Re: proposal: scm_string2str() and scm_symbol2str()

[stefan]

On Mon, 20 Nov 1995, Dirk Herrmann wrote:

> On Fri, 16 Nov 2001, stefan wrote:
> 
> > If noone objects I would like to put the following piece into the
> > "Decisions" section:
> > 
> >  * To have sane memory allocation interface between C and libguile
> >    put scm_c_free(), scm_c_malloc() and scm_c_realloc() into `gc.[ch]'.
> 
> What would these functions do?

/* Memory allocation functions: Used within the `SCM -> C array type' 
   conversion functions.  These should be used instead of the standard
   malloc(), free() and realloc() functions provided by any underlying
   libc implementation.  It avoids problems with applications using a
   installed Guile library (libguile) and which use a different libc 
   implementation.  */

Thus these functions are very simple wrappers for free(), malloc() and
realloc().

> >  * Convert and implement these gh_*() functionality:
> >    gh_scm2newstr() -> 
> >    char *scm_c_string2str (SCM obj, char *str, size_t *lenp)
> 
> I suggest to name this function scm_c_string2mem.  The reason is, that it
> may hold \0 characters.  And, for those conversions that work the other
> way around we have chosen to use 'mem' for char*/size_t pairs, and str for
> zero terminated character arrays.

The scm_c_string2str() function is meant to do make a copy of a string
(including \0 characters) with a trailing \0 in order to simplify the
usage of the function at C level if you don't care about the *LENP
argument. That is why I thought we should name it scm_c_string2str().  

So we need a third vote? :-)

> >    gh_scm2newsymbol() -> 
> >    char *scm_c_symbol2str (SCM obj, char *str, size_t *lenp)
> 
> Same as above:  scm_c_symbol2mem

I agree if ... same as above.

> >    gh_get_substr() -> 
> >    char *scm_c_string2substr (SCM obj, char *str, size_t start, size_t len)
> 
> Hmmm.  This should rather be named scm_c_substring2mem, shouldn't it?

Yes. Or scm_c_substring2str?

> >    gh_scm2chars() -> 
> >    char *scm_c_scm2chars (SCM obj, char *dst) 
> >    gh_scm2shorts() -> 
> >    short *scm_2_scm2shorts (SCM obj, short *dst)
> >    gh_scm2longs() -> 
> >    long *scm_c_scm2longs (SCM obj, long *dst)
> >    gh_scm2floats() -> 
> >    float *scm_c_scm2floats (SCM obj, float *dst)
> >    gh_scm2doubles() -> 
> >    double *scm_c_scm2doubles (SCM obj, double *dst)

These should convert a vector, weak vector, string, substring or uniform
vector (whatever makes sense) into a C array.

Cheers,
        address@hidden