Method: Object#singleton_method

Defined in:
proc.c

#singleton_method(sym) ⇒ Object

Similar to method, searches singleton method only.

class Demo
  def initialize(n)
    @iv = n
  end
  def hello()
    "Hello, @iv = #{@iv}"
  end
end

k = Demo.new(99)
def k.hi
  "Hi, @iv = #{@iv}"
end
m = k.singleton_method(:hi)
m.call   #=> "Hi, @iv = 99"
m = k.singleton_method(:hello) #=> NameError



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# File 'proc.c', line 1903

VALUE
rb_obj_singleton_method(VALUE obj, VALUE vid)
{
    const rb_method_entry_t *me;
    VALUE klass = rb_singleton_class_get(obj);
    ID id = rb_check_id(&vid);

    if (NIL_P(klass) || NIL_P(klass = RCLASS_ORIGIN(klass))) {
      undef:
	rb_name_err_raise("undefined singleton method `%1$s' for `%2$s'",
			  obj, vid);
    }
    if (!id) {
        VALUE m = mnew_missing_by_name(klass, obj, &vid, FALSE, rb_cMethod);
        if (m) return m;
	goto undef;
    }
    me = rb_method_entry_at(klass, id);
    if (UNDEFINED_METHOD_ENTRY_P(me) ||
	UNDEFINED_REFINED_METHOD_P(me->def)) {
	vid = ID2SYM(id);
	goto undef;
    }
    return mnew_from_me(me, klass, klass, obj, id, rb_cMethod, FALSE);
}