data-accessor-transformers-0.2.1.7: Use Accessor to access state in transformers State monad

Safe HaskellSafe
LanguageHaskell98

Data.Accessor.Monad.Trans.RWS

Contents

Description

Access helper functions in a Reader-Writer-State monad

Synopsis

accessors in the form of actions in the RWS monad

set :: (Monad m, Monoid w) => T s a -> a -> RWST r w s m () Source

get :: (Monad m, Monoid w) => T s a -> RWST r w s m a Source

modify :: (Monad m, Monoid w) => T s a -> (a -> a) -> RWST r w s m () Source

getAndModify :: (Monad m, Monoid w) => T s a -> (a -> a) -> RWST r w s m a Source

Modify a record element and return its old value.

modifyAndGet :: (Monad m, Monoid w) => T s a -> (a -> a) -> RWST r w s m a Source

Modify a record element and return its new value.

(%=) :: (Monad m, Monoid w) => T s a -> a -> RWST r w s m () infix 1 Source

Infix variant of set.

(%:) :: (Monad m, Monoid w) => T s a -> (a -> a) -> RWST r w s m () infix 1 Source

Infix variant of modify.

lift a RWS monadic accessor to an accessor of a parent record

lift :: (Monad m, Monoid w) => T s1 s0 -> RWS r w s0 a -> RWST r w s1 m a Source

liftT :: (Monad m, Monoid w) => T s1 s0 -> RWST r w s0 m a -> RWST r w s1 m a Source