[m-dev.] shims

[Paul Bone]

On Tue, Sep 16, 2014 at 05:16:34AM +0200, Zoltan Somogyi wrote:
> 
> 
> On Tue, 16 Sep 2014 12:05:25 +1000, Peter Wang <novalazy at gmail.com> wrote:
> > Hmm, it should be possible to qualify names within a branch,
> > but if "branch sub-modules" are unnamed then it's a bit hard to do.
> 
> I suspect that "a bit hard to do" is WAY, WAY underestimating
> the difficulty of implementing the proposals in this thread.
> 
> The compiler's current handling of the item list is much more
> complicated than it seems. I tried to clean it up once, and failed.
> I thought it should have been simple to replace the current
> item list with a list of modules in which each module contains
> a list of submodules and a list of items that were not :- module
> or :- end_module. Even this was far from simple. Most of the
> problems I bumped into were caused by parts of the compiler
> seeming requiring the maintenance of invariants that were
> undocumented, and did not live anywhere except in Fergus's head
> (and which I am pretty sure don't live there anymore either).
> Some of these involved the handling of import_statuses,
> about whose complexities Paul should be able to report
> in more detail, as the last person to look into that nest of vipers :-(

That is indeed a nest of vipers.  It is not something I've found the 5 or
more days without ANY distractions to do.  I've stop-started work on it a
number of times and each time I forget all the peices that were in my mind
the last time I worked on it.  Until I 1) have the right amount of time set
asside for it and 2) (and more difficult) have nothing better to do then
it's going to stay in the "maybe one day" pile of tasks.

> If someone wanted to implement any of these proposals
> without first cleaning up the handling of item lists, there are
> only two outcomes:
> 
> - They fail, probably after a lot of work. This is bad.
> 
> - They succeed, after even more work. This is even worse,
>   as it means that whoever DOES clean up that code later,
>   will have more code to clean up, and until then, subtle bugs
>   have more places to hide.
> 
> You may think I am joking. I am not.

I feel the same about the import_status change.


-- 
Paul Bone