Control.Concurrent.Class.MonadSTM.Strict.TVar

This module corresponds to TVar in "stm" package

StrictTVar

data StrictTVar m a

type LazyTVar m = TVar m

toLazyTVar :: StrictTVar m a -> LazyTVar m a

Get the underlying TVar

Since we obviously cannot guarantee that updates to this LazyTVar will be strict, this should be used with caution.

fromLazyTVar :: LazyTVar m a -> StrictTVar m a

castStrictTVar :: LazyTVar m ~ LazyTVar n => StrictTVar m a -> StrictTVar n a

newTVar :: MonadSTM m => a -> STM m (StrictTVar m a)

newTVarIO :: MonadSTM m => a -> m (StrictTVar m a)

newTVarWithInvariant

Arguments

:: (MonadSTM m, HasCallStack)

=> (a -> Maybe String)

Invariant (expect Nothing)

-> a

-> STM m (StrictTVar m a)

newTVarWithInvariantIO

Arguments

:: (MonadSTM m, HasCallStack)

=> (a -> Maybe String)

Invariant (expect Nothing)

-> a

-> m (StrictTVar m a)

readTVar :: MonadSTM m => StrictTVar m a -> STM m a

readTVarIO :: MonadSTM m => StrictTVar m a -> m a

writeTVar :: (MonadSTM m, HasCallStack) => StrictTVar m a -> a -> STM m ()

modifyTVar :: MonadSTM m => StrictTVar m a -> (a -> a) -> STM m ()

stateTVar :: MonadSTM m => StrictTVar m s -> (s -> (a, s)) -> STM m a

swapTVar :: MonadSTM m => StrictTVar m a -> a -> STM m a

check :: MonadSTM m => Bool -> STM m ()

See check.

Low-level API

checkInvariant :: HasCallStack => Maybe String -> a -> a

Check invariant (if enabled) before continuing

checkInvariant mErr x is equal to x if mErr == Nothing, and throws an error err if mErr == Just err.

This is exported so that other code that wants to conditionally check invariants can reuse the same logic, rather than having to introduce new per-package flags.

deprecated API

updateTVar :: MonadSTM m => StrictTVar m s -> (s -> (a, s)) -> STM m a

Deprecated: Use stateTVar

newTVarM :: MonadSTM m => a -> m (StrictTVar m a)

Deprecated: Use newTVarIO

newTVarWithInvariantM

Arguments

:: (MonadSTM m, HasCallStack)

=> (a -> Maybe String)

Invariant (expect Nothing)

-> a

-> m (StrictTVar m a)

Deprecated: Use newTVarWithInvariantIO

MonadLabelSTM

labelTVar :: MonadLabelledSTM m => StrictTVar m a -> String -> STM m ()

labelTVarIO :: MonadLabelledSTM m => StrictTVar m a -> String -> m ()

MonadTraceSTM

traceTVar :: MonadTraceSTM m => proxy m -> StrictTVar m a -> (Maybe a -> a -> InspectMonad m TraceValue) -> STM m ()

traceTVarIO :: MonadTraceSTM m => StrictTVar m a -> (Maybe a -> a -> InspectMonad m TraceValue) -> m ()