From: Eric Hodel <drbrain@...7.net>
Date: 2005-05-04T02:23:14+09:00
Subject: I rock.

Yup, rb_intern needs to be cached.  Yup, the __self thing is wrong (it 
was late, and I forgot about NODE_SELF).  No, it doesn't let you 
directly call C code either (yet?).

$ cat demo/factorial.rb
class F
   def factorial(n)
     f = 1
     n.downto(2) { |x| f *= x }
     return f
   end

   def main # horrid but funny hack
     return factorial(5)
   end
end
$ ./translate2.rb demo/factorial.rb > f.c
$ cc -dynamic -bundle -undefined suppress -flat_namespace  -g -O2 -pipe 
-fno-common -I /usr/local/lib/ruby/1.8/powerpc-darwin7.9.0 f.c -o 
F.bundle
$ ruby -I. -rF -e 'p F.new.factorial(5)'
120
$ time ruby -Idemo -rfactorial -e 'p F.new.factorial(9999)' > /dev/null

real    0m3.938s
user    0m3.360s
sys     0m0.080s
$ time ruby -I. -rF -e 'p F.new.factorial(9999)' > /dev/null

real    0m3.751s
user    0m3.340s
sys     0m0.060s

(but I don't expect a speed increase, the way it works)

$ cat f.c
// BEGIN METARUBY PREAMBLE
#include <ruby.h>
#define case_equal_long(x, y) (rb_funcall((x), rb_intern("==="), 1, 
(y)))
// END METARUBY PREAMBLE
// class F < Object

static VALUE
rrc_cF_factorial(VALUE __self, VALUE n) {
VALUE f;
VALUE x;
f = LONG2FIX(1);
x = n;
while (RTEST(rb_funcall(x, rb_intern(">="), 1, LONG2FIX(2)))) {
f = rb_funcall(f, rb_intern("*"), 1, x);
x = rb_funcall(x, rb_intern("-"), 1, LONG2FIX(1));
};
return f;
}

static VALUE
rrc_cF_main(VALUE __self) {
return rb_funcall(__self, rb_intern("factorial"), 1, LONG2FIX(5));
}

void
Init_F() {
VALUE rrc_cF = rb_define_class("F", rb_path2class("Object"));

rb_define_method(rrc_cF, "factorial", rrc_cF_factorial, 1);
rb_define_method(rrc_cF, "main", rrc_cF_main, 0);

}

-- 
Eric Hodel - drbrain@segment7.net - http://segment7.net
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