t3) => t1 (t2 (t3 m)) b -> (forall a. m a -> n a) -> t1 (t2 (t3 n)) b
- (|>>>>|) :: (Monad m, Monad (t4 m), Monad (t3 (t4 m)), Monad (t2 (t3 (t4 m))), MFunctor t1, MFunctor t2, MFunctor t3, MFunctor t4) => (forall a. m a -> n a) -> t1 (t2 (t3 (t4 m))) b -> t1 (t2 (t3 (t4 n))) b
- (|<<<<|) :: (Monad m, Monad (t4 m), Monad (t3 (t4 m)), Monad (t2 (t3 (t4 m))), MFunctor t1, MFunctor t2, MFunctor t3, MFunctor t4) => t1 (t2 (t3 (t4 m))) b -> (forall a. m a -> n a) -> t1 (t2 (t3 (t4 n))) b
- (|>>>>>|) :: (Monad m, Monad (t5 m), Monad (t4 (t5 m)), Monad (t3 (t4 (t5 m))), Monad (t2 (t3 (t4 (t5 m)))), MFunctor t1, MFunctor t2, MFunctor t3, MFunctor t4, MFunctor t5) => (forall a. m a -> n a) -> t1 (t2 (t3 (t4 (t5 m)))) b -> t1 (t2 (t3 (t4 (t5 n)))) b
- (|<<<<<|) :: (Monad m, Monad (t5 m), Monad (t4 (t5 m)), Monad (t3 (t4 (t5 m))), Monad (t2 (t3 (t4 (t5 m)))), MFunctor t1, MFunctor t2, MFunctor t3, MFunctor t4, MFunctor t5) => t1 (t2 (t3 (t4 (t5 m)))) b -> (forall a. m a -> n a) -> t1 (t2 (t3 (t4 (t5 n)))) b

# Documentation

module Control.Monad.Morph

# Level-1

(|>|) :: (Monad m, MFunctor t) => (forall a. m a -> n a) -> t m b -> t n b infixl 2 Source

Alias for

.`hoist`

(|<|) :: (Monad m, MFunctor t) => t m b -> (forall a. m a -> n a) -> t n b infixr 2 Source

Equivalent to (|>|) with the arguments flipped.

# Level-2

(|>>|) :: (Monad m, Monad (t2 m), MFunctor t1, MFunctor t2) => (forall a. m a -> n a) -> t1 (t2 m) b -> t1 (t2 n) b infixl 2 Source

(|<<|) :: (Monad m, Monad (t2 m), MFunctor t1, MFunctor t2) => t1 (t2 m) b -> (forall a. m a -> n a) -> t1 (t2 n) b infixr 2 Source

# Level-3

(|>>>|) :: (Monad m, Monad (t3 m), Monad (t2 (t3 m)), MFunctor t1, MFunctor t2, MFunctor t3) => (forall a. m a -> n a) -> t1 (t2 (t3 m)) b -> t1 (t2 (t3 n)) b infixl 2 Source

(|<<<|) :: (Monad m, Monad (t3 m), Monad (t2 (t3 m)), MFunctor t1, MFunctor t2, MFunctor t3) => t1 (t2 (t3 m)) b -> (forall a. m a -> n a) -> t1 (t2 (t3 n)) b infixr 2 Source

# Level-4

(|>>>>|) :: (Monad m, Monad (t4 m), Monad (t3 (t4 m)), Monad (t2 (t3 (t4 m))), MFunctor t1, MFunctor t2, MFunctor t3, MFunctor t4) => (forall a. m a -> n a) -> t1 (t2 (t3 (t4 m))) b -> t1 (t2 (t3 (t4 n))) b infixl 2 Source

(|<<<<|) :: (Monad m, Monad (t4 m), Monad (t3 (t4 m)), Monad (t2 (t3 (t4 m))), MFunctor t1, MFunctor t2, MFunctor t3, MFunctor t4) => t1 (t2 (t3 (t4 m))) b -> (forall a. m a -> n a) -> t1 (t2 (t3 (t4 n))) b infixr 2 Source

# Level-5

(|>>>>>|) :: (Monad m, Monad (t5 m), Monad (t4 (t5 m)), Monad (t3 (t4 (t5 m))), Monad (t2 (t3 (t4 (t5 m)))), MFunctor t1, MFunctor t2, MFunctor t3, MFunctor t4, MFunctor t5) => (forall a. m a -> n a) -> t1 (t2 (t3 (t4 (t5 m)))) b -> t1 (t2 (t3 (t4 (t5 n)))) b infixl 2 Source

(|<<<<<|) :: (Monad m, Monad (t5 m), Monad (t4 (t5 m)), Monad (t3 (t4 (t5 m))), Monad (t2 (t3 (t4 (t5 m)))), MFunctor t1, MFunctor t2, MFunctor t3, MFunctor t4, MFunctor t5) => t1 (t2 (t3 (t4 (t5 m)))) b -> (forall a. m a -> n a) -> t1 (t2 (t3 (t4 (t5 n)))) b infixr 2 Source

# Level-2 example

Here is a monad-morph example, a level-2 monad-morph.

import DeepControl.Monad.Morph import DeepControl.Monad.Trans.State import DeepControl.Monad.Trans.Writer -- i.e. :: StateT Int Identity () tick :: State Int () tick = modify (+1) tock :: StateT Int IO () tock = do generalize |>| tick :: (Monad m) => StateT Int m () lift $ putStrLn "Tock!" :: (MonadTrans t) => t IO () -- λ> runStateT tock 0 -- Tock! -- ((),1) -- i.e. :: StateT Int (WriterT [Int] Identity) () save :: StateT Int (Writer [Int]) () save = do n <- get lift $ tell [n] program :: StateT Int (WriterT [Int] IO) () program = replicateM_ 4 $ do lift |>| tock :: (MonadTrans t) => StateT Int (t IO) () generalize |>>| save :: (Monad m) => StateT Int (WriterT [Int] m ) () -- λ> execWriterT (runStateT program 0) -- Tock! -- Tock! -- Tock! -- Tock! -- [1,2,3,4]