cd40d90 · streamly · git.iko.soy

git.iko.soy/streamly

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Add minimal docs and to multiple functions in Internal.Data.Unfold

cd40d90adithyaov6 years ago

src/Streamly/Internal/Data/Unfold.hs+44−1

compare with master

unifiedsplit

@@ -469,6 +469,12 @@ fromListM = Unfold step inject

469 step (x:xs) = x >>= \r -> return $ Yield r xs

470 step [] = return Stop

471

472+-- | Build a stream by unfolding a /monadic/ step function starting from a seed.

473+-- The step function returns the next element in the stream and the next seed

474+-- value. When it is done it returns 'Nothing' and the stream ends.

475+--

476+-- /Internal/

477+--

472{-# INLINE unfoldrM #-}

478{-# INLINE unfoldrM #-}

473unfoldrM :: Monad m => (a -> m (Maybe (b, a))) -> Unfold m a b

479unfoldrM :: Monad m => (a -> m (Maybe (b, a))) -> Unfold m a b

474unfoldrM next = Unfold step return

480unfoldrM next = Unfold step return

@@ -486,6 +492,8 @@ unfoldrM next = Unfold step return

486

492

487-- | Generates a stream replicating the seed @n@ times.

493-- | Generates a stream replicating the seed @n@ times.

488--

494--

495+-- /Internal/

496+--

489{-# INLINE replicateM #-}

497{-# INLINE replicateM #-}

490replicateM :: Monad m => Int -> Unfold m (m a) a

498replicateM :: Monad m => Int -> Unfold m (m a) a

491replicateM n = Unfold step inject

499replicateM n = Unfold step inject

@@ -504,6 +512,8 @@ replicateM n = Unfold step inject

504

512

505-- | Generates an infinite stream repeating the seed.

513-- | Generates an infinite stream repeating the seed.

506--

514--

515+-- /Internal/

516+--

507{-# INLINE repeatM #-}

517{-# INLINE repeatM #-}

508repeatM :: Monad m => Unfold m (m a) a

518repeatM :: Monad m => Unfold m (m a) a

509repeatM = Unfold step return

519repeatM = Unfold step return

@@ -514,6 +524,8 @@ repeatM = Unfold step return

514-- | Generates an infinite stream starting with the given seed and applying the

524-- | Generates an infinite stream starting with the given seed and applying the

515-- given function repeteadly.

525-- given function repeteadly.

516--

526--

527+-- /Internal/

528+--

517{-# INLINE iterateM #-}

529{-# INLINE iterateM #-}

518iterateM :: Monad m => (a -> m a) -> Unfold m a a

530iterateM :: Monad m => (a -> m a) -> Unfold m a a

519iterateM f = Unfold step f

531iterateM f = Unfold step f

@@ -526,6 +538,8 @@ iterateM f = Unfold step f

526-- | @fromIndicesM gen@ generates an infinite stream of values using @gen@

538-- | @fromIndicesM gen@ generates an infinite stream of values using @gen@

527-- starting from the seed.

539-- starting from the seed.

528--

540--

541+-- /Internal/

542+--

529{-# INLINE_NORMAL fromIndicesM #-}

543{-# INLINE_NORMAL fromIndicesM #-}

530fromIndicesM :: Monad m => (Int -> m a) -> Unfold m Int a

544fromIndicesM :: Monad m => (Int -> m a) -> Unfold m Int a

531fromIndicesM gen = Unfold step return

545fromIndicesM gen = Unfold step return

@@ -591,6 +605,10 @@ filterM f (Unfold step1 inject1) = Unfold step inject1

591filter :: Monad m => (b -> Bool) -> Unfold m a b -> Unfold m a b

605filter :: Monad m => (b -> Bool) -> Unfold m a b -> Unfold m a b

592filter f = filterM (return . f)

606filter f = filterM (return . f)

593

607

608+-- | @drop n unf@ drops @n@ elements from the stream generated by @unf@.

609+--

610+-- /Internal/

611+--

594{-# INLINE_NORMAL drop #-}

612{-# INLINE_NORMAL drop #-}

595drop :: Monad m => Int -> Unfold m a b -> Unfold m a b

613drop :: Monad m => Int -> Unfold m a b -> Unfold m a b

596drop n (Unfold step inject) = Unfold step' inject'

614drop n (Unfold step inject) = Unfold step' inject'

@@ -618,6 +636,11 @@ drop n (Unfold step inject) = Unfold step' inject'

618 Skip s -> Skip (s, 0)

636 Skip s -> Skip (s, 0)

619 Stop -> Stop

637 Stop -> Stop

620

638

639+-- | @dropWhileM f unf@ drops elements from the stream generated by @unf@ while

640+-- the condition holds true. The condition function @f@ is /monadic/ in nature.

641+--

642+-- /Internal/

643+--

621{-# INLINE_NORMAL dropWhileM #-}

644{-# INLINE_NORMAL dropWhileM #-}

622dropWhileM :: Monad m => (b -> m Bool) -> Unfold m a b -> Unfold m a b

645dropWhileM :: Monad m => (b -> m Bool) -> Unfold m a b -> Unfold m a b

623dropWhileM f (Unfold step inject) = Unfold step' inject'

646dropWhileM f (Unfold step inject) = Unfold step' inject'

@@ -648,6 +671,10 @@ dropWhileM f (Unfold step inject) = Unfold step' inject'

648 Skip s -> Skip (Right s)

671 Skip s -> Skip (Right s)

649 Stop -> Stop

672 Stop -> Stop

650

673

674+-- | Similar to 'dropWhileM' but with a pure condition function.

675+--

676+-- /Internal/

677+--

651{-# INLINE dropWhile #-}

678{-# INLINE dropWhile #-}

652dropWhile :: Monad m => (b -> Bool) -> Unfold m a b -> Unfold m a b

679dropWhile :: Monad m => (b -> Bool) -> Unfold m a b -> Unfold m a b

653dropWhile f = dropWhileM (return . f)

680dropWhile f = dropWhileM (return . f)

@@ -677,6 +704,11 @@ enumerateFromToIntegral to =

677enumerateFromIntegral :: (Monad m, Integral a, Bounded a) => Unfold m a a

704enumerateFromIntegral :: (Monad m, Integral a, Bounded a) => Unfold m a a

678enumerateFromIntegral = enumerateFromToIntegral maxBound

705enumerateFromIntegral = enumerateFromToIntegral maxBound

679

706

707+-- | Generate an infinite stream starting from the seed with increments of the

708+-- given stride.

709+--

710+-- /Internal/

711+--

680{-# INLINE enumerateFromStepNum #-}

712{-# INLINE enumerateFromStepNum #-}

681enumerateFromStepNum :: (Monad m, Num a) => a -> Unfold m a a

713enumerateFromStepNum :: (Monad m, Num a) => a -> Unfold m a a

682enumerateFromStepNum stride = Unfold step return

714enumerateFromStepNum stride = Unfold step return

@@ -684,10 +716,16 @@ enumerateFromStepNum stride = Unfold step return

684 {-# INLINE_LATE step #-}

716 {-# INLINE_LATE step #-}

685 step !s = return $ (Yield $! s) $! (s + stride)

717 step !s = return $ (Yield $! s) $! (s + stride)

686

718

719+-- | @numFrom = enumerateFromStepNum 1@

720+--

721+-- /Internal/

722+--

687{-# INLINE_NORMAL numFrom #-}

723{-# INLINE_NORMAL numFrom #-}

688numFrom :: (Monad m, Num a) => Unfold m a a

724numFrom :: (Monad m, Num a) => Unfold m a a

689numFrom = enumerateFromStepNum 1

725numFrom = enumerateFromStepNum 1

690

726

727+-- | /Internal/

728+--

691{-# INLINE_NORMAL enumerateFromToFractional #-}

729{-# INLINE_NORMAL enumerateFromToFractional #-}

692enumerateFromToFractional :: (Monad m, Fractional a, Ord a) => a -> Unfold m a a

730enumerateFromToFractional :: (Monad m, Fractional a, Ord a) => a -> Unfold m a a

693enumerateFromToFractional to =

731enumerateFromToFractional to =

@@ -703,6 +741,8 @@ data FromSVarState t m a =

703 | FromSVarLoop (SVar t m a) [ChildEvent a]

741 | FromSVarLoop (SVar t m a) [ChildEvent a]

704 | FromSVarDone (SVar t m a)

742 | FromSVarDone (SVar t m a)

705

743

744+-- | /Internal/

745+--

706{-# INLINE_NORMAL fromSVar #-}

746{-# INLINE_NORMAL fromSVar #-}

707fromSVar :: MonadAsync m => Unfold m (SVar t m a) a

747fromSVar :: MonadAsync m => Unfold m (SVar t m a) a

708fromSVar = Unfold step (return . FromSVarInit)

748fromSVar = Unfold step (return . FromSVarInit)

@@ -782,7 +822,10 @@ fromSVar = Unfold step (return . FromSVarInit)

782-- Process events received by a fold consumer from a stream producer

822-- Process events received by a fold consumer from a stream producer

783-------------------------------------------------------------------------------

823-------------------------------------------------------------------------------

784

824

785−-- XXX Why don't we do the same thing for "FromSVarInit" that we did in "fromSVar"?

825+-- XXX Have an error for "FromSVarInit" instead of undefined. The error can

826+-- redirect the user to report the failure to the developers.

827+-- | /Internal/

828+--

786{-# INLINE_NORMAL fromProducer #-}

829{-# INLINE_NORMAL fromProducer #-}

787fromProducer :: MonadAsync m => Unfold m (SVar t m a) a

830fromProducer :: MonadAsync m => Unfold m (SVar t m a) a

788fromProducer = Unfold step (return . FromSVarRead)

831fromProducer = Unfold step (return . FromSVarRead)