From: ts <decoux@...>
Date: 2003-12-10T00:29:36+09:00
Subject: Re: passing a func to a ruby func

>>>>> "e" == elathan  <elathan@phys.uoa.gr> writes:

e> Can I export a function such as qsort() of the Linux stdlib to a Ruby
e> method. qsort() takes a C function pointer as a parameter. 

 Not really understood what you want to do, but for qsort a stupid example 

svg% cat aa.c
#include <ruby.h>

static int
aa_sort(const void *va, const void *vb)
{
    if (rb_block_given_p()) {
        return NUM2INT(rb_yield(rb_assoc_new(*(VALUE *)va, *(VALUE *)vb)));
    }
    return NUM2INT(rb_funcall(*(VALUE *)va, rb_intern("<=>"), 1, 
                              *(VALUE *)vb));
}

static VALUE
aa_qsort(VALUE obj, VALUE a)
{
    a = rb_Array(a);
    qsort(RARRAY(a)->ptr, RARRAY(a)->len, sizeof(VALUE), aa_sort);
    return a;
}



void Init_aa()
{
    rb_define_global_function("qsort!", aa_qsort, 1);
}
svg%
 
svg% ruby -raa -e 'p qsort!([3,6,8,1,0])'
[0, 1, 3, 6, 8]
svg%
 
svg% ruby -raa -e 'p qsort!([3,6,8,1,0]) {|a, b| b <=> a}'
[8, 6, 3, 1, 0]
svg% 


Guy Decoux