From: Emil Ong <onge@...>
Date: 2001-07-04T06:18:38+09:00
Subject: [ruby-talk:17197] Re: Iterators in C

This worked great!

Thanks again,
Emil

On Wed, 4 Jul 2001, ts wrote:

> >>>>> "E" == Emil Ong <onge@mcs.anl.gov> writes:
> 
> E> an array.  I looked at rb_iterate() and its description in the pickaxe
> E> book, but I don't understand how to use it except with rb_each().
> 
>  A stupid example :
> 
> pigeon% cat tt.c
> #include <ruby.h>
> 
> static VALUE
> tt_each(tmp)
>     VALUE tmp;
> {
>     rb_funcall(tmp, rb_intern("map!"), 0, 0);
> }
> 
> static VALUE
> tt_yield(obj)
>     VALUE obj;
> {
>     int i = NUM2INT(obj);
>     rb_warn("received %d", i);
>     return (i <= 2)?Qtrue:Qfalse;
> }
> 
> static VALUE
> tt_map_bang(obj)
>     VALUE obj;
> {
>     return rb_iterate(tt_each, obj, tt_yield, 0);
> }
> 
> void Init_tt()
> {
>     rb_define_method(rb_cArray, "tt!", tt_map_bang, 0);
> }
> pigeon%
> 
> pigeon% ruby -rtt -e 'a = [1, 3, 4, 2]; a.tt!; p a'
> -e:1: warning: received 1
> -e:1: warning: received 3
> -e:1: warning: received 4
> -e:1: warning: received 2
> [true, false, false, true]
> pigeon% 
> 
> 
> 
> Guy Decoux
>