generate a "prelude" from `java_package`

[Niko Matsakis]

It's annoying to import all the FooExt traits manually. Let's create a "prelude", I .. guess for each java package?

Then you can do something like

duchess::java_package! {
    package foo.bar;
}

use foo::bar::prelude::*;

If we include the subpackages too, then you can do

use duchess::java::prelude::*;
use foo::prelude::*;

which would be nice.

[Niko Matsakis]

Mentoring tips

Tokens for a package are created here:

duchess/macro/src/codegen.rs

Lines 51 to 56 in a23cf56

 fn to_tokens( 
     &self, 
     parents: &[Id], 
     root_map: &RootMap, 
     reflector: &mut Reflector, 
 ) -> Result<TokenStream, SpanError> { 

You will need to modify that to generate a pub mod prelude with pub use statements for the Ext traits. But you'll also need to modify the code that generates a class declaration to return back a list of Ext traits and collect them here.

To include subpackages, you'd need to return the Ext traits from SpannedPackageInfo::to_tokens and collect them here.

[Niko Matsakis]

This is no longer relevant as we are using inherent method dispatch.