Re: Parsers for extensible grammars?

From	Paul E Bennett <Paul_E.Bennett@topmail.co.uk>
Newsgroups	comp.arch.embedded
Subject	Re: Parsers for extensible grammars?
Date	2014-10-26 01:29 +0100
Organization	Hidecs Consultancy
Message-ID	<cb2tjjFcqd1U1@mid.individual.net> (permalink)
References	<m28vlb$lum$1@speranza.aioe.org> <cauih2F8i6eU1@mid.individual.net> <m2gn14$lpv$1@dont-email.me>

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rickman wrote:

> On 10/24/2014 4:56 AM, Paul E Bennett wrote:
>> Don Y wrote:
>>
>>> Hi,
>>>
>>> [I probably should direct this at George...  :> ]
>>>
>>> I'm writing a command parser.  Some set of commands are "common".
>>> But, other instances of the parser are augmented with additional
>>> commands/syntax.
>>>
>>> [These additions are known at compile time, not "dynamic"]
>>>
>>> Ideally, I want a solution that allows folks developing those
>>> "other" commands to just "bolt onto" what I have done.  E.g.,
>>> creating a single "grammar definition" (lex/yacc) is probably
>>> not a good way to go (IME, most small parsers tend to be ad hoc).
>>>
>>> [Note:  I can't even guarantee that the extensions will be
>>> consistent or "harmonious" with the grammar that I implement]
>>>
>>> A naive approach (?) might be for my code to take a crack at
>>> a particular "statement"/command and, in case of FAIL, invoke
>>> some bolt-on parser to give it a chance to make sense out of
>>> the input.  If *it* FAILs, then the input is invalid, etc.
>>>
>>> This sounds like an incredible kluge.  Any better suggestions?
>>
>> Hi Don,
>>
>> Have you looked at Forth? What you are describing sounds like the problem
>> that Forth solved back in 1968. It is the sort of thing that Forth
>> programmers have been doing for nearly 50 years and it works very
>> successfully for us.
>>
>> See <http://www.mpeforth.com/> and <http://www.forth.com/>
> 
> Don is a hard person to suggest things to.  I'm actually surprised that
> his response was as positive as it was.
> 
> I have had great success at solving many problems with Forth.  There are
> text file formats can be read by treating various words as commands,
> defining those words in Forth to execute while reading the file and
> storing the numeric data where it needs to be stored.  Easy peasy.  Not
> quite the same thing as what Don is likely doing, but very similar.
> 
> Don may be looking for something that will let him check the input for
> the correct syntax, number of values, etc.  But as usual he has not
> really defined the problem he is trying to solve.
 
I don't know if Don has tried playing with Forth or not, I just made a 
suggestion that what he was seeking to do sounded somewhat Forth-like in 
nature. With somewhat more difficulty he could probably look at re-creating 
a MSDOS type environment which would also suit the bill (new commands in 
batch files etc or added programmes in the COMMAND directory).

You are probably right about a lack of Clear, Concise, Correct, Coherent, 
Complete & Confirmable (Testable) specification of the requirements.

-- 
********************************************************************
Paul E. Bennett IEng MIET.....<email://Paul_E.Bennett@topmail.co.uk>
Forth based HIDECS Consultancy.............<http://www.hidecs.co.uk>
Mob: +44 (0)7811-639972
Tel: +44 (0)1235-510979
Going Forth Safely ..... EBA. www.electric-boat-association.org.uk..
********************************************************************

Thread

Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-22 12:14 -0700
  Re: Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-22 12:17 -0700
  Re: Parsers for extensible grammars? Tim Wescott <seemywebsite@myfooter.really> - 2014-10-22 15:13 -0500
    Re: Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-22 22:54 -0700
      Re: Parsers for extensible grammars? Stefan Reuther <stefan.news@arcor.de> - 2014-10-23 18:36 +0200
        Re: Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-23 12:10 -0700
      Re: Parsers for extensible grammars? Tim Wescott <seemywebsite@myfooter.really> - 2014-10-23 13:45 -0500
        Re: Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-23 12:15 -0700
      Re: Parsers for extensible grammars? jim.brakefield@ieee.org - 2014-10-24 07:05 -0700
        Re: Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-24 08:04 -0700
  Re: Parsers for extensible grammars? Clifford Heath <no.spam@please.net> - 2014-10-23 08:22 +1100
    Re: Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-22 23:25 -0700
    Re: Parsers for extensible grammars? George Neuner <gneuner2@comcast.net> - 2014-10-23 04:45 -0400
      Re: Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-23 04:14 -0700
        Re: Parsers for extensible grammars? George Neuner <gneuner2@comcast.net> - 2014-10-23 16:49 -0400
          Re: Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-24 07:38 -0700
            Re: Parsers for extensible grammars? George Neuner <gneuner2@comcast.net> - 2014-10-26 03:47 -0400
              Re: Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-26 08:41 -0700
                Re: Parsers for extensible grammars? George Neuner <gneuner2@comcast.net> - 2014-10-26 14:36 -0400
                Re: Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-26 12:37 -0700
                Re: Parsers for extensible grammars? George Neuner <gneuner2@comcast.net> - 2014-10-26 18:54 -0400
        Re: Parsers for extensible grammars? Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP> - 2014-10-25 02:02 +0000
          Re: Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-25 01:56 -0700
            Re: Parsers for extensible grammars? Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP> - 2014-10-25 11:15 +0000
              Re: Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-25 10:21 -0700
                Re: Parsers for extensible grammars? Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP> - 2014-10-26 01:05 +0000
                Re: Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-25 19:37 -0700
  Re: Parsers for extensible grammars? Andrew Smallshaw <andrews@sdf.lonestar.org> - 2014-10-23 20:04 +0000
  Re: Parsers for extensible grammars? Les Cargill <lcargill99@comcast.com> - 2014-10-23 22:30 -0500
    Re: Parsers for extensible grammars? rickman <gnuarm@gmail.com> - 2014-10-25 13:36 -0400
      Re: Parsers for extensible grammars? Les Cargill <lcargill99@comcast.com> - 2014-10-25 13:14 -0500
        Re: Parsers for extensible grammars? rickman <gnuarm@gmail.com> - 2014-10-25 14:23 -0400
          Re: Parsers for extensible grammars? Les Cargill <lcargill99@comcast.com> - 2014-10-26 00:50 -0500
          Re: Parsers for extensible grammars? albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-10-26 19:21 +0000
            Re: Parsers for extensible grammars? rickman <gnuarm@gmail.com> - 2014-10-26 15:29 -0400
  Re: Parsers for extensible grammars? Paul E Bennett <Paul_E.Bennett@topmail.co.uk> - 2014-10-24 09:56 +0100
    Re: Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-24 07:46 -0700
      Re: Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-25 19:54 -0700
        Re: Parsers for extensible grammars? Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP> - 2014-10-26 12:15 +0000
          Re: Parsers for extensible grammars? Don Y <this@is.not.me.com> - 2014-10-26 09:02 -0700
            Re: Parsers for extensible grammars? rickman <gnuarm@gmail.com> - 2014-10-26 12:13 -0400
    Re: Parsers for extensible grammars? rickman <gnuarm@gmail.com> - 2014-10-25 13:35 -0400
      Re: Parsers for extensible grammars? Paul E Bennett <Paul_E.Bennett@topmail.co.uk> - 2014-10-26 01:29 +0100
        Re: Parsers for extensible grammars? rickman <gnuarm@gmail.com> - 2014-10-25 21:11 -0400

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