Asp Forum - Namespace conflict resolution

Dema

7/12/2005 7:52:00 PM

Hi guys,

This question is better explained with an example:

I have the standard File class, right? Suppose I define another File
class within my own namespace:

module MyNamespace
class File
...
end
end

Now, if I am on an irb session and I want to refer to my
MyNamespace::File class using only the short form 'File', I would do:
include MyNamespace

How does Ruby decide which class to use when I reference 'File' in this
scope? (I've already tested and the original 'File' class is the chosen
class)

How would I be able to temporarely replace the standard 'File' class in
the global Object namespace with my own File class and then revert it
back to the standard when I'm done?

rgds
Dema
http://dema.r...

3 Answers

Berger, Daniel

7/12/2005 8:01:00 PM

Dema wrote:
> Hi guys,
>
> This question is better explained with an example:
>
> I have the standard File class, right? Suppose I define another File
> class within my own namespace:
>
> module MyNamespace
> class File
> ...
> end
> end
>
> Now, if I am on an irb session and I want to refer to my
> MyNamespace::File class using only the short form 'File', I would do:
> include MyNamespace
>
> How does Ruby decide which class to use when I reference 'File' in this
> scope? (I've already tested and the original 'File' class is the chosen
> class)
>
> How would I be able to temporarely replace the standard 'File' class in
> the global Object namespace with my own File class and then revert it
> back to the standard when I'm done?
>
> rgds
> Dema
> http://dema.r...

My general response would be: don't do that. My personal experience is
that slapping existing Ruby classes under your own namespace is a bad
idea. It's just a pain. The fact that you're trying to use the "short
form" only reinforces that it's unnecessary.

Just put your methods directly in the File class without the added
namespace.

Regards,

Dan

Dema

7/12/2005 9:10:00 PM

Unfortunately, I can't do that.

Both the class definitions and the code that's going to use the short
form of the classes are evaluated during runtime, so it's basically a
environment where the power user can define and use new classes.

I want this runtime evaluation to occur in a sandbox, without
interference or conflicts from the standard class names, but I don't
want to obligate the user to use the long names for the namespaced
classes.

I hope I am being clear here.

rgds
Dema

Daniel Berger wrote:
> Dema wrote:
> > Hi guys,
> >
> > This question is better explained with an example:
> >
> > I have the standard File class, right? Suppose I define another File
> > class within my own namespace:
> >
> > module MyNamespace
> > class File
> > ...
> > end
> > end
> >
> > Now, if I am on an irb session and I want to refer to my
> > MyNamespace::File class using only the short form 'File', I would do:
> > include MyNamespace
> >
> > How does Ruby decide which class to use when I reference 'File' in this
> > scope? (I've already tested and the original 'File' class is the chosen
> > class)
> >
> > How would I be able to temporarely replace the standard 'File' class in
> > the global Object namespace with my own File class and then revert it
> > back to the standard when I'm done?
> >
> > rgds
> > Dema
> > http://dema.r...
>
> My general response would be: don't do that. My personal experience is
> that slapping existing Ruby classes under your own namespace is a bad
> idea. It's just a pain. The fact that you're trying to use the "short
> form" only reinforces that it's unnecessary.
>
> Just put your methods directly in the File class without the added
> namespace.
>
> Regards,
>
> Dan

Gennady

7/12/2005 10:55:00 PM

You can evaluate the code to be run in a sandbox in the binding of a
module you defined your own File class in (see eval, module_eval). To
refer to a standard class you will have to use ::File from there.

Gennady.

Dema wrote:
> Unfortunately, I can't do that.
>
> Both the class definitions and the code that's going to use the short
> form of the classes are evaluated during runtime, so it's basically a
> environment where the power user can define and use new classes.
>
> I want this runtime evaluation to occur in a sandbox, without
> interference or conflicts from the standard class names, but I don't
> want to obligate the user to use the long names for the namespaced
> classes.
>
> I hope I am being clear here.
>
> rgds
> Dema
>
> Daniel Berger wrote:
>
>>Dema wrote:
>>
>>>Hi guys,
>>>
>>>This question is better explained with an example:
>>>
>>>I have the standard File class, right? Suppose I define another File
>>>class within my own namespace:
>>>
>>>module MyNamespace
>>> class File
>>> ...
>>> end
>>>end
>>>
>>>Now, if I am on an irb session and I want to refer to my
>>>MyNamespace::File class using only the short form 'File', I would do:
>>>include MyNamespace
>>>
>>>How does Ruby decide which class to use when I reference 'File' in this
>>>scope? (I've already tested and the original 'File' class is the chosen
>>>class)
>>>
>>>How would I be able to temporarely replace the standard 'File' class in
>>>the global Object namespace with my own File class and then revert it
>>>back to the standard when I'm done?
>>>
>>>rgds
>>>Dema
>>>http://dema.r...
>>
>>My general response would be: don't do that. My personal experience is
>>that slapping existing Ruby classes under your own namespace is a bad
>>idea. It's just a pain. The fact that you're trying to use the "short
>>form" only reinforces that it's unnecessary.
>>
>>Just put your methods directly in the File class without the added
>>namespace.
>>
>>Regards,
>>
>>Dan
>
>
>

comp.lang.ruby

Namespace conflict resolution

Dema

Berger, Daniel

Dema

Gennady

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