Re: Supporting multiple input syntaxes

From	antispam@math.uni.wroc.pl
Newsgroups	comp.compilers
Subject	Re: Supporting multiple input syntaxes
Date	2021-02-23 23:28 +0000
Organization	Politechnika Wroclawska
Message-ID	<21-02-008@comp.compilers> (permalink)
References	<20-08-002@comp.compilers> <21-02-004@comp.compilers> <21-02-005@comp.compilers>

Show all headers | View raw

Elijah Stone <elronnd@elronnd.net> wrote:
> On Thu, 11 Feb 2021, antispam@math.uni.wroc.pl wrote:
>
> > My impression is that variation in Pascal dialects is larger than in C
> > dialects, so case for unified parser in C IMHO
>
> Pascal is more fragmented, but it's also much easier to parse than C.  I
> think it's a wash.

I did a C parser, it was not hard at all.  I in C (like in standard
Pascal) there are conflicts, but that conflicts can be resolved
easily using semantic info.  Alternativly, for C one can use 2
token lookahead.  Turbo Pascal folks introduced "interesting"
difficulty with caret constants.  Frank Heckenbach worked out
how to handle them and his analysis indicates that correct
handling of Turbo Pascal needs IIRC 6 tokens of lookahead.

Note that for both Pascal and C, with 1 token of lokahead
semantic info is available when needed to disambiguate
parsing, once you have more than 1 token of lokahead
semantic info is sometimes too late and in effect paser
must work purely syntactically.

> (I also think the whole idea is horrifying and ought not to be pursued;
> but.)

What you mean by "whole idea"?  Do you think that creating
compiler that can correctly handle multiple dialects (Pascal
or other language) is wrong?

--
                              Waldek Hebisch

Back to comp.compilers | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

Supporting multiple input syntaxes luser droog <mijoryx@yahoo.com.dmarc.email> - 2020-08-12 15:20 -0700
  Re: Supporting multiple input syntaxes Kaz Kylheku <793-849-0957@kylheku.com> - 2020-08-13 00:43 +0000
  Re: Supporting multiple input syntaxes Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2020-08-13 10:27 +0200
    Re: Supporting multiple input syntaxes luser droog <mijoryx@yahoo.com.dmarc.email> - 2020-08-13 21:36 -0700
    Re: Supporting multiple input syntaxes luser droog <mijoryx@yahoo.com.dmarc.email> - 2020-08-23 22:16 -0700
  Re: Supporting multiple input syntaxes minforth@arcor.de - 2020-08-13 14:15 -0700
    Re: Supporting multiple input syntaxes luser droog <mijoryx@yahoo.com.dmarc.email> - 2020-08-13 21:37 -0700
    RE: Supporting mulitple input syntaxes Christopher F Clark <christopher.f.clark@compiler-resources.com> - 2020-08-14 12:44 +0300
  Supporting multiple input syntaxes David Lovemore <davidlovemore@gmail.com> - 2020-08-15 06:42 -0700
    Re: Supporting multiple input syntaxes luser droog <mijoryx@yahoo.com.dmarc.email> - 2020-08-15 15:20 -0700
      Re: Supporting multiple input syntaxes David Lovemore <davidlovemore@gmail.com> - 2020-08-16 02:21 -0700
        Re: Supporting multiple input syntaxes luser droog <mijoryx@yahoo.com.dmarc.email> - 2020-08-20 14:45 -0700
          Re: Supporting multiple input syntaxes luser droog <mijoryx@yahoo.com.dmarc.email> - 2020-08-23 19:35 -0700
            Re: implementation languages, was Supporting multiple input syntaxes luser droog <mijoryx@yahoo.com.dmarc.email> - 2020-08-23 20:39 -0700
              Re: implementation languages, was Supporting multiple input syntaxes Thomas Koenig <tkoenig@netcologne.de> - 2020-08-24 17:01 +0000
                Re: implementation languages, was Supporting multiple input syntaxes luser droog <mijoryx@yahoo.com.dmarc.email> - 2020-08-28 10:56 -0700
              Re: stack languages, was Supporting multiple input syntaxes luser droog <mijoryx@yahoo.com.dmarc.email> - 2020-08-24 12:14 -0700
  Re: Supporting multiple input syntaxes gah4 <gah4@u.washington.edu> - 2020-08-23 14:26 -0700
  Re: Supporting multiple input syntaxes antispam@math.uni.wroc.pl - 2021-02-11 23:27 +0000
    Re: Supporting multiple input syntaxes Elijah Stone <elronnd@elronnd.net> - 2021-02-17 01:44 -0800
      Re: Supporting multiple input syntaxes antispam@math.uni.wroc.pl - 2021-02-23 23:28 +0000
        Re: Supporting multiple input syntaxes "ltc...@gmail.com" <ltcmelo@gmail.com> - 2021-03-14 21:08 -0400
  Re: Supporting multiple input syntaxes Rock Brentwood <rockbrentwood@gmail.com> - 2021-03-14 17:36 -0700

csiph-web