[MLton] MLB path variables and path maps

[Stephen Weeks]

> I'm not sure that version number information is the kind of
> information that should be put into MLB files.

I agree.  I think it belongs in the packaging system, and implicit in
MLB files.

> At any rate, I think that it is important to have a system that
> allows you to say things explicitly and precisely. More elaborate
> systems can be built on top of such a system (e.g. generate the
> config MLB file (substituting specific paths) based on package
> dependencies).

I could see that as a clean way to go.

> I don't see how the current system would offer better support in
> this respect. As far as I can see, the current handling of path
> variables is too simple as basis to erect a package system upon.

Maybe.  Let's move the packaging system discussion over to the new
thread I just started.

> Could you elaborate your thoughts on packaging systems. 

An excellent request :-).

> How does your idea of a package system differ from the existing
> package systems (e.g.  Debian, Red Hat)? Would SML libraries
> ultimately be installed through the existing package systems or
> would we need a completely new system for them?

I think we need our own (new) system that works portably across all
the systems we run on.