index

/*
 *  call-seq:
 *     array.index(obj)   ->  int or nil
 *  
 *  Returns the index of the first object in <i>self</i> such that is 
 *  <code>==</code> to <i>obj</i>. Returns <code>nil</code> if
 *  no match is found.
 *     
 *     a = [ "a", "b", "c" ]
 *     a.index("b")   #=> 1
 *     a.index("z")   #=> nil
 */

static VALUE
rb_ary_index(ary, val)
    VALUE ary;
    VALUE val;
{
    long i;

    for (i=0; i<RARRAY(ary)->len; i++) {
        if (rb_equal(RARRAY(ary)->ptr[i], val))
            return LONG2NUM(i);
    }
    return Qnil;
}