b218f99 · streamly · git.iko.soy

git.iko.soy/streamly

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Fix the PeekRep/PokeRep instances for U1 constructor

b218f99Harendra Kumar4 years ago

core/src/Streamly/Internal/Data/Unboxed.hs+16−15

compare with master

unifiedsplit

@@ -43,7 +43,7 @@ module Streamly.Internal.Data.Unboxed

44import Control.Monad (void, when)

45import Data.Complex (Complex((:+)))

46−import Data.Functor ((<&>), ($>))

46+import Data.Functor ((<&>))

47import Data.Functor.Const (Const(..))

48import Data.Functor.Identity (Identity(..))

49import Data.Kind (Type)

@@ -549,7 +549,10 @@ skipByte = Peeker (Builder step)

549 step :: BoundedPtr -> IO (BoundedPtr, ())

550 step (BoundedPtr arr pos end) = do

551 let next = pos + 1

552+ when (next > end)

552− when (next > end) $ error "skipByte: reading beyond limit"

553+ $ error $ "skipByte: reading beyond limit. next = "

554+ ++ show next

555+ ++ " end = " ++ show end

553 return (BoundedPtr arr next end, ())

556 return (BoundedPtr arr next end, ())

554

557

555{-# INLINE runPeeker #-}

558{-# INLINE runPeeker #-}

@@ -634,15 +637,6 @@ instance SizeOfRep V1 where

634 {-# INLINE sizeOfRep #-}

637 {-# INLINE sizeOfRep #-}

635 sizeOfRep = error "sizeOfRep: a value of a Void type must not exist"

638 sizeOfRep = error "sizeOfRep: a value of a Void type must not exist"

636

639

637−-- Unit: constructors without arguments.

638−-- Theoretically the size can be 0, but we use 1 to simplify the implementation

639−-- of an array of unit type elements. With a non-zero size we can count the number

640−-- of elements in the array based on the size of the array. Otherwise we will

641−-- have to store a virtual length in the array, but keep the physical size of

642−-- the array as 0. Or we will have to make a special handling for zero sized

643−-- elements to make the size as 1. Or we can disallow arrays with elements

644−-- having size 0.

645−--

646-- Note that when a sum type has many unit constructors only a single byte is

640-- Note that when a sum type has many unit constructors only a single byte is

647-- required to encode the type as only the constructor tag is stored.

641-- required to encode the type as only the constructor tag is stored.

648instance SizeOfRep U1 where

642instance SizeOfRep U1 where

@@ -685,6 +679,15 @@ instance (MaxArity256 (SumArity (f :+: g)), SizeOfRepSum f, SizeOfRepSum g) =>

685 max (sizeOfRepSum (undefined :: f x))

679 max (sizeOfRepSum (undefined :: f x))

686 (sizeOfRepSum (undefined :: g x))

680 (sizeOfRepSum (undefined :: g x))

687

681

682+-- Unit: constructors without arguments.

683+-- Theoretically the size can be 0, but we use 1 to simplify the implementation

684+-- of an array of unit type elements. With a non-zero size we can count the number

685+-- of elements in the array based on the size of the array. Otherwise we will

686+-- have to store a virtual length in the array, but keep the physical size of

687+-- the array as 0. Or we will have to make a special handling for zero sized

688+-- elements to make the size as 1. Or we can disallow arrays with elements

689+-- having size 0.

690+--

688{-# INLINE genericSizeOf #-}

691{-# INLINE genericSizeOf #-}

689genericSizeOf :: forall a. (SizeOfRep (Rep a)) => Proxy a -> Int

692genericSizeOf :: forall a. (SizeOfRep (Rep a)) => Proxy a -> Int

690genericSizeOf _ =

693genericSizeOf _ =

@@ -712,9 +715,7 @@ instance PokeRep V1 where

712

715

713instance PokeRep U1 where

716instance PokeRep U1 where

714 {-# INLINE pokeRep #-}

717 {-# INLINE pokeRep #-}

715− -- XXX Can we use sizeof U1 to determine the size?

718+ pokeRep _ x = pure x

716− pokeRep _ (BoundedPtr arr pos end) =

717− return (BoundedPtr arr (pos + 1) end)

718

719

719instance (PokeRep f, PokeRep g) => PokeRep (f :*: g) where

720instance (PokeRep f, PokeRep g) => PokeRep (f :*: g) where

720 {-# INLINE pokeRep #-}

721 {-# INLINE pokeRep #-}

@@ -785,7 +786,7 @@ instance PeekRep V1 where

785

786

786instance PeekRep U1 where

787instance PeekRep U1 where

787 {-# INLINE peekRep #-}

788 {-# INLINE peekRep #-}

788− peekRep = skipByte $> U1

789+ peekRep = pure U1

789

790

790instance (PeekRep f, PeekRep g) => PeekRep (f :*: g) where

791instance (PeekRep f, PeekRep g) => PeekRep (f :*: g) where

791 {-# INLINE peekRep #-}

792 {-# INLINE peekRep #-}