Proposal: module namespaces.

[Christian Brolin]

Malcolm Wallace wrote:
> 
> Simon Marlow wrote:
> 
> > The compiler finds the file because you tell it what the filename is.
> > That's the way it works now, and if I understand correctly Malcolm isn't
> > suggesting we change that (and I agree).
> 
> Yes, that's what I had in mind.  My guiding design principle is that
> I want absolutely minimal changes to the current way of doing things,
> while still managing to gain new expressiveness in the module namespace.
> 
> > There are really two issues here:
> >
> >   * how do you find a module to compile in the first place (not an
> >     issue for interpreters, only for batch compilers).  Just run
> >     the compiler giving it the filename.
> 
> Exactly.  When the dot-extended module name is explicitly given,
> in full, in the source file's "module" header, then it doesn't
> matter where the compiler is invoked from.
> 
>     cd .; ghc -c A/B/C/D.hs
>     cd A;   ghc -c B/C/D.hs
>     cd A/B;   ghc -c C/D.hs
>     CD A/B/C;   ghc -c D.hs
> 
> are all equivalent.  No special flags are required to tell the
> compiler that the "root" of this tree is at the parent of A.  The
> source file contains everything the compiler needs to know.

Yes, it is easy to find a module file given the filename, but how does
the compiler find modules that this module imports?

-- 
Christian Brolin