Re: What databases have taught me

From: Marshall <>
Date: 1 Jul 2006 11:40:11 -0700
Message-ID: <>

Dmitry A. Kazakov wrote:
> On 30 Jun 2006 15:59:54 -0700, Marshall wrote:
> >>>> 1. Why parsing need to be bottom-up?
> >>>
> >>> "bottom-up" is not the question; the question is context-free vs.
> >>> context sensitive.
> >>
> >> You should mean a grammar here. It is a different issue.
> >
> > *You* brought up parsing, not me. Or do you think that grammars and
> > parsing are unrelated?!
> It depends on what you parse. If you want to reserve the word "parsing" for
> formal grammars, then OK.

Well, that's the only way I've ever heard the word used in a CS context; I understood the usage to be universal. Are you saying it isn't?

> Replace "parsing" above with "matching" or
> "analysis" or "resolution." Let's not argue about wording.

Fair enough.

> > In any event, the issue you are raising is
> > one of context sensitivity, which, while occasionally practiced in
> > languages such as ADA and Perl, has been widely repudiated as
> > a bad idea.
> I have exactly the opposite view on this issue.


So, the probems with this approach are pretty well-known. Can you say what you consider to be the benefits? And perhaps also why these benefits outweigh the costs?

> BTW, if you wanted to be context-free at semantic (not syntax/grammar)
> level you'd have to abandon overloading and require all objects to have
> fully qualified distinct names, globally and locally distinct, note. I
> doubt, anybody would like such language.

Well, I disagree that overloading would be affected, but as for the rest, that is actually a decent point. Lexical scoping is exactly the same thing as context sensitive naming. I'll have to think about it.

Marshall Received on Sat Jul 01 2006 - 20:40:11 CEST

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