Re: Is smartness the problem?

From	anton@mips.complang.tuwien.ac.at (Anton Ertl)
Newsgroups	comp.lang.forth
Subject	Re: Is smartness the problem?
Date	2012-07-14 11:53 +0000
Organization	Institut fuer Computersprachen, Technische Universitaet Wien
Message-ID	<2012Jul14.135307@mips.complang.tuwien.ac.at> (permalink)
References	<m75h1o.ide@spenarnc.xs4all.nl>

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Albert van der Horst <albert@spenarnc.xs4all.nl> writes:
>Recently we had a discussion about formatting.
>The basic idea is:
>
>AVAILABLE "HOST" GET-ENV
>"The computer %s has %d bytes available"  FORMAT&TYPE
>
>What FORMAT&TYPE does is
...
>3. EXECUTE s , which gives a string, collect that string
...
>Alternative implementations are now
>1. once you find the string  "s" or "d"  evaluate it
>   with the formatters at the top of the search order.
>2. Use SEARCH-WORD-LIST and EXECUTE

In 3. you say that you EXECUTE it, so EVALUATE (1.) is out.

>I've been bitten hard by a problem caused by using 1
>and the existance of STATE. There is no smart
>word in sight, but it smells the same.
>
>I want to add the phrase
>" ^%s @ %d  +" to a method definition, where at %s
>the name of the class is to be filled in and at %d
>the offset of the field where the method is supposed to
>work.
>The string e.g. "^VECTOR @  4 + " has to be evaluated in
>compilation mode.
>
>However I got the string "^ @ +". It took me some time
>to realize that evaluating "s" in compilation mode,
>merely added s to the current definition, and did nothing
>to end up in the collected string.
>
>So, I wonder what wise lessons concerning STATE I missed
>to get into this trouble.

EVALUATE does not work in general for most of the things that people
want to do with it (but it appears to work for simple cases), because
it uses a lot of context that people do not want in general (at least
not at EVALUATE run-time, when it is used by EVALUATE).  STATE is
among that context.

- anton
-- 
M. Anton Ertl  http://www.complang.tuwien.ac.at/anton/home.html
comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
     New standard: http://www.forth200x.org/forth200x.html
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Is smartness the problem? Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-14 12:22 +0000
  Re: Is smartness the problem? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-14 11:53 +0000
  Re: Is smartness the problem? Bernd Paysan <bernd.paysan@gmx.de> - 2012-07-14 15:26 +0200

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