Re: Formatting of Language LRMs

From	Ivan Godard <ivan@ootbcomp.com>
Newsgroups	comp.compilers
Subject	Re: Formatting of Language LRMs
Date	2014-06-20 12:09 -0700
Organization	A noiseless patient Spider
Message-ID	<14-06-016@comp.compilers> (permalink)
References	<14-06-010@comp.compilers>

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On 6/17/2014 4:24 AM, Seima Rao wrote:
>     Some of the noticeable aspect about standards is that most of them
>     tend to follow the same format: grammar in BNF, semantics in
>     documentation. This is the pattern throughout.
>
>     Therefore I am curious to know if there are other interesting formatting
>     of language standards or language definitions such that the
>     pattern is different? ...

> [People have tried lots of other definition schemes over the years, like railroad
> diagrams in some Fortran standards and VDL in PL/I.  BNF+text seems to be a workable
> balance between formalisms and readability. The PL/I standard was notably opaque,
> and its authors said "you don't have to understand it, just implement it" to which
> the answer was "yeah, bugs and all." -John]

Two very important cases not following this practice: Algol68, which
used van Wijngaarten notation ("VWG"), and Ada where the standard is
defined by a test suite. There are Ada manuals, but if the manual
differs from the suite then the suite governs.

VWG is vastly superior to BNF because it provides a formal specification
of semantics, in particular the type system, which cannot be expressed
in BNF. Unfortunately formal reasoning about semantics is beyond many
users. Stll IMO no other formal semantic notation (Denotational
Semantics for example) is superior to VWG.

The Ada approach was driven by the government procurement process in
which they had too much experience with ambiguous specification and
differing, incompatible implementations,. They sought a mechanism by
which they could have some confidence that their programs would
actually work with the same results in different environments, with
enforceable contracts that did not depend on the pissing contests of
language lawyers. This was largely successful, and Ada has a huge
canonical test suite. Other languages have evolved similar suites, and
in practice the major compilers run all their issues through each
others' compilers to produce an informal consensus, but that's not a
formal process.

Thread

Formatting of Language LRMs Seima Rao <seimarao@gmail.com> - 2014-06-17 16:54 +0530
  Re: Formatting of Language LRMs "lpsantil@gmail.com" <lpsantil@gmail.com> - 2014-06-20 10:10 -0700
    Re: Formatting of Language LRMs glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-08-03 04:37 +0000
  Re: Formatting of Language LRMs Ivan Godard <ivan@ootbcomp.com> - 2014-06-20 12:09 -0700
    Re: Formatting of Language LRMs glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-06-21 02:27 +0000
    Re: Formatting of Language LRMs Kaz Kylheku <kaz@kylheku.com> - 2014-06-21 03:09 +0000
    Re: Formatting of Language LRMs Joshua Cranmer 🐧 <Pidgeot18@verizon.net.invalid> - 2014-06-22 21:12 -0500
      Re: VWG and K, was Formatting of Language LRMs Ivan Godard <ivan@ootbcomp.com> - 2014-06-22 21:47 -0700
      RE: Formatting of Language LRMs "Costello, Roger L." <costello@mitre.org> - 2014-07-03 09:06 +0000
        Re: Formatting of Language LRMs Ivan Godard <ivan@ootbcomp.com> - 2014-07-03 22:30 -0700
          Re: syntax checkers, was Formatting of Language LRMs glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-07-04 17:35 +0000
          Re: executable semantics, was Formatting of Language LRMs wclodius@earthlink.net (William Clodius) - 2014-07-04 15:53 -0600
  Re: specifying semantics, was Formatting of Language LRMs seimarao@gmail.com - 2014-06-24 02:19 -0700
    Re: specifying semantics, was Formatting of Language LRMs "lpsantil@gmail.com" <lpsantil@gmail.com> - 2014-06-24 13:12 -0700
    Re: specifying semantics, was Formatting of Language LRMs George Neuner <gneuner2@comcast.net> - 2014-06-26 00:54 -0400
      Re: specifying semantics, was Formatting of Language LRMs Andy Walker <news@cuboid.co.uk> - 2014-06-28 20:10 +0100
        Re: specifying semantics, was Formatting of Language LRMs George Neuner <gneuner2@comcast.net> - 2014-06-28 22:43 -0400
          Re: BNF, was specifying semantics wclodius@earthlink.net (William Clodius) - 2014-06-30 22:00 -0600
      Re: specifying semantics, was Formatting of Language LRMs Ivan Godard <ivan@ootbcomp.com> - 2014-06-28 12:25 -0700
        Re: specifying semantics, was Formatting of Language LRMs Andy Walker <news@cuboid.co.uk> - 2014-06-29 11:19 +0100
        Re: specifying semantics, was Formatting of Language LRMs George Neuner <gneuner2@comcast.net> - 2014-06-29 07:56 -0400
          Re: specifying semantics, was Formatting of Language LRMs Ivan Godard <ivan@ootbcomp.com> - 2014-06-29 11:49 -0700
            Re: specifying semantics, was Formatting of Language LRMs Gene Wirchenko <genew@telus.net> - 2014-06-30 18:09 -0700
              Re: specifying semantics, was Formatting of Language LRMs Ivan Godard <ivan@ootbcomp.com> - 2014-06-30 20:53 -0700
                Re: Algol history, was specifying semantics anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-03 11:51 +0000
                Re: Algol history, was specifying semantics Ivan Godard <ivan@ootbcomp.com> - 2014-07-03 22:20 -0700
                Re: Algol history, was specifying semantics wclodius@earthlink.net (William Clodius) - 2014-07-04 15:52 -0600
                Re: Algol history, was specifying semantics glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-07-07 05:49 +0000
                Re: Algol history, was specifying semantics Ivan Godard <ivan@ootbcomp.com> - 2014-07-07 10:48 -0700
                Re: Algol history, was specifying semantics glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-07-07 19:49 +0000
                Re: Algol history, was specifying semantics glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-07-07 19:43 +0000
                Re: specifying semantics, was Formatting of Language LRMs Gene Wirchenko <genew@telus.net> - 2014-07-03 21:44 -0700
            Re: specifying semantics, was Formatting of Language LRMs anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-02 09:51 +0000
              Re: specifying semantics, was Formatting of Language LRMs Stefan Monnier <monnier@iro.umontreal.ca> - 2014-07-03 10:15 -0400
                Re: specifying semantics, was Formatting of Language LRMs glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-07-04 06:08 +0000
                Re: specifying semantics, was Formatting of Language LRMs Hans-Peter Diettrich <DrDiettrich1@aol.com> - 2014-07-04 08:51 +0200
                Re: Parsing Fortran, was specifying semantics glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-07-04 17:53 +0000
                Re: Parsing Fortran, was specifying semantics wclodius@earthlink.net (William Clodius) - 2014-07-04 15:57 -0600
  Re: Formatting of Language LRMs mertesthomas@gmail.com - 2014-06-30 12:04 -0700
  Re: Formatting of Language LRMs federation2005@netzero.com - 2014-07-28 17:55 -0700
    Re: Formatting of Language LRMs federation2005@netzero.com - 2014-08-01 14:58 -0700

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