really why module declarations?

[Adam D. Ruppe via Digitalmars-d-learn]

On Sunday, 26 March 2017 at 20:51:01 UTC, XavierAP wrote:
> I've perused both the spec[1] and Andrei's book, and I the idea 
> I get is that module declarations are optional, recommended 
> only in case of file names not being valid D names.

Module declarations are only optional in the most trivial case 
that is rarely useful in real world code. I recommend you ALWAYS 
use them (and always put a ddoc comment on them!), and moreover 
that you avoid top name modules (use `myproject.modname` instead 
of `modname`) to avoid conflicts.

If you don't, you are depending on implicit magic and just hoping 
that there's no conflict from third party libraries, and those 
lead to problems, almost guaranteed before long.

> if we have to be disciplined to keep it consistent with paths 
> anyway?

That's false, the path is irrelevant to the D language, ONLY the 
module declaration gives the canonical name. The path is just a 
helper for automatic tools to find the module given an import, 
but my preference is to ditch those things and actually just list 
your modules by name anyway. Then everything works reliably and 
consistently.