From: Gary Wright <gwtmp01@...>
Date: 2009-12-31T08:00:19+09:00
Subject: Re: Object.send(:remove_const, :Polygon)

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On Dec 30, 2009, at 5:47 PM, Ralph Shnelvar wrote:
> Consider
>=20
>=20
> irb(main):001:0> class X
> irb(main):002:1> end
> =3D> nil
> irb(main):003:0>
> irb(main):004:0* class Y < X
> irb(main):005:1> end
> =3D> nil
> irb(main):006:0>
> irb(main):007:0* Object.send(:remove_const, :X)
> =3D> X
> irb(main):008:0>
> irb(main):009:0* X.class
> NameError: uninitialized constant X
>         from (irb):9
>         from :0
> irb(main):010:0> Y.class
> =3D> Class
> irb(main):011:0> Y.superclass
> =3D> X
> irb(main):012:0> Y.superclass.superclass
> =3D> Object
> irb(main):013:0>
>=20
>=20
> How can the class X still exist when it has been removed?????

remove_const doesn't destroy the class object it just deletes the =
binding represented by the constant.

Ruby arranges for a class to have a name (a string label) that matches =
the first constant that the class is bound to.  The name still remains =
even if the constant binding is removed (via remove_const).

?> a =3D Class.new
=3D> #<Class:0x124b6ec>
>> a.name
=3D> ""
>> Foobar =3D a
=3D> Foobar
>> a.name
=3D> "Foobar"
>> Object.send(:remove_const, :Foobar)
=3D> Foobar
>> Foobar
NameError: uninitialized constant Foobar
	from (irb):31
>> a.name
=3D> "Foobar"
>> a.inspect
=3D> "Foobar"



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