Re: syntax complexity

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From	George Neuner <gneuner2@comcast.net>
Newsgroups	comp.compilers
Subject	Re: syntax complexity
Date	Mon, 20 Feb 2023 13:49:19 -0500
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On Mon, 20 Feb 2023 15:09:18 +0000, Roger L Costello
<costello@mitre.org> wrote:

>Hello Compiler Experts!
>
>Scenario: you have a language that has a BNF. You write a statement in
>the language. It is a relatively simple, basic statement. The
>statement conforms to the BNF. To show its conformance, you write the
>derivation of the statement. Surprisingly, deriving the statement
>takes many, many rules. Does that signify that the language's syntax
>is too complex?
>
>/Roger

Not necessarily.

What makes a language complicated (not "complex") is ambiguity, not
the number of grammar rules needed to recognize some particular
expression.

If you are restricted to BNF ... i.e. your tool does not allow
specifying precedence ... then recognizing even relatively simple
arithmetic expressions can (perhaps recursively) involve several
rules.

George

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syntax complexity gah4 <gah4@u.washington.edu> - 2023-02-15 15:08 -0800
  Re: syntax complexity Thomas Koenig <tkoenig@netcologne.de> - 2023-02-16 06:32 +0000
  Re: syntax complexity Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2023-02-16 12:03 +0100
    Re: syntax complexity gah4 <gah4@u.washington.edu> - 2023-02-16 11:33 -0800
      Re: syntax complexity gah4 <gah4@u.washington.edu> - 2023-02-16 16:08 -0800
      Re: syntax complexity Roger L Costello <costello@mitre.org> - 2023-02-20 15:09 +0000
        Re: syntax complexity gah4 <gah4@u.washington.edu> - 2023-02-20 09:57 -0800
          Re: syntax complexity anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2023-02-21 08:14 +0000
            Re: syntax complexity anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2023-02-21 18:39 +0000
              Re: ireegular expressions, syntax complexity anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2023-02-22 10:55 +0000
            Re: irregular expressions, syntax complexity arnold@freefriends.org (Aharon Robbins) - 2023-02-22 08:53 +0000
            Re: irregular expressions, syntax complexity Kaz Kylheku <864-117-4973@kylheku.com> - 2023-02-23 00:34 +0000
        Re: syntax complexity George Neuner <gneuner2@comcast.net> - 2023-02-20 13:49 -0500
      syntax complexity Christopher F Clark <christopher.f.clark@compiler-resources.com> - 2023-02-21 20:54 +0200

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