snax

make false be true

Let’s be evil, and fake out false with some metaprogramming. We will do this by using method_missing to delegate identity methods to another object, namely, true.

meta meta meta

In Ruby there’s only one hard-coded false object. You can’t FalseClass.new to make a new, clean one. Even if you could, false’s singleton class (also known as metaclass) is strangely identical to its regular class:

irb(main):001:0> FalseClass == (class << false; self; end)
=> true

This is unlike Fixnum or Symbol, which don’t have singleton classes at all (see here for why).

There’s no way to retrieve regular false functionality after you do this, as far as I know.

even more meta meta

Anyone know why metametaclasses inherit the methods of metaclasses?

irb(main):001:0> require 'rubygems'; require 'metaid' #=> true
irb(main):002:0> a = "something" #=> "something"
irb(main):003:0> a.metaclass.instance_eval("def ok; true; end") #=> nil
irb(main):004:0> a.ok #=> NoMethodError
irb(main):005:0> a.class.ok #=> NoMethodError
irb(main):006:0> a.metaclass.ok #=> true
irb(main):007:0> a.metaclass.metaclass.ok #=> true

That doesn’t seem right. Shouldn’t the last one be NoMethodError?

postscript, which is not meta at all

Bee is on RedHanded today; hooray.