Re: Integer conversion proposal

[Gary Houston]

> From: Dirk Herrmann <address@hidden>
> Date: Sun, 23 Sep 2001 11:07:46 +0200 (MEST)
> 
> Which target types should we support?  Maybe we could restrict ourselves
> to a small set of target types based on the following considerations:
> 
> * IIRC, the type 'int' is considered the type that represents a machine's
>   'natural' word length.  (Correct me if I am wrong).  Thus, we should
>   provide a conversion to int and uint.
> 
> * C99 introduces a typedef that corresponds to the 'largest' supported
>   integral type.  (I don't know the name of that type any more).  We
>   should also provide a conversion to this type and the corresponding
>   unsigned one.
> 
> In principle, those two integral types would be sufficient.  All other
> conversions could be done manually by the users:

Only up to a point, e.g., socket.c deals with 128 bit integers, it
just happens that the C compiler doesn't support them directly.  It
would be nice to have a couple of more general versions of these
functions, for signed and unsigned integers:

void scm_num2sint (size_t size, SCM src, void *dest);
void scm_num2uint (size_t size, SCM src, void *dest);

which could be used like:

size_t
num2size_t (SCM src)
{
  size_t result;

  scm_num2uint (sizeof result, src, &result);
  return result;
}