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Re: C parser ramblings, language design, etc

From "Rod Pemberton" <boo@fasdfrewar.cdm>
Newsgroups alt.os.development
Subject Re: C parser ramblings, language design, etc
Date 2015-09-13 04:41 -0400
Organization Aioe.org NNTP Server
Message-ID <op.x4v7q5xkyfako5@localhost> (permalink)
References <op.x4tmp0ssyfako5@localhost> <76dff2ed-c7a8-42fe-8eab-82d1dce5487f@googlegroups.com>

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On Sat, 12 Sep 2015 08:10:23 -0400, Alexei A. Frounze <alexfrunews@gmail.com> wrote:

> On Friday, September 11, 2015 at 4:11:45 PM UTC-7, Rod Pemberton wrote:

>> no keyword for typedef
>> usage,
>
> What kind of usage?

'union' and 'struct' keywords both declare the data type and declare
variables of said type.  'typedef' only declares the data type.  So,
usage of a typedef without needing a keyword prior to it creates a
conflict between an identifier and typedef name in the grammar.  This
also creates conflicts with implicit ints.

union abc{
...
}

union abc var0;


typedef int abc;

<here> abc var1;

There is no keyword at <here>, such as 'typedef'.  That's the problem.
The grammar expects a keyword like 'union' or 'struct' there, but
there is nothing for a 'typedef'.  This problem has to be solved by
some other method: expansion of 'abc' to 'int', symbol lookup tables,
state-machine to determine "missing" typedef, etc.

BTW, I've had this conversation with both you and James,
and multiple times with James going back *many* years both
here and comp.lang.misc: 2014, '13, '11, '8 ...  There is
in-depth info, including links to discussions on the issue
by ANSI C X3J11 maintainers, in a couple of those threads.

>> 'while' is overloaded or ambiguous.
>
> Not entirely ambiguous. If you look at the language, many
> things have dual and even triple(?) use.

at least quadruple: 'static' keyword

>> It means two different
>> things at different places, and somehow the parser or compiler
>> must distinquish and keep track of which 'while' goes with
>> which 'do'.  Nesting can throw the dual-keyword do-while loop
>> tracking out of whack.  Adding nested while just complicates
>> it further.  You almost need a stack and a state-machine.
>
> You do. Yo do need a state machine and some kind of stack.

I.e., it's not simple enough for such an old language.
Maybe, "trivial" is the word I'm looking for ...

>> That would've been much simpler to parse and emit code for if a
>> different keyword was used at the bottom of the loop or if the
>> condition was placed at the top of the loop for a do-while.
>
> You could indeed use some sort of do/repeat-while() and
> do/repeat-until(). But in any case you still need to parse
> everything in between. And you are still not free to grab the
> first while/until you see and use it to close the loop. If you
> support comments and strings or string literals, you still need
> to parse while maintaining state.

A simple counter can keep track of scope level.  So, the next loop
ending keyword at the same scope level terminates the loop, if
the conflict between standalone 'while' and the 'while' of a do-while
didn't exist.

> // this while is part of a comment
> "this while is part of a string"
> // "this while is part of a comment"
> "this // while is part of a string"
>
> Or do you propose to do something radical with strings and
> comments as well so as to eliminate stateful parsing of them
> and of everything around?

An int flag for each (in comment, or in string) is sufficient.


Rod Pemberton

-- 
Just how many texting and calendar apps does humanity need?

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Thread

C parser ramblings, language design, etc "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-09-11 19:11 -0400
  Re: C parser ramblings, language design, etc "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-09-12 05:10 -0700
    Re: C parser ramblings, language design, etc "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-09-13 04:41 -0400
      Re: C parser ramblings, language design, etc "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-09-13 02:37 -0700
        Re: C parser ramblings, language design, etc "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-09-13 07:20 -0400
          Re: C parser ramblings, language design, etc "James Harris" <james.harris.1@gmail.com> - 2015-09-13 18:37 +0100
        Re: C parser ramblings, language design, etc "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-09-13 21:03 -0700
  Re: C parser ramblings, language design, etc "James Harris" <james.harris.1@gmail.com> - 2015-09-12 13:49 +0100
    Re: C parser ramblings, language design, etc "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-09-13 06:27 -0400
      Re: C parser ramblings, language design, etc "James Harris" <james.harris.1@gmail.com> - 2015-09-13 19:02 +0100
        Re: C parser ramblings, language design, etc "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-09-13 15:10 -0700
        Re: C parser ramblings, language design, etc "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-09-13 20:30 -0400
          Re: C parser ramblings, language design, etc "Alexei A. Frounze" <alexfrunews@gmail.com> - 2015-09-13 20:07 -0700
          Re: C parser ramblings, language design, etc "James Harris" <james.harris.1@gmail.com> - 2015-09-14 22:29 +0100
            Re: C parser ramblings, language design, etc "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-09-20 18:48 -0400
              Re: C parser ramblings, language design, etc "James Harris" <james.harris.1@gmail.com> - 2015-09-22 20:04 +0100
                Re: C parser ramblings, language design, etc "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-09-30 20:32 -0400
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2015-12-27 13:51 +0000
                Re: C parser ramblings, language design, etc "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-12-27 17:35 -0500
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-01-16 17:09 +0000
                Re: C parser ramblings, language design, etc Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-01-16 14:30 -0500
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-01-16 21:40 +0000
                Re: C parser ramblings, language design, etc Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-01-18 07:34 -0500
                Re: C parser ramblings, language design, etc Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-01-18 08:37 -0500
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-01-18 23:35 +0000
                Re: C parser ramblings, language design, etc "wolfgang kern" <nowhere@never.at> - 2016-01-19 12:52 +0100
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-01-19 13:09 +0000
                Re: C parser ramblings, language design, etc "wolfgang kern" <nowhere@never.at> - 2016-01-19 21:46 +0100
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-01-21 11:15 +0000
                Re: C parser ramblings, language design, etc "wolfgang kern" <nowhere@never.at> - 2016-01-21 21:48 +0100
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-01-22 15:16 +0000
                Re: C parser ramblings, language design, etc "wolfgang kern" <nowhere@never.at> - 2016-01-22 23:02 +0100
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-01-23 17:04 +0100
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-01-27 15:27 +0000
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-02-29 09:26 +0100
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-02-29 19:02 +0000
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-03-02 20:48 +0000
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-03-09 22:29 +0100
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-03-17 16:41 +0000
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-03-29 09:00 +0200
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-03-09 22:29 +0100
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-03-17 17:36 +0000
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-03-29 09:01 +0200
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-04-02 10:13 +0100
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-04-10 19:33 +0200
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-04-15 16:27 +0200
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-04-26 08:10 +0100
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-05-03 20:14 +0200
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-05-04 09:17 +0100
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-05-21 21:10 +0200
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-05-29 08:44 +0100
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-05-29 12:05 +0200
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-05-29 12:28 +0100
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-06-01 19:22 +0200
                OT: Obama in the UK (was: C parser ramblings, language design, etc) James Harris <james.harris.1@gmail.com> - 2016-04-26 08:46 +0100
                Re: OT: Obama in the UK (was: C parser ramblings, language design, etc) Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-04-26 23:58 -0400
                Re: OT: Obama in the UK (was: C parser ramblings, language design, etc) Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-04-27 00:08 -0400
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-04-27 06:40 +0100
                Re: OT: Obama in the UK Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-04-27 05:25 -0400
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-04-27 17:45 +0100
                Re: OT: Obama in the UK Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-04-27 18:25 -0400
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-05-02 23:44 +0100
                Re: OT: Obama in the UK Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-05-03 16:56 -0400
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-05-04 09:23 +0100
                Re: OT: Obama in the UK Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-05-04 17:22 -0400
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-05-06 11:47 +0100
                Re: OT: Obama in the UK Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-05-06 19:34 -0400
                Re: OT: Obama in the UK "James Harris" <james.harris.1@gmail.com> - 2016-05-07 12:51 +0100
                Re: OT: Obama in the UK Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-05-07 19:20 -0400
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-05-08 01:46 +0100
                Re: OT: Obama in the UK Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-05-07 21:43 -0400
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-05-08 09:36 +0100
                Re: OT: Obama in the UK Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-05-08 15:34 -0400
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-05-10 11:25 +0100
                Re: OT: Obama in the UK Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-05-10 17:32 -0400
                Re: OT: Obama in the UK Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-05-10 18:25 -0400
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-05-15 00:06 +0100
                Re: OT: Obama in the UK Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-05-07 21:32 -0400
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-06-02 07:41 +0100
                Re: OT: Obama in the UK Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-06-02 16:21 -0400
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-05-20 14:59 +0100
                Re: OT: Obama in the UK "wolfgang kern" <nowhere@never.at> - 2016-05-20 21:13 +0200
                Re: OT: Obama in the UK "wolfgang kern" <nowhere@never.at> - 2016-05-20 21:17 +0200
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-05-21 08:04 +0100
                Re: OT: Obama in the UK Bernhard Schornak <schornak@web.de> - 2016-05-21 21:10 +0200
                Re: OT: Obama in the UK "wolfgang kern" <nowhere@never.at> - 2016-05-21 11:16 +0200
                Re: OT: Obama in the UK Bernhard Schornak <schornak@web.de> - 2016-05-21 21:11 +0200
                Re: OT: Obama in the UK Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-05-20 22:51 -0400
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-05-21 07:29 +0100
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-06-02 08:33 +0100
                Re: OT: Obama in the UK Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-06-02 16:21 -0400
                UK pronunciation was, [Re: OT: Obama in the UK, was C lang parser ramblings] Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-06-11 14:34 -0400
                Re: UK pronunciation was, [Re: OT: Obama in the UK, was C lang parser ramblings] James Harris <james.harris.1@gmail.com> - 2016-07-24 18:28 +0100
                Re: UK pronunciation was, [Re: OT: Obama in the UK, was C lang parser ramblings] Rod Pemberton <NoHaveNotOne@bcczxcfrze.cam> - 2016-07-25 21:54 -0400
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-07-24 18:21 +0100
                Re: OT: Obama in the UK Rod Pemberton <NoHaveNotOne@bcczxcfrze.cam> - 2016-07-25 21:54 -0400
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-07-26 10:02 +0100
                Re: OT: Obama in the UK Rod Pemberton <NoHaveNotOne@bcczxcfrze.cam> - 2016-07-26 07:56 -0400
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-07-30 12:26 +0100
                Re: OT: Obama in the UK Bernhard Schornak <schornak@web.de> - 2016-05-03 20:14 +0200
                Re: OT: Obama in the UK James Harris <james.harris.1@gmail.com> - 2016-05-04 09:25 +0100
                Re: OT: Obama in the UK Bernhard Schornak <schornak@web.de> - 2016-05-21 21:11 +0200
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-04-26 07:59 +0100
                Re: C parser ramblings, language design, etc Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-04-27 00:01 -0400
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-04-27 09:28 +0100
                Re: C parser ramblings, language design, etc Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-04-27 05:42 -0400
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-04-27 17:16 +0100
                Re: C parser ramblings, language design, etc Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-04-27 18:05 -0400
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-04-27 09:29 +0100
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-04-27 09:42 +0100
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-05-03 20:14 +0200
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-05-07 14:34 +0100
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-05-21 21:10 +0200
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-05-29 11:27 +0100
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-06-01 19:22 +0200
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-05-07 16:34 +0100
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-05-21 21:10 +0200
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-05-29 12:10 +0100
                Re: C parser ramblings, language design, etc Bernhard Schornak <schornak@web.de> - 2016-06-01 19:22 +0200
                Re: C parser ramblings, language design, etc Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-01-25 18:29 -0500
                Re: C parser ramblings, language design, etc "wolfgang kern" <nowhere@never.at> - 2016-01-26 11:47 +0100
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-01-27 17:08 +0000
                Re: C parser ramblings, language design, etc "wolfgang kern" <nowhere@never.at> - 2016-01-28 11:54 +0100
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-01-28 11:47 +0000
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-01-21 10:13 +0000
                Re: C parser ramblings, language design, etc Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-01-25 18:29 -0500
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-01-27 17:15 +0000
                Re: C parser ramblings, language design, etc Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-01-27 17:31 -0500
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-01-28 11:07 +0000
                Re: C parser ramblings, language design, etc Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-01-19 22:28 -0500
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-01-22 15:04 +0000
                Re: C parser ramblings, language design, etc Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-01-25 17:48 -0500
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2016-01-27 17:16 +0000
                Re: cows and bulls game, was [Re: C parser ramblings, language design, etc] "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-12-27 21:19 -0500
              Re: C parser ramblings, language design, etc "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-09-30 20:32 -0400
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2015-10-05 15:13 +0100
                Re: C parser ramblings, language design, etc "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-10-05 21:56 -0400
                Re: C parser ramblings, language design, etc James Harris <james.harris.1@gmail.com> - 2015-12-27 13:56 +0000
                Re: C parser ramblings, language design, etc "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-10-21 19:46 -0400
  Re: C parser ramblings, language design, etc "James Harris" <james.harris.1@gmail.com> - 2015-09-12 15:38 +0100
    Re: C parser ramblings, language design, etc "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-09-13 07:10 -0400
  Re: C parser ramblings, language design, etc "s_dubrovich@yahoo.com" <s_dubrovich@yahoo.com> - 2015-11-01 09:07 -0800

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