Re: CASE comparison values

From	JennyB <jennybrien@googlemail.com>
Newsgroups	comp.lang.forth
Subject	Re: CASE comparison values
Date	2012-01-23 09:11 -0800
Organization	http://groups.google.com
Message-ID	<32096725.1413.1327338699800.JavaMail.geo-discussion-forums@vbhn11> (permalink)
References	<dedb18b4-3a6e-4012-b0bd-ff017e5bdd1e@a8g2000pbi.googlegroups.com>

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Literals and constants are known at compile time, the results of expressions are not. If you avoid the latter then a CASE statement can be implemented behind the scenes as a jump table, otherwise it has to be equivalent to a nested IF ... ELSE, where each alternative has to be tested in turn until a match is found. 

In practice, x2 would almost always be known at compile time. I can't think of offhand of a useful CASE where it is not.

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CASE comparison values Percy <percival.andrews@gmail.com> - 2012-01-23 05:32 -0800
  Re: CASE comparison values Brad <hwfwguy@gmail.com> - 2012-01-23 07:57 -0800
    Re: CASE comparison values Aleksej Saushev <asau@inbox.ru> - 2012-01-23 22:23 +0400
  Re: CASE comparison values JennyB <jennybrien@googlemail.com> - 2012-01-23 09:11 -0800
    Re: CASE comparison values stephenXXX@mpeforth.com (Stephen Pelc) - 2012-01-23 18:38 +0000
      Re: CASE comparison values alberto pasquale <alberto@hal-pc.org> - 2012-01-23 11:42 -0800
        Re: CASE comparison values Percy <percival.andrews@gmail.com> - 2012-01-23 14:58 -0800
          Re: CASE comparison values "Elizabeth D. Rather" <erather@forth.com> - 2012-01-23 13:41 -1000
          Re: CASE comparison values Brad <hwfwguy@gmail.com> - 2012-01-23 19:20 -0800
        Re: CASE comparison values "Peter Knaggs" <pjk@bcs.org.uk> - 2012-01-24 10:03 +0000

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