YieldT monad transformer.

This package defines a class MonadYield a for monads that can emit values values of type a while they run, and a monad transformer YieldT a which implements this class such that the emitted values can be captured in a streaming manner.

This is an amalgamation of concepts from pipes, conduit, foldl, and kan-extensions, combined into a small self-contained package.

Yield

import Control.Monad.Yield

action1 :: MonadYield Char m => m Char
action1 = do
  yield 'a'
  yield 'b'
  pure 'c'

action2 :: forall m. Monad m => m (String, Char)
action2 = runYieldT listAggregation action1
-- returns ("ab", 'c')

LICENSE | CHANGELOG.