# Designing Namespaces

**URL:** <https://www.ruby-forum.com/t/designing-namespaces/134520>\
**Category:** Ruby\
**Created:** [April 11, 2008, 5:28pm UTC](https://www.ruby-forum.com/t/designing-namespaces/134520 "2008-04-11T17:28:47Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Trans](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/dfb087/32.png) [@Trans](https://www.ruby-forum.com/u/Trans)\
**Post date:** [April 11, 2008, 5:28pm UTC](https://www.ruby-forum.com/t/designing-namespaces/134520/1 "2008-04-11T17:28:47Z")

</div>

I find it curious that whenever I design an application and begin to  
organize the class/module namespaces, I get something like:

module FooMusic

```
class Instruments::WindInstruments::Trumpet < WindInstrument

class Instruments::WindInstruments::Clarinet < WindInstrument

class Instruments::StringInstruments::Violin < StringInstrument

```

Which seems very nice for explicitness, But then, of course, I think  
it’s way too wordy. So I’ll scale it back to something, that doesn’t  
read as nice, but is nonetheless more concise.

module FooMusic

```
class Instruments::Winds::Trumpet < WindInstrument

class Instruments::Winds::Clarinet < WindInstrument

class Instruments::Strings::Violin < StringInstrument

```

But then I start to think, what does all this hierarchy matter? Is  
anyone ever going to ‘include Instruments’? I call YAGNI on myself.  
Save some bytes and typing and end up with:

module FooMusic

```
class Trumpet < WindInstrument

class Clarinet < WindInstrument

class Violin < StringInstrument

```

And honestly I’m pretty happy with that, except… Have classes other  
than instruments in the app, say Musician and Orchestra, then I run  
into two sore spots:

1. If file names reflect module/class, then file organization gets  
messy. Eg.

foomusic/clarinet  
foomusic/musician  
foomusic/orchestra  
foomusic/trumpet  
foomusic/violin

So I tend to want to organize the actual files according to category  
(as in the earlier module organization):

foomusic/instruments/wind/trumpet  
foomusic/instruments/wind/clarinet  
foomusic/instruments/string/violin  
foomusic/players/musician  
foomusic/players/orchestra

That’s okay, I can live without that general correspondence between  
namespace and file name. But…

1. The RDocs aren’t sorted by subclass, so organization is messy there  
too. And I feel much worse about this one because documentation is so  
important. However, I keep telling myself “don’t code to the docs”.  
Not sorting by subclass is a lack of RDocs, and not something I should  
compensate for in my library design.

What are other people experiences with all this? Do you find it better  
use highly categorized namespaces and to stick with namespace/filename  
mapping? Or have you too found alternates organizations you prefer?

Thanks,  
T.

---

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**Author:** ![Trans](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/dfb087/32.png) [@Trans](https://www.ruby-forum.com/u/Trans)\
**Post date:** [April 11, 2008, 6:30pm UTC](https://www.ruby-forum.com/t/designing-namespaces/134520/2 "2008-04-11T18:30:01Z")

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On Apr 11, 2008, at 9:28 AM, Trans wrote:

> What are other people experiences with all this? Do you find it better  
> use highly categorized namespaces and to stick with namespace/filename  
> mapping? Or have you too found alternates organizations you prefer?
> 
> Thanks,

child classes should be inner classes - saves a ton of typing

class WindInstrument

class Trumpet \< WindInstrument  
end

class Carinet \< WindInstrument  
end

end

and then use shortcuts

def Music.trumpet \*a, &b

if a.empty? and b.nil?

```
 WindInstrument::Trumpet

```

else

```
WindInstrument::Trumpet.new *a, &b

```

end

trumpet = Music.trumpet(arg, arg){ block }

so the two main concepts are:

- nest classes under parent
- assign shortcuts

i’m not strict with that - but both are useful for maintaining  
sanity. i esp like

children = Parent.constants.select{|c| Parent \> Parent.const\_get(c)}

not that code - but you get the idea

a @ [http://codeforpeople.com/](http://codeforpeople.com/)

---

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**Author:** ![Trans](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/dfb087/32.png) [@Trans](https://www.ruby-forum.com/u/Trans)\
**Post date:** [April 11, 2008, 7:14pm UTC](https://www.ruby-forum.com/t/designing-namespaces/134520/3 "2008-04-11T19:14:50Z")

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On Fri, Apr 11, 2008 at 6:29 PM, ara.t.howard [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
wrote:

> ```
> WindInstrument::Trumpet
> 
> ```
> 
> not that code - but you get the idea

Very interesting approach Ara, allow me to express some skepticism  
about the shortcut delivering either the class or an instance of it.  
The idea is sure enough brilliant as a solution to name pollution, I  
wonder however if it is not a maintenance trap…  
Now if it became a well known pattern this danger would go away. In  
order to easier recognize the pattern I would suggest to use  
Capitalized names for your shortcut/factory methods. How does that feel?

Cheers  
Robert

–  
[http://ruby-smalltalk.blogspot.com/](http://ruby-smalltalk.blogspot.com/)

* * *

Whereof one cannot speak, thereof one must be silent.  
Ludwig Wittgenstein

---

<div class="post-metadata">

**Author:** ![Trans](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/dfb087/32.png) [@Trans](https://www.ruby-forum.com/u/Trans)\
**Post date:** [April 14, 2008, 12:48am UTC](https://www.ruby-forum.com/t/designing-namespaces/134520/4 "2008-04-14T00:48:05Z")

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> And I feel much worse about this one because documentation is so important.

Yes documentation is important, especially about teaching other people,  
or showing them how this is supposed to be used (and even better how it  
is designed and why, if there is enough space and time to do so, in a  
brief and concise manner) - but a documentation tool should not come  
into one’s way to think and design in my humble opinion. The current way  
leaves some things to be desired with rdoc - one example I found  
peculiar is that a .rb file of rake had about 6 methods. And ALL methods  
had # :nodoc: assigned and exactly 0 lines of other docu. I think this  
is somewhat sub-optimal as solution to think about documentation this  
way, that the first line of thought is wrapped towards the tool rather  
than other people (but just to get it out too, i think having rdoc is a  
lot better than not having it)

---

<div class="post-metadata">

**Author:** ![Trans](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/dfb087/32.png) [@Trans](https://www.ruby-forum.com/u/Trans)\
**Post date:** [April 13, 2008, 3:37am UTC](https://www.ruby-forum.com/t/designing-namespaces/134520/5 "2008-04-13T03:37:28Z")

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On Apr 11, 2008, at 11:13 AM, Robert D. wrote:

> Very interesting approach Ara, allow me to express some skepticism  
> about the shortcut delivering either the class or an instance of it.  
> The idea is sure enough brilliant as a solution to name pollution, I  
> wonder however if it is not a maintenance trap…  
> Now if it became a well known pattern this danger would go away. In  
> order to easier recognize the pattern I would suggest to use  
> Capitalized names for your shortcut/factory methods. How does that  
> feel?

i’ve gone back and forth a few times

Foo.Bar

throws my brain for a loop though, so i’ve tended toward

```
Alib.util.snakecase 'FooBar'

```

but i’m not religious about it…

cheers.

a @ [http://codeforpeople.com/](http://codeforpeople.com/)