precedence have both ways

From	jgk@panix.com (Joe keane)
Newsgroups	comp.compilers
Subject	precedence have both ways
Date	2013-05-30 23:21 -0400
Organization	Public Access Networks Corp.
Message-ID	<13-05-020@comp.compilers> (permalink)
References	<13-05-010@comp.compilers> <13-05-018@comp.compilers>

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Anton Ertl <anton@mips.complang.tuwien.ac.at> wrote:
>a<3 AND b<3

This reminds me of a question.

One person designs a language 'C1' with precedence:

    [higher]
    ...
    |
    &
    <, <=, >, <=
    ==, !=
    ...
    [lower]

Some other person designs a language 'C2' with precedence:

    [higher]
    ...
    <, <=, >, <=
    ==, !=
    |
    &
    ...
    [lower]

They're the same besides that.

To compromise, they make a new language 'C3' such that a program is
valid C3 if it is valid C1 and valid C2 -and- both ways mean the same.

Is there some good way to do this -in the grammar-?

[I see gcc has warnings like this.]

Thread

Articles/books that discuss separating the context-free part of a language from the context-sensitive part? "Costello, Roger L." <costello@mitre.org> - 2013-05-17 20:57 +0000
  Re: Articles/books that discuss separating the context-free part of a language from the context-sensitive part? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-05-18 00:18 +0000
    Re: Articles/books that discuss separating the context-free part of a language from the context-sensitive part? Gene Wirchenko <genew@telus.net> - 2013-05-19 18:02 -0700
      Re: Articles/books that discuss separating the context-free part of a language from the context-sensitive part? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-05-20 03:17 +0000
  Re: Articles/books that discuss separating the context-free part of a language from the context-sensitive part? Aleksey Demakov <ademakov@gmail.com> - 2013-05-18 16:52 +0400
  Re: Articles/books that discuss separating the context-free part of a language from the context-sensitive part? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-05-20 10:53 +0000
    Re: Articles/books that discuss separating the context-free part of a language from the context-sensitive part? Gene Wirchenko <genew@telus.net> - 2013-05-20 23:24 -0700
    precedence have both ways jgk@panix.com (Joe keane) - 2013-05-30 23:21 -0400
      Re: precedence have both ways glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2013-05-31 05:10 +0000
      Re: precedence have both ways anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-05-31 10:54 +0000

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