/*
 *  call-seq:
 *     module_function(symbol, ...)    => self
 *  
 *  Creates module functions for the named methods. These functions may
 *  be called with the module as a receiver, and also become available
 *  as instance methods to classes that mix in the module. Module
 *  functions are copies of the original, and so may be changed
 *  independently. The instance-method versions are made private. If
 *  used with no arguments, subsequently defined methods become module
 *  functions.
 *     
 *     module Mod
 *       def one
 *         "This is one"
 *       end
 *       module_function :one
 *     end
 *     class Cls
 *       include Mod
 *       def callOne
 *         one
 *       end
 *     end
 *     Mod.one     #=> "This is one"
 *     c = Cls.new
 *     c.callOne   #=> "This is one"
 *     module Mod
 *       def one
 *         "This is the new one"
 *       end
 *     end
 *     Mod.one     #=> "This is one"
 *     c.callOne   #=> "This is the new one"
 */

static VALUE
rb_mod_modfunc(argc, argv, module)
    int argc;
    VALUE *argv;
    VALUE module;
{
    int i;
    ID id;
    NODE *body;

    if (TYPE(module) != T_MODULE) {
        rb_raise(rb_eTypeError, "module_function must be called for modules");
    }

    secure_visibility(module);
    if (argc == 0) {
        SCOPE_SET(SCOPE_MODFUNC);
        return module;
    }

    set_method_visibility(module, argc, argv, NOEX_PRIVATE);
    for (i=0; i<argc; i++) {
        VALUE m = module;

        id = rb_to_id(argv[i]);
        for (;;) {
            body = search_method(m, id, &m);
            if (body == 0) {
                body = search_method(rb_cObject, id, &m);
            }
            if (body == 0 || body->nd_body == 0) {
                rb_bug("undefined method `%s'; can't happen", rb_id2name(id));
            }
            if (nd_type(body->nd_body) != NODE_ZSUPER) {
                break;                /* normal case: need not to follow 'super' link */
            }
            m = RCLASS(m)->super;
            if (!m) break;
        }
        rb_add_method(rb_singleton_class(module), id, body->nd_body, NOEX_PUBLIC);
    }
    return module;
}