Hi,

Sorry for being late to reply. I have missed your mail.

In message "Re: Using "sort!" in a C extension (1.9 problem)"
on Sun, 30 Dec 2007 02:49:47 +0900, Andre Nathan <andre@digirati.com.br> writes:

|In ruby 1.8, I could use Array#sort! in a C extension like this:
|
|static VALUE
|call_sort_bang(VALUE ary)
|{
| return rb_funcall(ary, rb_intern("sort!"), 0);
|}
|
|static VALUE
|sort_i(VALUE ary)
|{
| long v1 = FIX2LONG(RARRAY_PTR(ary)[0]);
| long v2 = FIX2LONG(RARRAY_PTR(ary)[1]);
| return LONG2FIX(v1 - v2);
|}
|
|static VALUE
|foo(void)
|{
| VALUE ary = rb_ary_new();
| rb_ary_push(ary, INT2FIX(1));
| rb_ary_push(ary, INT2FIX(0));
| rb_ary_push(ary, INT2FIX(2));
| rb_iterate(call_sort_bang, ary, sort_i, 0);
| rb_funcall(rb_mKernel, rb_intern("p"), 1, ary);
| return a;
|}
|
|This would print "[0, 1, 2]" as expected. However, it doesn't work in
|ruby1.9 compiled from svn (checked out today). The problem seems to be
|that only one of the array elements is being passed to sort_i(), instead
|of a pair of elements as it's done in 1.8.
|
|What is the correct way to do this in 1.9?

In general, if you want to get multiple values from yield, you have to
use arguments added in 1.9:

static VALUE
sort_i(VALUE a1, VALUE a2, int argc, VALUE *argv)
{
long v1 = FIX2LONG(RARRAY_PTR(argv[0]));
long v2 = FIX2LONG(RARRAY_PTR(argv[1]));
return LONG2FIX(v1 - v2);
}

You may need to check argc if they are variable.

matz.

On Tue, 2008-01-08 at 09:34 +0900, Yukihiro Matsumoto wrote:
> In general, if you want to get multiple values from yield, you have to
> use arguments added in 1.9:
>
> static VALUE
> sort_i(VALUE a1, VALUE a2, int argc, VALUE *argv)
> {
> long v1 = FIX2LONG(RARRAY_PTR(argv[0]));
> long v2 = FIX2LONG(RARRAY_PTR(argv[1]));
> return LONG2FIX(v1 - v2);
> }
>
> You may need to check argc if they are variable.

Thanks Matz, Kubo ed me sorting this out.

Is there any situation where a1 will be different from argv[0] other
than the case Guy mentioned (argc == 0, and this argv[0] doesn't exist)?

Best,
Andre