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Control.Monad.Trans.Select

Copyright (c) Ross Paterson 2017
License BSD-style (see the file LICENSE)
Maintainer [email protected]
Stability experimental
Portability portable
Safe Haskell Safe
Language Haskell98

Description

Selection monad transformer, modelling search algorithms.

The Select monad

type Select r = SelectT r Identity Source

Selection monad.

select :: ((a -> r) -> a) -> Select r a Source

Constructor for computations in the selection monad.

runSelect :: Select r a -> (a -> r) -> a Source

Runs a Select computation with a function for evaluating answers to select a particular answer. (The inverse of select.)

mapSelect :: (a -> a) -> Select r a -> Select r a Source

Apply a function to transform the result of a selection computation.

The SelectT monad transformer

newtype SelectT r m a Source

Selection monad transformer.

SelectT is not a functor on the category of monads, and many operations cannot be lifted through it.

Constructors

SelectT ((a -> m r) -> m a)
Instances
MonadTrans (SelectT r)
Instance details

Defined in Control.Monad.Trans.Select

Methods

lift :: Monad m => m a -> SelectT r m a Source

Monad m => Monad (SelectT r m)
Instance details

Defined in Control.Monad.Trans.Select

Methods

(>>=) :: SelectT r m a -> (a -> SelectT r m b) -> SelectT r m b Source

(>>) :: SelectT r m a -> SelectT r m b -> SelectT r m b Source

return :: a -> SelectT r m a Source

fail :: String -> SelectT r m a Source

Functor m => Functor (SelectT r m)
Instance details

Defined in Control.Monad.Trans.Select

Methods

fmap :: (a -> b) -> SelectT r m a -> SelectT r m b Source

(<$) :: a -> SelectT r m b -> SelectT r m a Source

MonadFail m => MonadFail (SelectT r m)
Instance details

Defined in Control.Monad.Trans.Select

Methods

fail :: String -> SelectT r m a Source

(Functor m, Monad m) => Applicative (SelectT r m)
Instance details

Defined in Control.Monad.Trans.Select

Methods

pure :: a -> SelectT r m a Source

(<*>) :: SelectT r m (a -> b) -> SelectT r m a -> SelectT r m b Source

liftA2 :: (a -> b -> c) -> SelectT r m a -> SelectT r m b -> SelectT r m c Source

(*>) :: SelectT r m a -> SelectT r m b -> SelectT r m b Source

(<*) :: SelectT r m a -> SelectT r m b -> SelectT r m a Source

MonadIO m => MonadIO (SelectT r m)
Instance details

Defined in Control.Monad.Trans.Select

Methods

liftIO :: IO a -> SelectT r m a Source

(Functor m, MonadPlus m) => Alternative (SelectT r m)
Instance details

Defined in Control.Monad.Trans.Select

Methods

empty :: SelectT r m a Source

(<|>) :: SelectT r m a -> SelectT r m a -> SelectT r m a Source

some :: SelectT r m a -> SelectT r m [a] Source

many :: SelectT r m a -> SelectT r m [a] Source

MonadPlus m => MonadPlus (SelectT r m)
Instance details

Defined in Control.Monad.Trans.Select

Methods

mzero :: SelectT r m a Source

mplus :: SelectT r m a -> SelectT r m a -> SelectT r m a Source

runSelectT :: SelectT r m a -> (a -> m r) -> m a Source

Runs a SelectT computation with a function for evaluating answers to select a particular answer. (The inverse of select.)

mapSelectT :: (m a -> m a) -> SelectT r m a -> SelectT r m a Source

Apply a function to transform the result of a selection computation. This has a more restricted type than the map operations for other monad transformers, because SelectT does not define a functor in the category of monads.

Monad transformation

selectToContT :: Monad m => SelectT r m a -> ContT r m a Source

Convert a selection computation to a continuation-passing computation.

selectToCont :: Monad m => SelectT r m a -> ContT r m a Source

Deprecated: Use selectToContT instead

Deprecated name for selectToContT.

© The University of Glasgow and others
Licensed under a BSD-style license (see top of the page).
https://downloads.haskell.org/~ghc/8.6.1/docs/html/libraries/transformers-0.5.5.0/Control-Monad-Trans-Select.html