I was wondering what the general consesus was (if there is one) on whether it's valuable to always put module declarations in each module.

Obviously, if you need the module to have a name other than the file name, then you need to have the module declaration. However, is it necessarily desirable to have it when the module name matches the file name? Or would there even be a reason for it to be desirable _not_ to have the module declaration?

I can't think of any particularly strong reasons to have it or not to have it. My first reaction is to just always use it, but thinking about it, I'm not sure that there's really much point if the file name and the module name already match. Does anyone have reasons why it would matter other than personal preference?

- Jonathan M Davis

On 15.07.2010 00:22, Jonathan M Davis wrote:
> I was wondering what the general consesus was (if there is one) on whether it's
> valuable to always put module declarations in each module.
>
> Obviously, if you need the module to have a name other than the file name, then
> you need to have the module declaration. However, is it necessarily desirable to
> have it when the module name matches the file name? Or would there even be a
> reason for it to be desirable _not_ to have the module declaration?
>
> I can't think of any particularly strong reasons to have it or not to have it.
> My first reaction is to just always use it, but thinking about it, I'm not sure
> that there's really much point if the file name and the module name already
> match. Does anyone have reasons why it would matter other than personal
> preference?

Some of the D build tools complain if you don't use module declarations.  And IIRC, modules in subdirectories (packages) need to have them.  So I end up adding them for anything but single-file test programs.

I was wondering what the general consesus was (if there is one) on whether
>> it's
>> valuable to always put module declarations in each module.
>>
>

> I can't think of any particularly strong reasons to have it or not to have
>> it.
>> My first reaction is to just always use it, but thinking about it, I'm not
>> sure
>> that there's really much point if the file name and the module name
>> already
>> match. Does anyone have reasons why it would matter other than personal
>> preference?
>>
>
>
I can see two reasons to use module declarations:

- you can put documentation comments before the module declaration, to have them at the beginning of the docs. That's where you put general indications on the use of this module, and copyright/author/license indications. I quite like these module-level docs, personally.

- it defines a new symbol, which you can use in template with alias
parameters and __traits, like in __traits(allMembers, moduleName). If you're
into compile-time introspection, that can be useful.
(though maybe these symobols exist even without module decls, I don't know).


Philippe