[Issue 12014] New: package.d behaves suspiciously (and there are no docs)

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https://d.puremagic.com/issues/show_bug.cgi?id=12014

           Summary: package.d behaves suspiciously (and there are no docs)
           Product: D
           Version: D2
          Platform: x86_64
        OS/Version: Linux
            Status: NEW
          Severity: major
          Priority: P2
         Component: DMD
        AssignedTo: nobody at puremagic.com
        ReportedBy: lmb at stackedboxes.org


--- Comment #0 from Leandro Motta Barros <lmb at stackedboxes.org> 2014-01-27 14:56:47 PST ---
The "package.d" feature behaves strangely. It seems that the root of the issues
is the way fully-qualified names work when using package.d. Since there is no
proper documentation (only DIP37 and the changelog), there is no way to know
wether the current behvior is a bug or not.

Here are two examples showing what is perceived as improper (or, at least,
suspicious) behaviour:


EXAMPLE 1: Trying to simply replace the old "all.d" idiom with package.d
doesn't work out-of-the-box:

Originally, I had something like this:

 // mylib/util.d:
 module mylib.util;
 class Foo { }

 // mylib/all.d:
 module mylib.all;
 public import mylib.util;

 // main.d:
 import mylib.all;
 void main()
 {
    auto f = new mylib.util.Foo;
 }

And this used to work. Now, I added a new file:

 // package.d
 module mylib;
 public import mylib.util;

And changed the 'import' in the main one:

 // main.d
 import mylib;

 void main()
 {
    auto f = new mylib.util.Foo;
 }

Now, the compiler complains:

 main.d(5): Error: undefined identifier 'util'
 main.d(5): Error: mylib.util.Foo is used as a type

[Using mylib.Foo instead of mylib.util.Foo works -- which makes sense when
thnking about the use case of using package.d to split a large package into
smaller ones. ]

---------------------

EXAMPLE 2: Inconsistency with fully-qualified names

// mylib/util.d
module mylib.util;
class Foo { }

// mylib/package.d
module mylib;
public import mylib.util;

// main.d
import std.stdio;
import mylib;

void main()
{
   auto f = new mylib.Foo;
   writefln("%s", f.classinfo.name);
}

This prints 'mylib.util.Foo'. So far so good, that's the name I originally
expected.

Then I try to instantiate a 'Foo' using this very fully-qualified name the
compiler told me:

   auto f = new mylib.util.Foo;

And DMD doesn't like it anymore:

main.d(6): Error: undefined identifier 'util'
main.d(6): Error: mylib.util.Foo is used as a type

[This looks very much like a bug for me. The name given by classinfo.name
should be usable to instantiate a class, shouldn't it? ]

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