Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.forth > #36431

Control-flow stack (was: Static Single Assignment ...)

From anton@mips.complang.tuwien.ac.at (Anton Ertl)
Newsgroups comp.lang.forth
Subject Control-flow stack (was: Static Single Assignment ...)
Date 2015-02-10 14:29 +0000
Organization Institut fuer Computersprachen, Technische Universitaet Wien
Message-ID <2015Feb10.152916@mips.complang.tuwien.ac.at> (permalink)
References <82c4c3dc-7692-4d03-a447-9bdd54ff9387@googlegroups.com> <mb8gem$ev7$1@dont-email.me> <5bbc76d4-6847-4e8d-8e55-68a4d5ffa118@googlegroups.com> <mbcshk$nri$1@dont-email.me> <54d9ff6a$0$3895$e4fe514c@dreader34.news.xs4all.nl>

Show all headers | View raw

albert@spenarnc.xs4all.nl (Albert van der Horst) writes:
>In article <mbcshk$nri$1@dont-email.me>,
>Alex McDonald <blog@rivadpm.com> wrote:
>>Where this wouldn't work is
>>
>>: foo ... [ buf-size maxbuffer - dup 1+ ] if literal else literal then
>>.. ;
>>
>>Here the control flow, if on the data stack, has pushed down the literals
>>and we can't get at them. Are you claiming this is idiomatic, with use of
>>LITERAL inside a control flow where the literal value is put on the stack
>>before it?
>>
>
>If Hugh isn't, I am. And it is a pitfall because one needs to read the
>standard very carefully to realize that : might leave something
>on the control stack.

You mean the data stack, and the case you are thinking of is not the
one Alex McDonald presented as example.  What you are thinking of is
simething like

buf-size maxbuffer - : foo literal + ;

Here Forth-94 says:

|6.1.0450 : colon CORE\
|	( C: "<spaces>name" -- colon-sys )

2.2.2 "Stack notation" explains that C: stands for the control-flow
stack, and 3.2.3.2 "Control-flow stack" explains that the control-flow
stack may be implemented using the data stack.

I don't think this needs more careful reading than other aspects of
the standard.

It seems to me that using the data stack as control-flow stack is
common practice (are there any exceptions?).  Tightening the standard
to disallow a separate control-flow stack would not give progammers a
lot of additional freedom, because all the control-flow stack items
are opaque and the number of cells they contain is not standardized;
but it would have the following effects:

* No need to document the possibility of a separate control-flow
  stack.  The standard becomes easier to understand.

* Programmers could use DEPTH to find out the size of an individual
  control-flow stack item, and then copy it, store it to memory, or
  otherwise manipulate it.  This is probably ok for many compilers,
  but other compilers might have been written with the assumption that
  only the standard control-flow stack manipulation words are used for
  dealing with control-flow stack items, and would not work with the
  programmer-written ones.  Are there such compilers?

- anton
-- 
M. Anton Ertl  http://www.complang.tuwien.ac.at/anton/home.html
comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
     New standard: http://www.forth200x.org/forth200x.html
   EuroForth 2014: http://www.euroforth.org/ef14/

Back to comp.lang.forth | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Static Single Assignment form to Stack allocation Aliaksei Chapyzhenka <alex.drom@gmail.com> - 2015-02-05 20:01 -0800
  Re: Static Single Assignment form to Stack allocation Paul Rubin <no.email@nospam.invalid> - 2015-02-05 21:00 -0800
    Re: Static Single Assignment form to Stack allocation "Rod Pemberton" <buzz@notnotnontnooatno.cmm> - 2015-02-06 02:15 -0500
      Re: Static Single Assignment form to Stack allocation Paul Rubin <no.email@nospam.invalid> - 2015-02-06 12:07 -0800
        Re: Static Single Assignment form to Stack allocation Jan Coombs <Jan-54 <jenfhaomndgfwutc@murmic.plus.com>> - 2015-02-08 22:38 +0000
          Re: Static Single Assignment form to Stack allocation Paul Rubin <no.email@nospam.invalid> - 2015-02-08 14:55 -0800
            Re: Static Single Assignment form to Stack allocation Aliaksei Chapyzhenka <alex.drom@gmail.com> - 2015-02-08 19:59 -0800
  Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-06 13:15 +0000
  Re: Static Single Assignment form to Stack allocation anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-02-06 13:22 +0000
    Re: Static Single Assignment form to Stack allocation Aliaksei Chapyzhenka <alex.drom@gmail.com> - 2015-02-06 11:16 -0800
      Re: Static Single Assignment form to Stack allocation Paul Rubin <no.email@nospam.invalid> - 2015-02-06 12:05 -0800
      Re: Static Single Assignment form to Stack allocation hughaguilar96@gmail.com - 2015-02-06 16:44 -0800
        Re: Static Single Assignment form to Stack allocation "Rod Pemberton" <buzz@notnotnontnooatno.cmm> - 2015-02-06 23:41 -0500
      Re: Static Single Assignment form to Stack allocation "Rod Pemberton" <buzz@notnotnontnooatno.cmm> - 2015-02-06 23:41 -0500
        Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-07 19:22 +0000
          Re: Static Single Assignment form to Stack allocation Aliaksei Chapyzhenka <alex.drom@gmail.com> - 2015-02-07 13:09 -0800
            Re: Static Single Assignment form to Stack allocation "Elizabeth D. Rather" <erather@forth.com> - 2015-02-07 11:25 -1000
              Re: Static Single Assignment form to Stack allocation Aliaksei Chapyzhenka <alex.drom@gmail.com> - 2015-02-07 14:09 -0800
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-07 22:32 +0000
                Re: Static Single Assignment form to Stack allocation Aliaksei Chapyzhenka <alex.drom@gmail.com> - 2015-02-07 14:51 -0800
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-08 00:04 +0000
                Re: Static Single Assignment form to Stack allocation Aliaksei Chapyzhenka <alex.drom@gmail.com> - 2015-02-07 17:03 -0800
                Re: Static Single Assignment form to Stack allocation "Rod Pemberton" <buzz@notnotnontnooatno.cmm> - 2015-02-07 21:04 -0500
                Re: Static Single Assignment form to Stack allocation "Rod Pemberton" <buzz@notnotnontnooatno.cmm> - 2015-02-07 21:10 -0500
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-08 10:57 +0000
                Re: Static Single Assignment form to Stack allocation "Rod Pemberton" <buzz@notnotnontnooatno.cmm> - 2015-02-07 21:05 -0500
            Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-07 22:24 +0000
          Re: Static Single Assignment form to Stack allocation "Elizabeth D. Rather" <erather@forth.com> - 2015-02-07 11:21 -1000
          Re: Static Single Assignment form to Stack allocation "Rod Pemberton" <buzz@notnotnontnooatno.cmm> - 2015-02-07 20:11 -0500
            Re: Static Single Assignment form to Stack allocation "Elizabeth D. Rather" <erather@forth.com> - 2015-02-07 15:35 -1000
              Re: Static Single Assignment form to Stack allocation "Elizabeth D. Rather" <erather@forth.com> - 2015-02-07 16:52 -1000
                Re: Static Single Assignment form to Stack allocation hughaguilar96@gmail.com - 2015-02-08 10:21 -0800
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-08 20:09 +0000
                Re: Static Single Assignment form to Stack allocation "Elizabeth D. Rather" <erather@forth.com> - 2015-02-08 17:15 -1000
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-09 12:00 +0000
                Re: Static Single Assignment form to Stack allocation albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-02-09 13:05 +0000
                Re: Static Single Assignment form to Stack allocation "HAA" <someone@microsoft.com> - 2015-02-10 16:01 +1100
                Re: Static Single Assignment form to Stack allocation "Rod Pemberton" <buzz@notnotnontnooatno.cmm> - 2015-02-09 02:35 -0500
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-09 12:03 +0000
              Re: Static Single Assignment form to Stack allocation hughaguilar96@gmail.com - 2015-02-08 10:13 -0800
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-08 20:21 +0000
                Re: Static Single Assignment form to Stack allocation hughaguilar96@gmail.com - 2015-02-09 22:49 -0800
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-10 12:12 +0000
                Re: Static Single Assignment form to Stack allocation albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-02-10 12:54 +0000
                Re: Static Single Assignment form to Stack allocation Mark Wills <markwills1970@gmail.com> - 2015-02-10 06:30 -0800
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-10 14:53 +0000
                Re: Static Single Assignment form to Stack allocation "Elizabeth D. Rather" <erather@forth.com> - 2015-02-10 08:20 -1000
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-10 14:33 +0000
                Re: Static Single Assignment form to Stack allocation albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-02-10 19:09 +0000
                Control-flow stack (was: Static Single Assignment ...) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-02-10 14:29 +0000
                Re: Control-flow stack (was: Static Single Assignment ...) "Alex McDonald" <blog@rivadpm.com> - 2015-02-10 15:49 +0000
                Re: Control-flow stack (was: Static Single Assignment ...) albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-02-10 17:56 +0000
                Re: Control-flow stack (was: Static Single Assignment ...) "Alex McDonald" <blog@rivadpm.com> - 2015-02-10 20:53 +0000
                Re: Control-flow stack "Elizabeth D. Rather" <erather@forth.com> - 2015-02-10 13:08 -1000
                Re: Control-flow stack awegel@arcor.de (Alexander Wegel) - 2015-02-11 03:15 +0100
                Re: Control-flow stack hughaguilar96@gmail.com - 2015-02-10 18:47 -0800
                Re: Control-flow stack Unknown <dog@gmail.com> - 2015-02-17 07:13 +0000
                Re: Control-flow stack anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-02-11 17:59 +0000
                Re: Control-flow stack (was: Static Single Assignment ...) Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-02-11 01:30 -0800
                Re: Control-flow stack (was: Static Single Assignment ...) "Rod Pemberton" <buzz@notnotnontnooatno.cmm> - 2015-02-10 18:43 -0500
                Re: Control-flow stack (was: Static Single Assignment ...) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-02-11 17:46 +0000
                Re: Control-flow stack (was: Static Single Assignment ...) "Alex McDonald" <blog@rivadpm.com> - 2015-02-11 22:39 +0000
                Re: Control-flow stack (was: Static Single Assignment ...) "Alex McDonald" <blog@rivadpm.com> - 2015-02-11 22:42 +0000
                Re: Control-flow stack (was: Static Single Assignment ...) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-02-12 09:52 +0000
                Re: Control-flow stack (was: Static Single Assignment ...) "Alex McDonald" <blog@rivadpm.com> - 2015-02-12 10:28 +0000
                Re: Control-flow stack (was: Static Single Assignment ...) hughaguilar96@gmail.com - 2015-02-11 20:23 -0800
                Re: Control-flow stack (was: Static Single Assignment ...) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-02-12 07:21 +0000
                Re: Control-flow stack (was: Static Single Assignment ...) hughaguilar96@gmail.com - 2015-02-12 18:33 -0800
                Re: Control-flow stack awegel@arcor.de (Alexander Wegel) - 2015-02-13 04:46 +0100
                Re: Control-flow stack "Rod Pemberton" <buzz@notnotnontnooatno.cmm> - 2015-02-13 06:48 -0500
                Re: Control-flow stack awegel@arcor.de (Alexander Wegel) - 2015-02-13 13:40 +0100
                Re: Control-flow stack albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-02-13 15:49 +0000
                Re: Control-flow stack awegel@arcor.de (Alexander Wegel) - 2015-02-14 03:47 +0100
                Re: Control-flow stack anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-02-13 16:09 +0000
                Re: Control-flow stack (was: Static Single Assignment ...) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-02-13 15:20 +0000
                Re: Control-flow stack (was: Static Single Assignment ...) hughaguilar96@gmail.com - 2015-02-13 21:31 -0800
                Re: Control-flow stack awegel@arcor.de (Alexander Wegel) - 2015-02-14 03:47 +0100
                Re: Control-flow stack (was: Static Single Assignment ...) hughaguilar96@gmail.com - 2015-02-14 19:22 -0800
                Re: Control-flow stack (was: Static Single Assignment ...) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-02-15 11:09 +0000
                Re: Control-flow stack (was: Static Single Assignment ...) hughaguilar96@gmail.com - 2015-02-15 16:57 -0800
                Re: Control-flow stack (was: Static Single Assignment ...) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-02-16 14:41 +0000
                Re: Control-flow stack (was: Static Single Assignment ...) hughaguilar96@gmail.com - 2015-02-16 18:43 -0800
                Re: Control-flow stack Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-02-10 22:04 +0000
                Re: Control-flow stack Harold <hzrabbie@gmail.com> - 2015-02-10 16:58 -0800
                Re: Control-flow stack Bernd Paysan <bernd.paysan@gmx.de> - 2015-02-11 02:51 +0100
                Re: Control-flow stack albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-02-11 11:34 +0000
                Re: Control-flow stack Harold <hzrabbie@gmail.com> - 2015-02-11 08:17 -0800
                Re: Control-flow stack "Elizabeth D. Rather" <erather@forth.com> - 2015-02-10 16:37 -1000
                Re: Control-flow stack hughaguilar96@gmail.com - 2015-02-10 18:57 -0800
                Re: Static Single Assignment form to Stack allocation "Rod Pemberton" <buzz@notnotnontnooatno.cmm> - 2015-02-10 18:44 -0500
                Re: Static Single Assignment form to Stack allocation "Elizabeth D. Rather" <erather@forth.com> - 2015-02-10 14:49 -1000
                Re: Static Single Assignment form to Stack allocation hughaguilar96@gmail.com - 2015-02-10 18:16 -0800
                Re: Static Single Assignment form to Stack allocation Mark Wills <markwills1970@gmail.com> - 2015-02-11 00:35 -0800
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-11 09:35 +0000
                Re: Static Single Assignment form to Stack allocation Mark Wills <markwills1970@gmail.com> - 2015-02-11 03:06 -0800
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-11 14:27 +0000
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-11 14:40 +0000
                Re: Static Single Assignment form to Stack allocation "Rod Pemberton" <buzz@notnotnontnooatno.cmm> - 2015-02-12 20:02 -0500
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-13 11:42 +0000
                Re: Static Single Assignment form to Stack allocation "Rod Pemberton" <buzz@notnotnontnooatno.cmm> - 2015-02-13 07:44 -0500
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-13 14:20 +0000
                Re: Static Single Assignment form to Stack allocation "Elizabeth D. Rather" <erather@forth.com> - 2015-02-13 10:32 -1000
                Re: Static Single Assignment form to Stack allocation "Rod Pemberton" <bork@lllljunkqwer.cpm> - 2015-03-29 16:27 -0400
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-03-29 22:46 +0100
                Re: Static Single Assignment form to Stack allocation "Elizabeth D. Rather" <erather@forth.com> - 2015-03-29 15:24 -1000
                Re: Static Single Assignment form to Stack allocation hughaguilar96@gmail.com - 2015-03-30 04:44 -0700
                Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-03-30 15:33 +0100
                Re: Static Single Assignment form to Stack allocation anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-02-11 18:03 +0000
                Re: Static Single Assignment form to Stack allocation Bernd Paysan <bernd.paysan@gmx.de> - 2015-02-12 00:16 +0100
                Re: Static Single Assignment form to Stack allocation anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-02-12 07:08 +0000
            Re: Static Single Assignment form to Stack allocation "Alex McDonald" <blog@rivadpm.com> - 2015-02-08 10:51 +0000

csiph-web