Control.Lens.Mutable.Internal

Documentation

class AsLens p s ref where

Convert a reference type to a SLens.

Methods

asLens :: ref a -> SLens p s a

Instances

AsLens OpST RealWorld IORef

Defined in Control.Lens.Mutable.Internal

Methods

asLens :: IORef a -> SLens OpST RealWorld a

AsLens OpMVar RealWorld MVar

View a MVar a as a SLens 'OpST RealWorld a.

Note: when this is eventually run in IO, the action will block the thread until there is a value present, as per the semantics of takeMVar#. It will then put a value into the MVar, which will block the thread if the value is absent. GHC doesn't give atomicity guarantees for MVar so it's possible this does happen, e.g. if another producer managed to "get in there" during the intervening period between the two operations. Unfortunately GHC does not provide an atomic modifyMVar function or primop.

If you don't want to deal with this, don't use an MVar, use a TMVar.

Defined in Control.Lens.Mutable.Internal

Methods

asLens :: MVar a -> SLens OpMVar RealWorld a

AsLens OpSTM RealWorld TVar

Defined in Control.Lens.Mutable.Internal

Methods

asLens :: TVar a -> SLens OpSTM RealWorld a

AsLens OpSTM RealWorld TMVar

Defined in Control.Lens.Mutable.Internal

Methods

asLens :: TMVar a -> SLens OpSTM RealWorld a

AsLens OpST s (STRef s)

Defined in Control.Lens.Mutable.Internal

Methods

asLens :: STRef s a -> SLens OpST s a

AsLens OpST s (MutVar s)

Defined in Control.Lens.Mutable.Internal

Methods

asLens :: MutVar s a -> SLens OpST s a