nested module problem

[Moritz Maxeiner via Digitalmars-d-learn]

On Saturday, 2 September 2017 at 21:24:19 UTC, Jean-Louis Leroy 
wrote:
> On Saturday, 2 September 2017 at 20:48:22 UTC, Moritz Maxeiner 
> wrote:
>> So the compiler wants you to import it by the name it has 
>> inferred for you (The fix being either specifying the module 
>> name in foo/bar.d as `module foo.bar`, or importing it as via 
>> `import bar;` in foo.d).
>> [1] https://dlang.org/spec/module.html
>
> I thought of doing that, it merely changed the error. OK now I 
> have:
>
> in foo.d:
> module foo;
> import foo.bar;
>
> in foo/bar.d:
> module foo.bar;
>
> $ dmd -c foo.d foo/bar.d
> foo/bar.d(1): Error: package name 'foo' conflicts with usage as 
> a module name in file foo.d
>
> If I compile separately:
> jll at ORAC:~/dev/d/tests/modules$ dmd -I. -c foo.d
> foo/bar.d(1): Error: package name 'foo' conflicts with usage as 
> a module name in file foo.d

Yes, these now both fail because you cannot have a module `foo` 
and a package `foo` at the same time (they share a namespace), I 
forgot about that.

> jll at ORAC:~/dev/d/tests/modules$ dmd -I. -c foo/bar.d

(same as before, no issue here)

>
> It believes that 'foo' is a package...because there is a 'foo' 
> directory?

You created the 'foo' package by specifying `module foo.bar` in 
foo/bar.d.

>
> I see that a workaround is to move foo.d to foo/package.d but I 
> would like to avoid that.

AFAIK you can't; consider:

-- baz.d ---
import foo;
------------

in the same directory as foo.d. If foo/package.d exists (with 
`module foo` inside), what should baz.d import? foo.d or 
foo/package.d?
The point being that we could have either used foo/package.d or 
foo.d for a package file, but not both (as that would allow 
ambiguity) and package.d was chosen.

[1] https://dlang.org/spec/module.html#package-module