Re: Disgusted with kbuild developers

["Eric S. Raymond" <esr@thyrsus.com>]

Alan Cox <alan@lxorguk.ukuu.org.uk>:
> You can force a side effect in both directions. The language provides the
> information to do that, the current -toolset- can't handle this.
> 
> At any point you ask a question you can "wind back" and compute the set
> of changes that are needed and re-ask only the needed questions.

I spent over a month in early 2000 trying a similar approach.  I tried it
with CML1, and I tried it with increasingly enriched dialects of CML1
(magic comments carrying extra semantic information, that sort of thing).

The results were (a) ugly, and (b) broken.  I struggled against this
for a long time, because I knew what a horrible revolving bitch and
maintaining a parallel rulebase in a new formalism was going to be.

As you no doubt realize, the problem of deducing the forcing
information from CMl1 markup is efectively equivalent to the problem
of writing a mechanical CML1-to-CML2 translator.  So I have a
suggestion: if you want to prove that it's possible to extract all the
info for side-effect forcing from CML1, do it by writing such a
translator.

I believe you will fail, as I did and as Jeff Garzik implicitly predicted.
If you fail, the process will teach you what I had to learn the hard way 
two years back.  If you succeed, people who are whingeing about wanting
a bug-for-bug rulebase translation will get what they want.

Don't tell me to do it.  Been there, done that, have the battle scars.
If there were any way I could have avoided maintaining my own rulebase,
you better believe I'd have done it.
-- 
		<a href="http://www.tuxedo.org/~esr/">Eric S. Raymond</a>