{-# OPTIONS_HADDOCK hide               #-}
{-# LANGUAGE CPP                       #-}
{-# LANGUAGE ExistentialQuantification #-}
{-# LANGUAGE FlexibleContexts          #-}

-- |
-- Module      : Streamly.Internal.Data.Unfold.Types
-- Copyright   : (c) 2019 Composewell Technologies
-- License     : BSD3
-- Maintainer  : streamly@composewell.com
-- Stability   : experimental
-- Portability : GHC

module Streamly.Internal.Data.Unfold.Types
    ( Unfold (..)
    )
where

import Streamly.Internal.Data.Stream.StreamD.Type (Step(..))

------------------------------------------------------------------------------
-- Monadic Unfolds
------------------------------------------------------------------------------

-- | An @Unfold m a b@ is a generator of a stream of values of type @b@ from a
-- seed of type 'a' in 'Monad' @m@.
--
-- @since 0.7.0

data Unfold m a b =
    -- | @Unfold step inject@
    forall s. Unfold (s -> m (Step s b)) (a -> m s)
