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Re: continue equivalent in Forth?

From anton@mips.complang.tuwien.ac.at (Anton Ertl)
Newsgroups comp.lang.forth
Subject Re: continue equivalent in Forth?
Date 2012-08-28 15:56 +0000
Organization Institut fuer Computersprachen, Technische Universitaet Wien
Message-ID <2012Aug28.175604@mips.complang.tuwien.ac.at> (permalink)
References <k1gaca$vu1$1@dont-email.me> <56581508958435@frunobulax.edu>

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mhx@iae.nl (Marcel Hendrix) writes:
>Why don't other Forths have SECURE?

What does SECURE do?  Why should we have it?

>: test begin 1 2 + else 3 then ;  ok
...
>(gForth can't be caught that easily.)

: test begin 1 2 + else 3 then ; 
:1: expected orig 
: test begin 1 2 + >>>else<<< 3 then ;

So Gforth usually notices when it does not get an orig, but something
else, and likewise it will complain if you pass it an orig while it
expects a dest.  And every Forth-94 system is allowed to do this kind
of checking, as well as checking for unbalanced control flow stack,
e.g.:

: foo if ; 
:2: unstructured 
: foo if >>>;<<<

What does SECURE add? Is it worth the price of not being able to run
standard programs like Josh Grams implementation of CASE etc.?

>Another reason for iForth's SECURE is that the compiler uses 
>extra items on the CS stack to remember when registers should 
>be spilled/loaded to/from the stacks for control flow nodes. 

Gforth uses larger CS items to remember which locals are alive at a
branch (orig) or branch target (dest); can be done nicely in a
Forth-94 compatible way, and I guess that's also true for your
register information.  What do you do if SECURE is OFF?

>These extra CS items can be used to give better messages, but as 
>that is not ANS compatible, there must be a way to turn them off.

Yes the error messages of Gforth could be better, e.g., the first one
could be "control structure mismatch, expected orig".

- 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 2012: http://www.euroforth.org/ef12/

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continue equivalent in Forth? programmingkidx@gmail.com - 2012-08-18 19:28 -0700
  Re: continue equivalent in Forth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-08-19 01:43 -0500
  Re: continue equivalent in Forth? mhx@iae.nl - 2012-08-19 03:40 -0700
  Re: continue equivalent in Forth? "Ed" <invalid@nospam.com> - 2012-08-19 21:07 +1000
    Re: continue equivalent in Forth? Coos Haak <chforth@hccnet.nl> - 2012-08-19 13:55 +0200
      Re: continue equivalent in Forth? "Ed" <invalid@nospam.com> - 2012-08-20 22:13 +1000
    Re: continue equivalent in Forth? Coos Haak <chforth@hccnet.nl> - 2012-08-19 14:18 +0200
      Re: continue equivalent in Forth? mhx@iae.nl (Marcel Hendrix) - 2012-08-19 14:57 +0200
        Re: continue equivalent in Forth? Coos Haak <chforth@hccnet.nl> - 2012-08-19 16:39 +0200
      Re: continue equivalent in Forth? "Ed" <invalid@nospam.com> - 2012-08-20 22:18 +1000
      Re: continue equivalent in Forth? "Rod Pemberton" <do_not_have@notemailnot.cmm> - 2012-08-21 00:05 -0400
        Re: continue equivalent in Forth? hughaguilar96@yahoo.com - 2012-08-20 21:17 -0700
          Re: continue equivalent in Forth? Alex McDonald <blog@rivadpm.com> - 2012-08-21 02:40 -0700
          Re: continue equivalent in Forth? "Ed" <invalid@nospam.com> - 2012-08-22 15:33 +1000
        Re: continue equivalent in Forth? Alex McDonald <blog@rivadpm.com> - 2012-08-21 02:37 -0700
          Re: continue equivalent in Forth? "Rod Pemberton" <do_not_have@notemailnot.cmm> - 2012-08-22 00:53 -0400
            Re: continue equivalent in Forth? Alex McDonald <blog@rivadpm.com> - 2012-08-22 04:10 -0700
        Re: continue equivalent in Forth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-08-21 11:40 +0000
          Re: continue equivalent in Forth? "Rod Pemberton" <do_not_have@notemailnot.cmm> - 2012-08-22 00:53 -0400
            Re: continue equivalent in Forth? "Elizabeth D. Rather" <erather@forth.com> - 2012-08-21 21:18 -1000
              Re: continue equivalent in Forth? hughaguilar96@yahoo.com - 2012-08-22 00:52 -0700
                Re: continue equivalent in Forth? Alex McDonald <blog@rivadpm.com> - 2012-08-22 04:12 -0700
                Re: continue equivalent in Forth? "Rod Pemberton" <do_not_have@notemailnot.cmm> - 2012-08-22 07:43 -0400
                Re: continue equivalent in Forth? hughaguilar96@yahoo.com - 2012-08-22 20:04 -0700
                Re: continue equivalent in Forth? "Ed" <invalid@nospam.com> - 2012-08-25 15:50 +1000
                Re: continue equivalent in Forth? "Elizabeth D. Rather" <erather@forth.com> - 2012-08-24 21:03 -1000
                Re: continue equivalent in Forth? "Ed" <invalid@nospam.com> - 2012-08-26 22:13 +1000
                Re: continue equivalent in Forth? Coos Haak <chforth@hccnet.nl> - 2012-08-25 10:40 +0200
                Re: continue equivalent in Forth? "Ed" <invalid@nospam.com> - 2012-08-29 18:29 +1000
                Re: continue equivalent in Forth? Coos Haak <chforth@hccnet.nl> - 2012-08-29 21:26 +0200
                Re: continue equivalent in Forth? "Ed" <invalid@nospam.com> - 2012-08-26 22:33 +1000
              Re: continue equivalent in Forth? "Rod Pemberton" <do_not_have@notemailnot.cmm> - 2012-08-22 07:46 -0400
                Re: continue equivalent in Forth? "Elizabeth D. Rather" <erather@forth.com> - 2012-08-22 07:20 -1000
            Re: continue equivalent in Forth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-08-22 09:37 +0000
              Re: continue equivalent in Forth? "Ed" <invalid@nospam.com> - 2012-08-22 20:46 +1000
              Re: continue equivalent in Forth? "Rod Pemberton" <do_not_have@notemailnot.cmm> - 2012-08-22 07:44 -0400
                Re: continue equivalent in Forth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-08-22 14:26 +0000
                Re: continue equivalent in Forth? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2012-08-24 17:34 +0100
                Re: continue equivalent in Forth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-08-24 16:50 +0000
                Re: continue equivalent in Forth? Mark Wills <markrobertwills@yahoo.co.uk> - 2012-08-24 13:47 -0700
                Re: continue equivalent in Forth? mhx@iae.nl - 2012-08-24 22:51 -0700
                Re: continue equivalent in Forth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-08-25 08:55 +0000
                Re: continue equivalent in Forth? hughaguilar96@yahoo.com - 2012-08-25 20:47 -0700
                Re: continue equivalent in Forth? "Rod Pemberton" <do_not_have@notemailnot.cmm> - 2012-08-26 06:20 -0400
                Re: continue equivalent in Forth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-08-26 11:04 -0500
                Re: continue equivalent in Forth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-08-26 16:06 +0000
                Re: continue equivalent in Forth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-08-26 15:32 -0500
                Re: continue equivalent in Forth? Hugh Aguilar <hughaguilar96@yahoo.com> - 2012-08-27 22:58 -0700
                Re: continue equivalent in Forth? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2012-08-26 22:07 +0100
                Re: continue equivalent in Forth? mhx@iae.nl (Marcel Hendrix) - 2012-08-27 18:14 +0200
                Re: continue equivalent in Forth? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2012-08-27 18:22 +0100
                Re: continue equivalent in Forth? mhx@iae.nl (Marcel Hendrix) - 2012-08-27 20:45 +0200
                Re: continue equivalent in Forth? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2012-08-27 21:43 +0100
                Re: continue equivalent in Forth? "Elizabeth D. Rather" <erather@forth.com> - 2012-08-27 12:15 -1000
                Re: continue equivalent in Forth? mhx@iae.nl (Marcel Hendrix) - 2012-08-28 20:43 +0200
                Re: continue equivalent in Forth? "Ed" <invalid@nospam.com> - 2012-08-29 17:10 +1000
                Re: continue equivalent in Forth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-08-28 15:56 +0000
                Re: continue equivalent in Forth? mhx@iae.nl (Marcel Hendrix) - 2012-08-28 20:35 +0200
                Re: continue equivalent in Forth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-08-30 12:32 +0000
                Re: continue equivalent in Forth? mhx@iae.nl (Marcel Hendrix) - 2012-08-30 22:39 +0200
                Re: continue equivalent in Forth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-08-31 09:14 +0000
                Re: continue equivalent in Forth? mhx@iae.nl (Marcel Hendrix) - 2012-08-31 21:32 +0200
                Re: continue equivalent in Forth? "Ed" <invalid@nospam.com> - 2012-09-02 20:30 +1000
                Re: continue equivalent in Forth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-09-02 13:15 +0000
                Re: continue equivalent in Forth? "Ed" <invalid@nospam.com> - 2012-08-31 18:27 +1000
                Re: continue equivalent in Forth? mhx@iae.nl (Marcel Hendrix) - 2012-08-31 20:39 +0200
                Re: continue equivalent in Forth? "Ed" <invalid@nospam.com> - 2012-09-01 14:28 +1000
          Re: continue equivalent in Forth? hughaguilar96@yahoo.com - 2012-08-21 22:59 -0700
        Re: continue equivalent in Forth? Bernd Paysan <bernd.paysan@gmx.de> - 2012-08-21 20:49 +0200
          Re: continue equivalent in Forth? "Rod Pemberton" <do_not_have@notemailnot.cmm> - 2012-08-22 07:46 -0400
            Re: continue equivalent in Forth? Bernd Paysan <bernd.paysan@gmx.de> - 2012-08-22 16:24 +0200
    Re: continue equivalent in Forth? programmingkidx@gmail.com - 2012-08-19 14:37 -0700
      Re: continue equivalent in Forth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-08-20 05:17 -0500
      Re: continue equivalent in Forth? "Ed" <invalid@nospam.com> - 2012-08-20 22:34 +1000
      Re: continue equivalent in Forth? "Ed" <invalid@nospam.com> - 2012-08-20 23:01 +1000
      Re: continue equivalent in Forth? stephenXXX@mpeforth.com (Stephen Pelc) - 2012-08-21 08:34 +0000
        Re: continue equivalent in Forth? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2012-08-21 15:53 +0100
  Re: continue equivalent in Forth? "Rod Pemberton" <do_not_have@notemailnot.cmm> - 2012-08-19 11:00 -0400
    Re: continue equivalent in Forth? Coos Haak <chforth@hccnet.nl> - 2012-08-19 20:29 +0200
      Re: continue equivalent in Forth? "Rod Pemberton" <do_not_have@notemailnot.cmm> - 2012-08-21 00:04 -0400
    Re: continue equivalent in Forth? programmingkidx@gmail.com - 2012-08-19 14:09 -0700
  Re: continue equivalent in Forth? Mark Wills <markrobertwills@yahoo.co.uk> - 2012-08-19 11:31 -0700
    Re: continue equivalent in Forth? programmingkidx@gmail.com - 2012-08-19 14:43 -0700

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