Re: bytevector-copy creates srfi-4 vector with greater length

[tantalum <sph@posteo.eu>]

from the explanations in the manual i interpret the definition of the 
srfi-4 compatibility to be "can work on srfi-4 vectors because the 
storage is the same, even though it regards the data as 8-bit values"
i looked at the code and it seems to work just like this for the read 
and write part of the copy. for the creation part it uses 
make-bytevector with the input type copied in a generic way - i think 
this is sound so far because it does not include any special cases for 
working with srfi-4 types.
the main problem may be that SCM_BYTEVECTOR_LENGTH returns the wrong 
length - that it does not follow 8-bit interpretation
if bytevector-copy would have a input/output type discrepancy, then the 
general bytevector/srfi-4 compatibility as i understand it would be in 
question - read supported, but not create or write.

bytevector-copy! has the same issues

On 27.10.2014 12:00, taylanbayirli@gmail.com wrote:
> Mark H Weaver <mhw@netris.org> writes:
> 
>> Thoughts?
> 
> I have no experience with SRFI-4 so don't know what would be most
> pragmatic, but reading the specification, I see s8vector, u8vector,
> s16vector, etc. are all distinct data types, though u8vector 
> corresponds
> to u8vector from SRFI-66, bytevectors from R6RS, and bytevectors from
> R7RS.  Thus I would expect those four to be the same data type, and
> distinct from the other SRFI-4 types.  Correspondingly, I'd expect the
> SRFI-4/66 u8vector and R6/7RS bytevector APIs all to work on that type
> and only that type.  Other types from SRFI-4 should have their 
> dedicated
> APIs, including a copy procedure.
> 
> That seems like the relatively obvious Right Way to me, unless I'm
> missing something.
> 
> If useful, there could be a separate API of procedures that work on 
> both
> u8vector (i.e. bytevector) and other SRFI-4 data types, but otherwise
> I'm of the opinion that any distinct data type exposed to Scheme users
> should also have its dedicated API that works on no other types.
> 
> Taylan