method

<=

v1_9_3_392 - Show latest stable - 1 note - Class: Module

<=(p1) public

Returns true if mod is a subclass of other or is the same as other. Returns nil if there’s no relationship between the two. (Think of the relationship in terms of the class definition: “class A<B” implies “A<B”).

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VALUE
rb_class_inherited_p(VALUE mod, VALUE arg)
{
    VALUE start = mod;

    if (mod == arg) return Qtrue;
    switch (TYPE(arg)) {
      case T_MODULE:
      case T_CLASS:
        break;
      default:
        rb_raise(rb_eTypeError, "compared with non class/module");
    }
    while (mod) {
        if (RCLASS_M_TBL(mod) == RCLASS_M_TBL(arg))
            return Qtrue;
        mod = RCLASS_SUPER(mod);
    }
    /* not mod < arg; check if mod > arg */
    while (arg) {
        if (RCLASS_M_TBL(arg) == RCLASS_M_TBL(start))
            return Qfalse;
        arg = RCLASS_SUPER(arg);
    }
    return Qnil;
}

January 11, 2010

0 thanks

Includes descendants

May be helpful to know that this returns true if A is any descendant of B, not just a direct one. As an example:

class Foo; end
class Bar < Foo; end
class Baz < Bar; end

Bar <= Foo #=> true
Baz <= Foo #=> true

<=

Related methods

Includes descendants