Re: [Chicken-users] ffi - the right way to return a list holding integers and strings

[Zbigniew]

hostinfo egg also contains an example array0->string-vector which
takes a NULL-terminated array of char* and returns a vector of scheme
strings.  It also points you to how to construct a list instead.
Drawback is you have to be careful that you don't allocate too much
data or you'll overflow the nursery.

On 7/6/07, felix winkelmann <address@hidden> wrote:
> On 7/6/07, foobar <address@hidden> wrote:
> >
> > Great thanks. Just to be sure i've done it correctly.
> > Here is an example on how i would return a list of one string element.
> >
> > (define return-a-list-with-string-elt
> >   (foreign-primitive scheme-object ()
> >                    "char str[] = \"hallo\";"
> >                    "C_word *sstr = C_alloc(C_SIZEOF_STRING(strlen(str)));"
> >                    "C_return(C_h_list(1,C_string2(&sstr,str)));"))

> I'd perhaps do it this way:
>
> (foreign-primitive scheme-object ()
>   "char *str[] = \"hallo\";"
>   "C_word *buf = C_alloc(C_SIZEOF_STRING(strlen(str)) + C_SIZEOF_PAIR);"
>   "C_word str = C_string2(&buf, str);"
>   "C_return(C_a_i_list(&buf, 1, str));")