RE: [Axiom-developer] lattice

[Page, Bill]

Gaby, 

On Thursday, August 10, 2006 9:29 PM you wrote:
> ... 
> A project might be to have the compiler output spad
> dependencies --
> just like GCC is able to output dependencies, which greatly
> facilitates the tedious part of writing Makefiles and
> keeping them in sync; Automake uses it.
> 

Where you here "years ago" when we first discussed the fact
that Axiom's build dependencies form a digraph with loops?
That makes the problem of using Automake rather more
difficult, I think - not impossible, but one would still
have to manually define a set of "bootstrap" modules which
when removed from the graph, turn it into a lattice that
can be sorted. Tim Daly did this entirely manually as part
of the initial steps in making Axiom available as open source.
Prior to that it was always necessary to have a running
version of Axiom in order to build Axiom - and that was
considered by some people contrary to the intention of making
Axiom "fully available" as open source (i.e. without also
having to distribute a binary version).

Having software find a optimal minimal set of bootstrap
modules is an interest (open?) question.

What to actually do about the circular dependencies themselves
is, perhaps a separate, but interesting subject in it's own
right.

I am very interested in you opinions on this subject because
of your background with gcc which also involves a bootstrapping
process, although I think no circular dependencies, right?

Regards,
Bill Page.