# Module children
**URL:** https://rubytalk.org/t/module-children/57221
**Category:** ruby-talk
**Created:** [1 February 2010 19:50 UTC](https://rubytalk.org/t/module-children/57221 "2010-02-01T19:50:34Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@Camille\_Cr](https://rubytalk.org/u/Camille_Cr)
#### Post date: [1 February 2010 19:50 UTC](https://rubytalk.org/t/module-children/57221/1 "2010-02-01T19:50:34Z")
Hello,
I'd like to get the list of all the classes contained in a module.
What's the simple way to do that?
Thank you
> **路路路**
>
> --
> Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/).
---
### Author:  [@August\_Lilleaas](https://rubytalk.org/u/August_Lilleaas)
#### Post date: [1 February 2010 21:05 UTC](https://rubytalk.org/t/module-children/57221/2 "2010-02-01T21:05:06Z")
Here's a quick and dirty implementation using ObjectSpace
module LibraryWrapperThing
class UtilityClassA; end
class Fish; end
class Dog; end
end
class NotMe; end
classes =
ObjectSpace.each\_object do |obj|
classes \<\< obj if Module === obj
end
p classes.select {|c| c.name =~ /^LibraryWrapperThing:馃槙 }
# =\> [LibraryWrapperThing::Dog, LibraryWrapperThing::Fish, ...]
> **路路路**
>
> On Feb 1, 8:50 pm, Camille Roux \ wrote:
>
> > Hello,
> >
> > I'd like to get the list of all the classes contained in a module.
> > What's the simple way to do that?
> >
> > Thank you
> > --
> > Posted viahttp://www.ruby-forum.com/.
---
### Author:  [@Aaron\_Patterson1](https://rubytalk.org/u/Aaron_Patterson1)
#### Post date: [1 February 2010 21:06 UTC](https://rubytalk.org/t/module-children/57221/3 "2010-02-01T21:06:57Z")
> Hello,
>
> I'd like to get the list of all the classes contained in a module.
> What's the simple way to do that?
> > module Foo; A = 1; class B; end; module C; end end
=\> nil
> > Foo.constants.find\_all { |k| Class === Foo.const\_get(k) }
=\> ["B"]
> **路路路**
>
> On Tue, Feb 02, 2010 at 04:50:34AM +0900, Camille Roux wrote:
>
> --
> Aaron Patterson
> [http://tenderlovemaking.com/](http://tenderlovemaking.com/)
---
### Author:  [@August\_Lilleaas](https://rubytalk.org/u/August_Lilleaas)
#### Post date: [1 February 2010 21:10 UTC](https://rubytalk.org/t/module-children/57221/4 "2010-02-01T21:10:11Z")
+1 馃檪
> **路路路**
>
> On Feb 1, 10:06 pm, Aaron Patterson \ wrote:
>
> > \>\> module Foo; A = 1; class B; end; module C; end end
> > =\> nil
> > \>\> Foo.constants.find\_all { |k| Class === Foo.const\_get(k) }
> >
> > =\> ["B"]
---
### Author:  [@Ryan\_Davis1](https://rubytalk.org/u/Ryan_Davis1)
#### Post date: [1 February 2010 21:38 UTC](https://rubytalk.org/t/module-children/57221/5 "2010-02-01T21:38:56Z")
> > Hello,
> >
> > I'd like to get the list of all the classes contained in a module.
> > What's the simple way to do that?
>
> > > module Foo; A = 1; class B; end; module C; end end
>
> =\> nil
>
> > > Foo.constants.find\_all { |k| Class === Foo.const\_get(k) }
>
> =\> ["B"]
Personally, I usually map first:
> > Foo.constants.map { |s| Foo.const\_get s }.find\_all { |k| Class === k }
=\> [Foo::B]
> **路路路**
>
> On Feb 1, 2010, at 13:06 , Aaron Patterson wrote:
>
> > On Tue, Feb 02, 2010 at 04:50:34AM +0900, Camille Roux wrote:
---
### Author:  [@JEG2](https://rubytalk.org/u/JEG2)
#### Post date: [1 February 2010 21:55 UTC](https://rubytalk.org/t/module-children/57221/6 "2010-02-01T21:55:26Z")
> > > Hello,
> > >
> > > I'd like to get the list of all the classes contained in a module.
> > > What's the simple way to do that?
> >
> > > > module Foo; A = 1; class B; end; module C; end end
> >
> > =\> nil
> >
> > > > Foo.constants.find\_all { |k| Class === Foo.const\_get(k) }
> >
> > =\> ["B"]
>
> Personally, I usually map first:
>
> > > Foo.constants.map { |s| Foo.const\_get s }.find\_all { |k| Class === k }
>
> =\> [Foo::B]
Then you can switch the the under loved grep():
> > Foo.constants.map { |s| Foo.const\_get s }.grep(Class)
=\> [Foo::B]
James Edward Gray II
> **路路路**
>
> On Feb 1, 2010, at 3:38 PM, Ryan Davis wrote:
>
> > On Feb 1, 2010, at 13:06 , Aaron Patterson wrote:
> >
> > > On Tue, Feb 02, 2010 at 04:50:34AM +0900, Camille Roux wrote:
---
### Author:  [@Ryan\_Davis1](https://rubytalk.org/u/Ryan_Davis1)
#### Post date: [1 February 2010 22:34 UTC](https://rubytalk.org/t/module-children/57221/7 "2010-02-01T22:34:23Z")
Ah! I always forget about that one. Good catch.
> **路路路**
>
> On Feb 1, 2010, at 13:55 , James Edward Gray II wrote:
>
> > On Feb 1, 2010, at 3:38 PM, Ryan Davis wrote:
> >
> > > Personally, I usually map first:
> > >
> > > > > Foo.constants.map { |s| Foo.const\_get s }.find\_all { |k| Class === k }
> > >
> > > =\> [Foo::B]
> >
> > Then you can switch the the under loved grep():
> >
> > > > Foo.constants.map { |s| Foo.const\_get s }.grep(Class)
> >
> > =\> [Foo::B]