emit package:box

Hook a committer action to a queue, creating an emitter continuation.

Emitter wraps a producer destructor. "Every Thought emits a Dice Throw" ~ Stéphane Mallarmé

An Emitter emits values of type Maybe a. Source and producer are similar metaphors. An Emitter reaches into itself for the value to emit, where itself is an opaque thing from the pov of usage.

>>> e = Emitter (pure (Just "I'm emitted"))

>>> emit e
Just "I'm emitted"

>>> emit mempty
Nothing

Buffer an emitter.

queue a stateful emitter, supplying initial state

>>> import Control.Monad.State.Lazy

>>> toListM <$|> (evalEmitter 0 <$> takeE 4 =<< qList [0..])
[0,1,2,3]

queue a stateful emitter, supplying initial state

Glues an emitter to a committer, then resupplies the emitter.

>>> (c1,l1) <- refCommitter :: IO (Committer IO Int, IO [Int])

>>> close $ toListM <$> (forkEmit <$> (qList [1..3]) <*> pure c1)
[1,2,3]

>>> l1
[1,2,3]

An Emitter continuation.

Emit from a list IORef

>>> e <- refEmitter [1..3]

>>> toListM e
[1,2,3]