composewell/streamly
1
1
Fork 0
mirror of https://github.com/composewell/streamly.git synced 2024-09-11 11:37:22 +03:00
Code Issues Packages Projects Releases Wiki Activity

Add cautions about Unbox type class usage

Browse Source
This commit is contained in:
Harendra Kumar 2023-01-12 08:20:47 +05:30
parent 61c4ea467e
commit 4969d04f13
1 changed files with 6 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
core/src/Streamly/Internal/Data/Unboxed.hs
View File

@ -226,8 +226,9 @@ unpin arr@(MutableByteArray marr#) =
-- deserializes the boxed type from the mutable byte array. The write operation
-- 'pokeByteIndex' serializes the boxed type to the mutable byte array.
--
-- Instances can be derived via 'Generic'. Here is an example, for deriving an
-- instance of this type class.
-- Instances can be derived via 'Generic'. Note that the data type must be
-- non-recursive. Here is an example, for deriving an instance of this type
-- class.
--
-- >>> import GHC.Generics (Generic)
-- >>> :{
@ -237,6 +238,8 @@ unpin arr@(MutableByteArray marr#) =
-- } deriving Generic
-- :}
--
-- WARNING! Generic deriving hangs for recursive data types.
--
-- >>> import Streamly.Data.Array (Unbox(..))
-- >>> instance Unbox Object
--
@ -255,7 +258,7 @@ unpin arr@(MutableByteArray marr#) =
-- :}
--
class Unbox a where
-- | Get the size.
-- | Get the size. Size cannot be zero.
sizeOf :: Proxy a -> Int
default sizeOf :: (SizeOfRep (Rep a)) => Proxy a -> Int