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Error returns and repeated code, GOTOs, etc.

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  Error returns and repeated code, GOTOs, etc. mike3 <mike4ty4@yahoo.com> - 2012-05-29 22:44 -0700
    Re: Error returns and repeated code, GOTOs, etc. Ike Naar <ike@sverige.freeshell.org> - 2012-05-30 06:38 +0000
    Re: Error returns and repeated code, GOTOs, etc. Nils M Holm <news2009@t3x.org> - 2012-05-30 06:57 +0000
    Re: Error returns and repeated code, GOTOs, etc. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-05-30 00:52 -0700
      Re: Error returns and repeated code, GOTOs, etc. mike3 <mike4ty4@yahoo.com> - 2012-05-30 01:50 -0700
    Re: Error returns and repeated code, GOTOs, etc. MarkBluemel <mark_bluemel@pobox.com> - 2012-05-30 09:55 +0100
      Re: Error returns and repeated code, GOTOs, etc. Willem <willem@toad.stack.nl> - 2012-05-30 09:18 +0000
        Re: Error returns and repeated code, GOTOs, etc. tom st denis <tom@iahu.ca> - 2012-05-30 05:16 -0700
          Re: Error returns and repeated code, GOTOs, etc. Willem <willem@toad.stack.nl> - 2012-05-30 16:26 +0000
            Re: Error returns and repeated code, GOTOs, etc. tom st denis <tom@iahu.ca> - 2012-06-01 08:05 -0700
              Re: Error returns and repeated code, GOTOs, etc. Willem <willem@toad.stack.nl> - 2012-06-03 11:24 +0000
            Re: Error returns and repeated code, GOTOs, etc. jgk@panix.com (Joe keane) - 2012-06-02 13:54 +0000
              Re: Error returns and repeated code, GOTOs, etc. Jean-Christophe <5.d@free.fr> - 2012-06-02 07:24 -0700
                Re: Error returns and repeated code, GOTOs, etc. jgk@panix.com (Joe keane) - 2012-06-02 16:37 +0000
                  Re: Error returns and repeated code, GOTOs, etc. Jean-Christophe <5.d@free.fr> - 2012-06-02 12:46 -0700
              Re: Error returns and repeated code, GOTOs, etc. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-02 15:42 +0100
                Re: Error returns and repeated code, GOTOs, etc. jgk@panix.com (Joe keane) - 2012-06-02 19:35 +0000
                  Re: Error returns and repeated code, GOTOs, etc. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-03 03:53 +0100
                    Re: Error returns and repeated code, GOTOs, etc. Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-06-11 18:10 +0300
                      Re: Error returns and repeated code, GOTOs, etc. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-11 16:19 +0100
              Re: Error returns and repeated code, GOTOs, etc. Martin Shobe <martin.shobe@yahoo.com> - 2012-06-02 19:27 +0000
                Re: Error returns and repeated code, GOTOs, etc. jgk@panix.com (Joe keane) - 2012-06-03 23:48 +0000
                  Re: Error returns and repeated code, GOTOs, etc. Ian Collins <ian-news@hotmail.com> - 2012-06-04 11:53 +1200
                  Re: Error returns and repeated code, GOTOs, etc. Martin Shobe <martin.shobe@yahoo.com> - 2012-06-04 03:32 +0000
      Re: Error returns and repeated code, GOTOs, etc. nick_keighley_nospam@hotmail.com - 2012-05-30 07:25 -0700
      Re: Error returns and repeated code, GOTOs, etc. falk@rahul.net (Edward A. Falk) - 2012-06-05 07:20 +0000
    Re: Error returns and repeated code, GOTOs, etc. Ian Collins <ian-news@hotmail.com> - 2012-05-30 21:50 +1200
      Re: Error returns and repeated code, GOTOs, etc. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-05-30 03:34 -0700
        Re: Error returns and repeated code, GOTOs, etc. Ian Collins <ian-news@hotmail.com> - 2012-05-30 22:57 +1200
        Re: Error returns and repeated code, GOTOs, etc. Willem <willem@toad.stack.nl> - 2012-05-30 11:04 +0000
        Re: Error returns and repeated code, GOTOs, etc. nick_keighley_nospam@hotmail.com - 2012-05-30 04:53 -0700
    Re: Error returns and repeated code, GOTOs, etc. "BartC" <bc@freeuk.com> - 2012-05-30 13:28 +0100
      Re: Error returns and repeated code, GOTOs, etc. mike3 <mike4ty4@yahoo.com> - 2012-05-30 13:57 -0700
    Re: Error returns and repeated code, GOTOs, etc. "io_x" <a@b.c.invalid> - 2012-05-30 15:19 +0200
      Re: Error returns and repeated code, GOTOs, etc. Mark Bluemel <mark.bluemel@googlemail.com> - 2012-05-31 01:10 -0700
      Re: Error returns and repeated code, GOTOs, etc. "io_x" <a@b.c.invalid> - 2012-06-02 17:34 +0200
        Re: Error returns and repeated code, GOTOs, etc. "io_x" <a@b.c.invalid> - 2012-06-03 10:33 +0200
    Re: Error returns and repeated code, GOTOs, etc. Ike Naar <ike@iceland.freeshell.org> - 2012-05-30 13:56 +0000
      Re: Error returns and repeated code, GOTOs, etc. Kulin <remailer@reece.net.au> - 2012-05-30 17:29 +0000
    Re: Error returns and repeated code, GOTOs, etc. ImpalerCore <jadill33@gmail.com> - 2012-05-30 07:13 -0700
      Re: Error returns and repeated code, GOTOs, etc. Thad Smith <ThadSmith@acm.org> - 2012-06-02 07:20 -0600
    Re: Error returns and repeated code, GOTOs, etc. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-05-30 16:37 +0100
    Re: Error returns and repeated code, GOTOs, etc. Johann Klammer <klammerj@NOSPAM.a1.net> - 2012-05-30 19:05 +0200
    Re: Error returns and repeated code, GOTOs, etc. Tim Rentsch <txr@alumni.caltech.edu> - 2012-05-31 13:19 -0700
      Re: Error returns and repeated code, GOTOs, etc. mike3 <mike4ty4@yahoo.com> - 2012-05-31 13:49 -0700
        Re: Error returns and repeated code, GOTOs, etc. "BartC" <bc@freeuk.com> - 2012-05-31 22:08 +0100
          Re: Error returns and repeated code, GOTOs, etc. mike3 <mike4ty4@yahoo.com> - 2012-05-31 16:08 -0700
        Re: Error returns and repeated code, GOTOs, etc. Tim Rentsch <txr@alumni.caltech.edu> - 2012-05-31 17:34 -0700
        Re: Error returns and repeated code, GOTOs, etc. Willem <willem@toad.stack.nl> - 2012-06-01 07:40 +0000
    GOTOs discovered in "real world" program! (was Re: Error returns and repeated code, GOTOs, etc.) mike3 <mike4ty4@yahoo.com> - 2012-05-31 16:39 -0700
      Re: GOTOs discovered in "real world" program! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-01 03:21 +0100
        Re: GOTOs discovered in "real world" program! mike3 <mike4ty4@yahoo.com> - 2012-06-01 03:49 -0700
          Re: GOTOs discovered in "real world" program! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-02 02:15 +0100
            Re: GOTOs discovered in "real world" program! mike3 <mike4ty4@yahoo.com> - 2012-06-01 19:45 -0700
              Re: GOTOs discovered in "real world" program! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-02 15:00 +0100
                Re: GOTOs discovered in "real world" program! mike3 <mike4ty4@yahoo.com> - 2012-06-02 16:44 -0700
                  Re: GOTOs discovered in "real world" program! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-03 03:51 +0100
        Re: GOTOs discovered in "real world" program! "Aaron W.  Hsu" <arcfide@sacrideo.us> - 2012-06-01 12:06 -0400
          Re: GOTOs discovered in "real world" program! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-02 02:01 +0100
            Re: GOTOs discovered in "real world" program! mike3 <mike4ty4@yahoo.com> - 2012-06-01 19:46 -0700
              Re: GOTOs discovered in "real world" program! mike3 <mike4ty4@yahoo.com> - 2012-06-01 21:19 -0700
                Re: GOTOs discovered in "real world" program! blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2012-06-02 16:35 +0000
              Re: GOTOs discovered in "real world" program! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-02 14:50 +0100
              Re: GOTOs discovered in "real world" program! Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-06-02 07:04 -0700
            Re: GOTOs discovered in "real world" program! "Aaron W. Hsu" <arcfide@sacrideo.us> - 2012-06-02 04:37 -0500
              Re: GOTOs discovered in "real world" program! mike3 <mike4ty4@yahoo.com> - 2012-06-02 03:40 -0700
                Re: GOTOs discovered in "real world" program! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-02 14:46 +0100
                  Re: GOTOs discovered in "real world" program! "BartC" <bc@freeuk.com> - 2012-06-02 17:10 +0100
                  Re: GOTOs discovered in "real world" program! Robert Wessel <robertwessel2@yahoo.com> - 2012-06-02 11:35 -0500
      Re: GOTOs discovered in "real world" program! (was Re: Error returns and repeated code, GOTOs, etc.) "BartC" <bc@freeuk.com> - 2012-06-02 09:46 +0100
        Re: GOTOs discovered in "real world" program! (was Re: Error returns and repeated code, GOTOs, etc.) "io_x" <a@b.c.invalid> - 2012-06-03 10:43 +0200
          Re: GOTOs discovered in "real world" program! (was Re: Error returns and repeated code, GOTOs, etc.) "BartC" <bc@freeuk.com> - 2012-06-03 10:58 +0100
            Re: GOTOs discovered in "real world" program! (was Re: Error returns and repeated code, GOTOs, etc.) "io_x" <a@b.c.invalid> - 2012-06-03 17:18 +0200
            Re: GOTOs discovered in "real world" program! (was Re: Error returns and repeated code, GOTOs, etc.) jgk@panix.com (Joe keane) - 2012-06-04 20:40 +0000
              Re: GOTOs discovered in "real world" program! (was Re: Error returns and repeated code, GOTOs, etc.) jgk@panix.com (Joe keane) - 2012-06-05 01:03 +0000
                Re: GOTOs discovered in "real world" program! Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2012-06-04 21:36 -0600
                  Re: GOTOs discovered in "real world" program! jgk@panix.com (Joe keane) - 2012-06-05 15:13 +0000
                Re: GOTOs discovered in "real world" program! (was Re: Error returns and repeated code, GOTOs, etc.) Ike Naar <ike@sverige.freeshell.org> - 2012-06-05 08:12 +0000
                  Re: GOTOs discovered in "real world" program! (was Re: Error returns and repeated code, GOTOs, etc.) James Kuyper <jameskuyper@verizon.net> - 2012-06-05 06:00 -0400
              Re: GOTOs discovered in "real world" program! (was Re: Error returns and repeated code, GOTOs, etc.) jgk@panix.com (Joe keane) - 2012-06-05 02:05 +0000
                Re: GOTOs discovered in "real world" program! (was Re: Error returns and repeated code, GOTOs, etc.) Martin Shobe <martin.shobe@yahoo.com> - 2012-06-05 03:16 +0000
          Re: GOTOs discovered in "real world" program! (was Re: Error returns and repeated code, GOTOs, etc.) "io_x" <a@b.c.invalid> - 2012-06-03 17:30 +0200
            Re: GOTOs discovered in "real world" program! (was Re: Error returns and repeated code, GOTOs, etc.) Jean-Christophe <5.d@free.fr> - 2012-06-03 09:02 -0700
              Re: GOTOs discovered in "real world" program! (was Re: Error returns and repeated code, GOTOs, etc.) Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-03 22:37 +0100
                Re: GOTOs discovered in "real world" program! (was Re: Error returns and repeated code, GOTOs, etc.) Ike Naar <ike@iceland.freeshell.org> - 2012-06-04 07:28 +0000
                Re: GOTOs discovered in "real world" program! (was Re: Error returns and repeated code, GOTOs, etc.) Tim Rentsch <txr@alumni.caltech.edu> - 2012-06-08 01:28 -0700
      Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) mike3 <mike4ty4@yahoo.com> - 2012-06-06 02:54 -0700
        Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-06 13:14 +0100
          Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) pete <pfiland@mindspring.com> - 2012-06-06 09:22 -0400
            Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) Willem <willem@toad.stack.nl> - 2012-06-06 13:49 +0000
              Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) Rui Maciel <rui.maciel@gmail.com> - 2012-06-06 14:56 +0100
              Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) James Kuyper <jameskuyper@verizon.net> - 2012-06-06 10:17 -0400
        Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) Angel <angel+news@spamcop.net> - 2012-06-06 13:06 +0000
          Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) mike3 <mike4ty4@yahoo.com> - 2012-06-07 16:26 -0700
            Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) Angel <angel+news@spamcop.net> - 2012-06-08 14:26 +0000
              Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) mike3 <mike4ty4@yahoo.com> - 2012-06-08 15:19 -0700
                Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) Angel <angel+news@spamcop.net> - 2012-06-08 23:32 +0000
                Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) "BartC" <bc@freeuk.com> - 2012-06-09 01:14 +0100
                  Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) Jean-Christophe <5.d@free.fr> - 2012-06-09 04:36 -0700
                  Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-06-09 05:54 -0700
                    Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) "BartC" <bc@freeuk.com> - 2012-06-09 16:12 +0100
                      Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-06-09 08:44 -0700
                        Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) "io_x" <a@b.c.invalid> - 2012-06-10 18:23 +0200
                          Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) "io_x" <a@b.c.invalid> - 2012-06-10 19:42 +0200
                            Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) "io_x" <a@b.c.invalid> - 2012-06-14 18:00 +0200
                          Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) nick_keighley_nospam@hotmail.com - 2012-06-11 01:14 -0700
                            Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) "io_x" <a@b.c.invalid> - 2012-06-12 08:01 +0200
                              Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) nick_keighley_nospam@hotmail.com - 2012-06-12 05:27 -0700
                            Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) "io_x" <a@b.c.invalid> - 2012-06-12 08:44 +0200
                    Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) jgk@panix.com (Joe keane) - 2012-06-11 17:24 +0000
                      Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) "BartC" <bc@freeuk.com> - 2012-06-11 19:02 +0100
                        Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) jgk@panix.com (Joe keane) - 2012-06-12 20:03 +0000
                          Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) nick_keighley_nospam@hotmail.com - 2012-06-13 00:58 -0700
                            Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) James Kuyper <jameskuyper@verizon.net> - 2012-06-13 06:37 -0400
                              Evil in Programming   Was: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) nick_keighley_nospam@hotmail.com - 2012-06-13 04:50 -0700
                            Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) gwowen <gwowen@gmail.com> - 2012-06-13 07:02 -0700
                            Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) Les Cargill <lcargill99@comcast.com> - 2012-06-13 12:47 -0500
                              Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) James Kuyper <jameskuyper@verizon.net> - 2012-06-13 14:17 -0400
                                Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) Willem <willem@toad.stack.nl> - 2012-06-13 19:44 +0000
                                  Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) James Kuyper <jameskuyper@verizon.net> - 2012-06-13 15:52 -0400
                                Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) Les Cargill <lcargill99@comcast.com> - 2012-06-13 17:45 -0500
                                  Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) James Kuyper <jameskuyper@verizon.net> - 2012-06-13 19:07 -0400
                                Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) jgk@panix.com (Joe keane) - 2012-06-14 23:03 +0000
                                Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) Kaz Kylheku <kaz@kylheku.com> - 2012-06-14 23:25 +0000
                                  Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) Les Cargill <lcargill99@comcast.com> - 2012-06-14 19:25 -0500
                                    Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) 88888 Dihedral <dihedral88888@googlemail.com> - 2012-06-17 20:32 -0700
                                      Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) nick_keighley_nospam@hotmail.com - 2012-06-18 01:30 -0700
                                        Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) Les Cargill <lcargill99@comcast.com> - 2012-06-18 07:06 -0500
                            Re: Why was there a GOTO? Gareth Owen <gwowen@gmail.com> - 2012-06-13 19:57 +0100
                  Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!) jgk@panix.com (Joe keane) - 2012-06-10 16:56 +0000
    Another problem (was Re: Error returns and repeated code, GOTOs, etc.) mike3 <mike4ty4@yahoo.com> - 2012-05-31 16:46 -0700
      Re: Another problem (was Re: Error returns and repeated code, GOTOs, etc.) Ian Collins <ian-news@hotmail.com> - 2012-06-01 15:55 +1200
    Re: Error returns and repeated code, GOTOs, etc. gwowen <gwowen@gmail.com> - 2012-06-06 08:12 -0700

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#22066 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

"Malcolm McLean" <malcolm.mclean5@btinternet.com> wrote in message 
news:538a3102-833f-4a0b-a790-733cc91629fa@googlegroups.com...
> בתאריך יום שבת, 9 ביוני 2012 01:14:43 UTC+1, מאת Bart:
>>
>> If you take the function with the gotos, and simplify the structure, it
>> looks like this:
....

> The central mistake is that the the consturctor takes an empty structure 
> to fill in, rather than returning a pointer to an allocated structure. 
> Then the destructor itself can return an error.
> Change this, and you get
>
>     Init(a); if(x) goto f0;
>     Init(b); if(x) goto f0;
>     Init(c); if(x) goto f0;
>     Init(d); if(x) goto f0;
>
>     Set(b,3);  if(x) goto f0;
>
>     Free(d);
>     Free(c);
>     Free(b);
>     Free(a);
>     return(p);
>
> f0: Free(d);
>     Free(c);
>     Free(b);
>     Free(a);
>     return(q);
>
> That's much mpre acceptable. The control flow is still doiminated by 
> gotos, but that's because all the calls can return errors, which go into a 
> single error handler.

Yes. And now the two blocks of Frees are almost identical, and they can be 
combined into one. At that point you'll probably change the initialisation 
to be something like:

 if (Init(a) && Init(b) ... )
   Set(b,3);
 Free(d);
 ...

However there is the requirement to return one of several error codes, 
either from the first failing Init(), from a failing Set(), or from a first 
failing Free() (but in case of a failure here, all remaining objects must 
still be freed).

It's this elevating the importance of an error return far above that of any 
actual results, that is causing the difficulties. The design needs more work 
to make it easier to manage allocation and returns, otherwise programming 
anything non-trivial (or even trivial!) will be impossible.

-- 
Bartc 

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#22069 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

בתאריך יום שבת, 9 ביוני 2012 16:12:51 UTC+1, מאת Bart:
> "Malcolm McLean" <malcolm.mclean5@btinternet.com> wrote in message 
> 
> However there is the requirement to return one of several error codes, 
> either from the first failing Init(), from a failing Set(), or from a first 
> failing Free() (but in case of a failure here, all remaining objects must 
> still be freed).
>
Usually two things can go wrong. Either there was a programming error, or the
 computer ran out of memory.

If there's a programming error, fundamentally there's nothing good you can do.
 If the computer ran out of memory, usually that indicates a programming error
 (sensible integers can't exceed the memory capacity of a 4gigabyte machine).
 The problem with C is that you have to handle and report the situation.
> 
> It's this elevating the importance of an error return far above that of any 
> actual results, that is causing the difficulties. The design needs more work 
> to make it easier to manage allocation and returns, otherwise programming 
> anything non-trivial (or even trivial!) will be impossible.
> 
C doesn't distinguish between error processing and the normal control paths.
 But you can keep such a distinction, by defing a label error_exit; Once
 you've jumped to that able, the program is in error state. Generally you
 need to pass up error returns through the call stack, until some function
 knows whether it's better to suppress the error, inform the user, or terminate.

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#22093 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

"Malcolm McLean" <malcolm.mclean5@btinternet.com> ha scritto nel messaggio 
news:7d436013-af84-4200-a84e-06064eac46fe@googlegroups.com...
?????? ??? ???, 9 ????? 2012 16:12:51 UTC+1, ??? Bart:
> "Malcolm McLean" <malcolm.mclean5@btinternet.com> wrote in message
>
> However there is the requirement to return one of several error codes,
> either from the first failing Init(), from a failing Set(), or from a first
> failing Free() (but in case of a failure here, all remaining objects must
> still be freed).
>
Usually two things can go wrong. Either there was a programming error, or the
 computer ran out of memory.

If there's a programming error, fundamentally there's nothing good you can do.

#but i know *there is some error* for correct it, and where the error is...
#i make errors, it is for this, each single bit for find-correct error is good
#is not a .exe space problem, not a time problem...
#but possibly all you not make errors, so not have the need to
#find-correct them...

 If the computer ran out of memory, usually that indicates a programming error
 (sensible integers can't exceed the memory capacity of a 4gigabyte machine).

 The problem with C is that you have to handle and report the situation.

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#22097 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

"io_x" <a@b.c.invalid> ha scritto nel messaggio
news:4fd4c8a8$0$1389$4fafbaef@reader2.news.tin.it...
>
> "Malcolm McLean" <malcolm.mclean5@btinternet.com> ha scritto nel messaggio
> news:7d436013-af84-4200-a84e-06064eac46fe@googlegroups.com...
> ?????? ??? ???, 9 ????? 2012 16:12:51 UTC+1, ??? Bart:
>> "Malcolm McLean" <malcolm.mclean5@btinternet.com> wrote in message
>>
>> However there is the requirement to return one of several error codes,
>> either from the first failing Init(), from a failing Set(), or from a first
>> failing Free() (but in case of a failure here, all remaining objects must
>> still be freed).
>>
> Usually two things can go wrong. Either there was a programming error, or the
> computer ran out of memory.
>
> If there's a programming error, fundamentally there's nothing good you can do.

possibly i not understand well
yes in the big num library i use, in C++ language
i have not a way for find errors
for example what to do if i have

num  x,y,z,t, tmp;

x=(x+3)*z*t;

and the only error can occur, or can be seen or catch, it is the out of memory
error ...
so what you say it is what i thought: are you a mind reader?

in case of out of memory error here the program should exit from above...
[constructor of x, z, etc if malloc return null exit(), the same
* and + if the num can not be allocated exit()]

asm routine that calulate operations on x, z, t can find some arg error
or possibly other errors, but i never find a way for use the information
in the C++ language side at last in compose operations...

so: could be useful find error even if the only cachable errors are the
ones of out of memory errors?

is there someone from all you that know what i can do for find error
without exceptions in the big num library?

i find a way, some little add of code in each assembly functions
and some space in each number...but i don't know if could be ok
or could be usefull...

> #but i know *there is some error* for correct it, and where the error is...
> #i make errors, it is for this, each single bit for find-correct error is good
> #is not a .exe space problem, not a time problem...
> #but possibly all you not make errors, so not have the need to
> #find-correct them...
>
> If the computer ran out of memory, usually that indicates a programming error
> (sensible integers can't exceed the memory capacity of a 4gigabyte machine).
>
> The problem with C is that you have to handle and report the situation.
>
>

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#22267 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

"io_x" <a@b.c.invalid> ha scritto nel messaggio
news:4fd4db70$0$1386$4fafbaef@reader2.news.tin.it...
> possibly i not understand well
> yes in the big num library i use, in C++ language
> i have not a way for find errors
> for example what to do if i have
>
> num  x,y,z,t, tmp;
>
> x=(x+3)*z*t;
>
> and the only error can occur, or can be seen or catch, it is the out of memory
> error ...
> so what you say it is what i thought: are you a mind reader?
>
> in case of out of memory error here the program should exit from above...
> [constructor of x, z, etc if malloc return null exit(), the same
> * and + if the num can not be allocated exit()]
>
> asm routine that calulate operations on x, z, t can find some arg error
> or possibly other errors,

i remembered wrong, my asm-big number routines have not error check...
possibly i wrote them before my obsession for find errors...
so all operation on big num will not report error, the only error is out
of memory

> but i never find a way for use the information
> in the C++ language side at last in compose operations...
>
> so: could be useful find error even if the only cachable errors are the
> ones of out of memory errors?
>
> is there someone from all you that know what i can do for find error
> without exceptions in the big num library?
>
> i find a way, some little add of code in each assembly functions
> and some space in each number...but i don't know if could be ok
> or could be usefull...

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#22102 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

On Sunday, June 10, 2012 5:23:18 PM UTC+1, io_x wrote:
> "Malcolm McLean" <malcolm.mclean5@btinternet.com> ha scritto nel messaggio 
> news:7d436013-af84-4200-a84e-06064eac46fe@googlegroups.com...

<snip>

against my better judgement I'm goign to try a decode one of io_x's posts

> Usually two things can go wrong. Either there was a programming error, or the
>  computer ran out of memory.
> 
> If there's a programming error, fundamentally there's nothing good you can do.
> 
> #but i know *there is some error* for correct it, and where the error is...
> #i make errors, it is for this, each single bit for find-correct error is good
> #is not a .exe space problem, not a time problem...
> #but possibly all you not make errors, so not have the need to
> #find-correct them...

are you trying to say something like this:-

"but even in the case of a programming error a good diagnostic 
will tell you at least where the error occurred; and the more 
information that can be provided the easier it is to track down 
the root cause. Perhaps the rest of you don't make programming errors!"

if so I have some sympathy. The humble assert() should not be neglected.
Perhaps your unit tests need to be improved?

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#22139 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

<nick_keighley_nospam@hotmail.com> ha scritto nel messaggio 
news:8c647bfc-4310-4d17-91df-6523923a51f2@googlegroups.com...
> On Sunday, June 10, 2012 5:23:18 PM UTC+1, io_x wrote:
>> "Malcolm McLean" <malcolm.mclean5@btinternet.com> ha scritto nel messaggio
>> news:7d436013-af84-4200-a84e-06064eac46fe@googlegroups.com...
>
> <snip>
>
> against my better judgement I'm goign to try a decode one of io_x's posts
>
>> Usually two things can go wrong. Either there was a programming error, or the
>>  computer ran out of memory.
>>
>> If there's a programming error, fundamentally there's nothing good you can 
>> do.
>>
>> #but i know *there is some error* for correct it, and where the error is...
>> #i make errors, it is for this, each single bit for find-correct error is 
>> good
>> #is not a .exe space problem, not a time problem...
>> #but possibly all you not make errors, so not have the need to
>> #find-correct them...
>
> are you trying to say something like this:-
>
> "but even in the case of a programming error a good diagnostic
> will tell you at least where the error occurred;

the error occurred and where; the problem is one presumible little
slow down... but if someone search for error search in memory allready
load or that has to be load for doing the calculation

> and the more
> information that can be provided the easier it is to track down
> the root cause. Perhaps the rest of you don't make programming errors!"
>
> if so I have some sympathy. The humble assert() should not be neglected.
> Perhaps your unit tests need to be improved?

i not use assert()

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#22152 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

On Tuesday, June 12, 2012 7:01:09 AM UTC+1, io_x wrote:
> <nick_keighley_nospam@hotmail.com> ha scritto nel messaggio 
> news:8c647bfc-4310-4d17-91df-6523923a51f2@googlegroups.com...
> > On Sunday, June 10, 2012 5:23:18 PM UTC+1, io_x wrote:
> >> "Malcolm McLean" <malcolm.mclean5@btinternet.com> ha scritto nel messaggio
> >> news:7d436013-af84-4200-a84e-06064eac46fe@googlegroups.com...

> > against my better judgement I'm goign to try a decode one of io_x's posts
> >
> >> Usually two things can go wrong. Either there was a programming error, 
> >> or the computer ran out of memory.
> >>
> >> If there's a programming error, fundamentally there's nothing good you can 
> >> do.
> >>
> >> #but i know *there is some error* for correct it, and where the error is...
> >> #i make errors, it is for this, each single bit for find-correct error is 
> >> good
> >> #is not a .exe space problem, not a time problem...
> >> #but possibly all you not make errors, so not have the need to
> >> #find-correct them...
> >
> > are you trying to say something like this:-
> >
> > "but even in the case of a programming error a good diagnostic
> > will tell you at least where the error occurred;
> 
> the error occurred and where; the problem is one presumible little
> slow down...

"it may slow the program down a little"?

> but if someone search for error search in memory allready
> load or that has to be load for doing the calculation

sorry I haven't taken the advanced class in gibberish!

> > and the more
> > information that can be provided the easier it is to track down
> > the root cause. Perhaps the rest of you don't make programming errors!"
> >
> > if so I have some sympathy. The humble assert() should not be neglected.
> > Perhaps your unit tests need to be improved?
> 
> i not use assert()

no surprise!

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#22140 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

<nick_keighley_nospam@hotmail.com> ha scritto nel messaggio
news:8c647bfc-4310-4d17-91df-6523923a51f2@googlegroups.com...
> if so I have some sympathy. The humble assert() should not be neglected.
> Perhaps your unit tests need to be improved?

yes for unit test; i'm implementing the first only now...
but it do not a full test, some routine not too much long
for see if something it is wrong...

for assert:
i see in this way
from this function

int  fun(void*  p)
{// define new varibles

 assert(p!=NULL);
 ....
}

i always prefer:
int  fun(void*  p)
{// define new varibles

 if(p==NULL)  return -1;
 ....
}

it is because it is not fun() that has to work with the error
but it is the function that call fun()
it seem recursive...
this is the only reason i have for think that

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#22119 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

In article <538a3102-833f-4a0b-a790-733cc91629fa@googlegroups.com>,
Malcolm McLean  <malcolm.mclean5@btinternet.com> wrote:
>     Init(a); if(x) goto f0;
>     Init(b); if(x) goto f0;
>     Init(c); if(x) goto f0;
>     Init(d); if(x) goto f0;
> 
>     Set(b,3);  if(x) goto f0;
> 
>     Free(d); 
>     Free(c); 
>     Free(b); 
>     Free(a);
>     return(p);
> 
> f0: Free(d);
>     Free(c);
>     Free(b);
>     Free(a);
>     return(q);

This code looks wrong.

If 'Init(a)' fails, then we go to 'Free(d)'?

I'm sure that you can make it work, somehow.

My point is that error handling is not that hard: if some 'allocate'
fails we go to the 'unallocate' of the previous one.

If you follow this rule, you should have correct code.

If you try to get 'clever' about it, that's when mistakes slip in.
Mistakes in error handling suck.

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#22120 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

"Joe keane" <jgk@panix.com> wrote in message
news:jr59ko$443$1@reader1.panix.com...
> In article <538a3102-833f-4a0b-a790-733cc91629fa@googlegroups.com>,
> Malcolm McLean  <malcolm.mclean5@btinternet.com> wrote:
>>     Init(a); if(x) goto f0;
>>     Init(b); if(x) goto f0;
>>     Init(c); if(x) goto f0;
>>     Init(d); if(x) goto f0;
>>
>>     Set(b,3);  if(x) goto f0;
>>
>>     Free(d);
>>     Free(c);
>>     Free(b);
>>     Free(a);
>>     return(p);
>>
>> f0: Free(d);
>>     Free(c);
>>     Free(b);
>>     Free(a);
>>     return(q);
>
> This code looks wrong.
>
> If 'Init(a)' fails, then we go to 'Free(d)'?
>
> I'm sure that you can make it work, somehow.

I think the idea was that an unconditional Free() is used, where it knows
(even without a formal Init()) whether a particular object needs freeing. 
(For example, where an object is a pointer set to NULL.)

> My point is that error handling is not that hard: if some 'allocate'
> fails we go to the 'unallocate' of the previous one.

But the logic for that can become labyrinthic. (Eg. suppose each of the
previous Inits() were conditional, or initialised in an different order each 
time?)

There are other approaches to just freeing everything on exit; perhaps each
Init() can add an object to a local list of objects that need freeing, then
only those need to be checked on a common exit. This is useful where there
are large numbers of objects of which only some might be active at any time,
or it fails early on.

> If you try to get 'clever' about it, that's when mistakes slip in.
> Mistakes in error handling suck.

Have a look at the OP's original code: the one with gotos, and the one
without. The latter especially is quite long-winded, and likely to be more
error-prone that something a lot shorter.

-- 
Bartc 

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#22180 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

In article <jr5brl$i6r$1@dont-email.me>, BartC <bc@freeuk.com> wrote:
>Have a look at the OP's original code: the one with gotos, and the one
>without. The latter especially is quite long-winded, and likely to be more
>error-prone that something a lot shorter.

I think we're violently in agreement here: trying to make code
goto-free, because 'all gotos are evil', results in code that is more
bulky and more error-prone.

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#22192 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

On Tuesday, June 12, 2012 9:03:00 PM UTC+1, Joe keane wrote:
> In article <jr5brl$i6r$1@dont-email.me>, BartC <bc@freeuk.com> wrote:

> >Have a look at the OP's original code: the one with gotos, and the one
> >without. The latter especially is quite long-winded, and likely to be more
> >error-prone that something a lot shorter.
> 
> I think we're violently in agreement here: trying to make code
> goto-free, because 'all gotos are evil', results in code that is more
> bulky and more error-prone.

you may be in agreement but many posters on this thread are not.
(just when did "evil" become a fashionable word to use in programming? And why?)

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#22196 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

On 06/13/2012 03:58 AM, nick_keighley_nospam@hotmail.com wrote:
> On Tuesday, June 12, 2012 9:03:00 PM UTC+1, Joe keane wrote:
>> In article <jr5brl$i6r$1@dont-email.me>, BartC <bc@freeuk.com> wrote:
> 
>>> Have a look at the OP's original code: the one with gotos, and the one
>>> without. The latter especially is quite long-winded, and likely to be more
>>> error-prone that something a lot shorter.
>>
>> I think we're violently in agreement here: trying to make code
>> goto-free, because 'all gotos are evil', results in code that is more
>> bulky and more error-prone.
> 
> you may be in agreement but many posters on this thread are not.
> (just when did "evil" become a fashionable word to use in programming? And why?)

According to groups.google.com, the first use of 'evil' in the comp.*
hierarchy was on 1986-11-09, just 13 days after the first message posted
to that hierarchy. I think it was already fashionable at that time, but
I don't know any easy way to determine when that happened.
-- 
James Kuyper

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#22201 — Evil in Programming Was: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

On Wednesday, June 13, 2012 11:37:26 AM UTC+1, James Kuyper wrote:
> On 06/13/2012 03:58 AM, nick_keighley_nospam@hotmail.com wrote:

<snip>

> > (just when did "evil" become a fashionable word to use in 
> > programming? And why?)
> 
> According to groups.google.com, the first use of 'evil' in the comp.*
> hierarchy was on 1986-11-09, just 13 days after the first message posted
> to that hierarchy. I think it was already fashionable at that time, but
> I don't know any easy way to determine when that happened.

ah so there is nothing new under the sun. I'd only recently encountered this usage (the C++ FAQ uses it a lot) so I assumed it was some "new fangled" thing. I'd use words like "ill-advised" or "indicitive of potential problems" but "evil" is shorter...

I have a similar teeth gritting reflex when I come across "code smell"

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#22213 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

On Jun 13, 8:58 am, nick_keighley_nos...@hotmail.com wrote:

> you may be in agreement but many posters on this thread are not.
> (just when did "evil" become a fashionable word to use in programming? And why?)

Looking at http://www.catb.org/jargon/oldversions/ it makes it into
the Jargon File some time about revision 2.1.5 (November 1990).

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#22216 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

nick_keighley_nospam@hotmail.com wrote:
> On Tuesday, June 12, 2012 9:03:00 PM UTC+1, Joe keane wrote:
>> In article <jr5brl$i6r$1@dont-email.me>, BartC <bc@freeuk.com> wrote:
>
>>> Have a look at the OP's original code: the one with gotos, and the one
>>> without. The latter especially is quite long-winded, and likely to be more
>>> error-prone that something a lot shorter.
>>
>> I think we're violently in agreement here: trying to make code
>> goto-free, because 'all gotos are evil', results in code that is more
>> bulky and more error-prone.
>
> you may be in agreement but many posters on this thread are not.
> (just when did "evil" become a fashionable word to use in programming? And why?)
>

When people stopped thinking about it. Any use of the word "evil" is a
signal that the speaker has stopped thinking about it.

--
Les Cargill

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#22217 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

On 06/13/2012 01:47 PM, Les Cargill wrote:
> nick_keighley_nospam@hotmail.com wrote:
>> On Tuesday, June 12, 2012 9:03:00 PM UTC+1, Joe keane wrote:
>>> In article <jr5brl$i6r$1@dont-email.me>, BartC <bc@freeuk.com> wrote:
>>
>>>> Have a look at the OP's original code: the one with gotos, and the one
>>>> without. The latter especially is quite long-winded, and likely to be more
>>>> error-prone that something a lot shorter.
>>>
>>> I think we're violently in agreement here: trying to make code
>>> goto-free, because 'all gotos are evil', results in code that is more
>>> bulky and more error-prone.
>>
>> you may be in agreement but many posters on this thread are not.
>> (just when did "evil" become a fashionable word to use in programming? And why?)
>>
> 
> When people stopped thinking about it. Any use of the word "evil" is a
> signal that the speaker has stopped thinking about it.

You just used that word. :-)

There's nothing wrong with stopping thinking about something, so long as
you've completed your thinking about it, and have moved on to thinking
about something else. I think perhaps you intended to say something like
"... has not given sufficient thought to it."
If so, I would disagree - I think it's perfectly possible to give
sufficient thought to something, and come to the conclusion that it can
be described as "evil". It's a normative judgement, and as such
inherently subjective, but no more or less so than "good".

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#22219 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

James Kuyper wrote:
) On 06/13/2012 01:47 PM, Les Cargill wrote:
)> When people stopped thinking about it. Any use of the word "evil" is a
)> signal that the speaker has stopped thinking about it.
)
) You just used that word. :-)
)
) There's nothing wrong with stopping thinking about something, so long as
) you've completed your thinking about it, and have moved on to thinking
) about something else. I think perhaps you intended to say something like
) "... has not given sufficient thought to it."
) If so, I would disagree - I think it's perfectly possible to give
) sufficient thought to something, and come to the conclusion that it can
) be described as "evil". It's a normative judgement, and as such
) inherently subjective, but no more or less so than "good".

To paraphrase:

" I think you meant to say something else, which I disagree
  with, however I do agree with what you actually said. "

Debate club much?


SaSW, Willem
-- 
Disclaimer: I am in no way responsible for any of the statements
            made in the above text. For all I know I might be
            drugged or something..
            No I'm not paranoid. You all think I'm paranoid, don't you !
#EOT

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#22220 — Re: Why was there a GOTO? (was Re: GOTOs discovered in "real world" program!)

On 06/13/2012 03:44 PM, Willem wrote:
> James Kuyper wrote:
> ) On 06/13/2012 01:47 PM, Les Cargill wrote:
> )> When people stopped thinking about it. Any use of the word "evil" is a
> )> signal that the speaker has stopped thinking about it.
> )
> ) You just used that word. :-)
> )
> ) There's nothing wrong with stopping thinking about something, so long as
> ) you've completed your thinking about it, and have moved on to thinking
> ) about something else. I think perhaps you intended to say something like
> ) "... has not given sufficient thought to it."
> ) If so, I would disagree - I think it's perfectly possible to give
> ) sufficient thought to something, and come to the conclusion that it can
> ) be described as "evil". It's a normative judgement, and as such
> ) inherently subjective, but no more or less so than "good".
> 
> To paraphrase:
> 
> " I think you meant to say something else, which I disagree
>   with, however I do agree with what you actually said. "

If he meant what he actually said, there was little point in saying it,
at least in this context. If my guess about what he meant to say is
correct, there was a point in saying it, at least from the point of view
of someone who believes it to be true. I've heard similar sentiments
expressed before, often enough to justify considering the possibility
that it is indeed what he meant to say.

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