[Haskell-cafe] [SOLVED] Writing and testing a Storable instance for a record wrapping ForeignPtrs

[Viktor Dukhovni]

On Mon, Nov 28, 2022 at 06:54:39PM +0100, Hécate wrote:

> 2. What's the use case here?
> 
> The use case is certainly my own partial worldview of how it all works. 
> That being said one interesting thing is that peek & poke allow you to 
> do IO, whereas Binary's Put and Get do not seem to allow me to do it 
> (without cheating at least). And I couldn't find any instruction that 
> said that it was okay to use unsafeDupablePerformIO (or similar) in Binary.

The use-case for Data.Binary is for converting to and from ByteStrings
(possibly lazy construction via Builders).  If you want to include
reading the data from a stream, there's at least:

    https://hackage.haskell.org/package/ghc-9.4.2/docs/GHC-Utils-Binary.html

and equivalent options.  But your answer is still at much too low a
level.  What kinds of messages are these?  What sort of communication
pattern is this serialisation in aid of?

    - Haskell to FFI helper functions?
    - Haskell process to Haskell process on the same machine?
    - Haskell Process to cache for later retrieval?
    - Interprocess, possily across languages and systems?
    - ...

What are the interoperability requirements? ...

-- 
    Viktor.