Re: Guile bugs

[Marko Rauhamaa <marko@pacujo.net>]

taylanbayirli@gmail.com (Taylan Ulrich "Bayırlı/Kammer"):

> Marko Rauhamaa <marko@pacujo.net> writes:
>
>> ludo@gnu.org (Ludovic Courtès):
>>
>>> I’m very skeptical about this use case (I’d use ‘mmap’ and get a
>>> bytevector.)
>>
>> Please elaborate.
>>
>>  1. Does Guile offer mmap to Scheme code?
>
> It's pretty easy to call C functions from Scheme.

Not good enough. I would have to precompile libraries for different
target platforms (or require the target environment to have a C
compiler). Besides, the need is quite generic and shouldn't require an
extension.

>>  2. What would prevent Guile's GC from scanning the mmapped area for
>>     pointers?
>
> I don't know the details but AFAIK this is no problem with Boehm GC.

I don't understand. It can be quite time-consuming to scan gigabytes of
RAM for pointers.

>>  3. How do I efficiently encode information in a bytevector in Scheme
>>     code?
>
> What sort of data?
>
> I have a library called bytestructures that imitates the C type system
> within Scheme, to be used on bytevectors that contain data structures
> generated by C code, though the library is built upon a generic core
> with which other structures can be declared as well.  Not sure if this
> helps you:
>
> https://github.com/TaylanUB/scheme-bytestructures/

That's precisely it. It would be nice to have it as part of standard
Guile.

I wonder, though, if doing that is fast enough in Scheme code.


Marko