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


Groups > comp.lang.forth > #33535

Re: does VFX have the same bug as Gforth?

From Bernd Paysan <bernd.paysan@gmx.de>
Newsgroups comp.lang.forth
Subject Re: does VFX have the same bug as Gforth?
Date 2014-09-23 23:01 +0200
Organization 1&1 Internet AG
Message-ID <lvsn3f$72u$1@online.de> (permalink)
References (12 earlier) <v4udnX81PYIQOmTOnZ2dnUU7-UmdnZ2d@supernews.com> <2014Aug24.153654@mips.complang.tuwien.ac.at> <8_GdncRAvdZ7Y2fOnZ2dnUU7-cednZ2d@supernews.com> <lvs348$u8j$1@online.de> <Qvudnabjdu5jArzJnZ2dnUU7-b9i4p2d@supernews.com>

Show all headers | View raw


Andrew Haley wrote:

> Bernd Paysan <bernd.paysan@gmx.de> wrote:
>> Andrew Haley wrote:
>> 
>>> I stand by my claim.  [COMPILE] is intended for immediate words, and
>>> using it on non-immediate words is useless or worse.  Usually worse.
>> 
>> Actually, the way the standard specifies [COMPILE] is quite different. 
>> The
>> problem here IMHO is the standard.  We should take a closer look at
>> [COMPILE] in the next two days, it is certainly specified in a way which
>> nobody implements.  We all implement the [COMPILE] which makes immediate
>> words non-immediate.  The implication of the standard text is that the
>> semantics maps 1:1 to immediacy and compile-only flags in Forth-83, and
>> this can't be what has been intended.
> 
> Isn't [COMPILE] obsolescent anyway?  Can't it now be deleted?

No, it's not.  There's no mentioning of obsolescence anywhere.  It just has 
no interpretation semantics, and the compilation semantics is defined as:

Compilation: Skip leading space delimiters. Parse name delimited by a space. 
Find name. If name has other than default compilation semantics, append them 
to the current definition; otherwise append the execution semantics of name. 
An ambiguous condition exists if name is not found.

IMHO the action described in sentence 4 is wrong in all possible ways.  In a 
traditional system, "append the execution semantics of name" would be right, 
the other part is not necessary (traditionally, non-default compilation 
semantics is achieved by being immediate, which means that it's the 
execution semantics).

Note that there has been a paragraph about [COMPILE] in the compatibility 
section of Forth 94:

"Impact: [COMPILE] remains in ANS Forth, since its proper use does not 
depend on knowledge of whether or not a word is immediate (Use of [COMPILE] 
with a non-immediate word is and has always been a no-op). Whether or not 
you need to use [COMPILE] requires knowledge of whether or not its target 
word is immediate, but it is always safe to use [COMPILE]. [COMPILE] is no 
longer in the (required) core word set, having been moved to the Core 
Extensions word set, but the committee anticipates that most vendors will 
supply it anyway."

This is 50% bullshit, and the other 50% assumes that [COMPILE] simply 
ignores the immediacy flag.  It's not "always safe to use [COMPILE]", since 
it either alters the behavior to non-immediacy, or it does nothing, 
depending on the immediacy of the word it is applied to.

In effect, we should change the spec of [COMPILE] to that, i.e. that it 
simply is an one-shot interpreter that ignores the immediacy flag, and that 
you can only apply [COMPILE] savely on your own words (where you know if 
they are immediate or not), and mark it as obsolescent.  Reference 
implementation:

: [compile] ( "name" -- ) ' compile, ; immediate

For systems like Gforth, where we make the promise that traditional stuff 
will quite often work, it means that EXIT and LEAVE will have to be non-
immediate; that's something we can do in Gforth git.

I'd actually put it a bit stronger: The expectation for a system that allows 
traditional stuff is that this reference implementation just works.  But a 
standard program should not expect that every system works like this.

-- 
Bernd Paysan
"If you want it done right, you have to do it yourself"
http://bernd-paysan.de/

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


Thread

does VFX have the same bug as Gforth? hughaguilar96@yahoo.com - 2014-08-17 21:09 -0700
  Re: does VFX have the same bug as Gforth? Bee <forth@calcentral.com> - 2014-08-17 23:06 -0700
    Re: does VFX have the same bug as Gforth? hughaguilar96@yahoo.com - 2014-08-18 17:03 -0700
      Re: does VFX have the same bug as Gforth? "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-08-18 22:19 -0400
      Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-19 09:14 +0000
        Re: does VFX have the same bug as Gforth? Bernd Paysan <bernd.paysan@gmx.de> - 2014-08-19 15:23 +0200
          Re: does VFX have the same bug as Gforth? "Alex McDonald" <blog@rivadpm.com> - 2014-08-19 14:54 +0100
            Re: does VFX have the same bug as Gforth? Bernd Paysan <bernd.paysan@gmx.de> - 2014-08-19 16:09 +0200
              Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-19 15:39 +0000
                Re: does VFX have the same bug as Gforth? Bernd Paysan <bernd.paysan@gmx.de> - 2014-08-19 22:34 +0200
                Re: does VFX have the same bug as Gforth? "Alex McDonald" <blog@rivadpm.com> - 2014-08-19 23:29 +0100
                Re: does VFX have the same bug as Gforth? Bernd Paysan <bernd.paysan@gmx.de> - 2014-08-20 23:06 +0200
                Re: does VFX have the same bug as Gforth? "Alex McDonald" <blog@rivadpm.com> - 2014-08-20 22:21 +0100
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-20 07:46 +0000
                Re: does VFX have the same bug as Gforth? Bernd Paysan <bernd.paysan@gmx.de> - 2014-08-21 00:26 +0200
                Re: does VFX have the same bug as Gforth? hughaguilar96@yahoo.com - 2014-08-20 22:42 -0700
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-21 10:23 +0000
                Re: does VFX have the same bug as Gforth? hughaguilar96@yahoo.com - 2014-08-21 23:29 -0700
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-22 12:54 +0000
                Re: does VFX have the same bug as Gforth? hughaguilar96@yahoo.com - 2014-08-22 17:54 -0700
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-23 10:46 +0000
                Re: does VFX have the same bug as Gforth? hughaguilar96@yahoo.com - 2014-08-23 11:15 -0700
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-24 13:32 +0000
                Re: does VFX have the same bug as Gforth? hughaguilar96@yahoo.com - 2014-08-24 10:40 -0700
                Re: does VFX have the same bug as Gforth? Bee <forth@calcentral.com> - 2014-08-24 22:03 -0700
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-25 08:31 +0000
                Re: does VFX have the same bug as Gforth? hughaguilar96@yahoo.com - 2014-08-25 22:55 -0700
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-21 12:45 +0000
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-22 15:13 +0000
                Re: does VFX have the same bug as Gforth? Bernd Paysan <bernd.paysan@gmx.de> - 2014-08-22 18:47 +0200
                Re: does VFX have the same bug as Gforth? hughaguilar96@yahoo.com - 2014-08-22 18:28 -0700
                Re: does VFX have the same bug as Gforth? "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-08-23 04:44 -0400
                Re: does VFX have the same bug as Gforth? Coos Haak <chforth@hccnet.nl> - 2014-08-23 16:15 +0200
                Re: does VFX have the same bug as Gforth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-23 11:50 -0500
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-23 07:15 +0000
                Re: does VFX have the same bug as Gforth? Bernd Paysan <bernd.paysan@gmx.de> - 2014-08-23 22:12 +0200
                Re: does VFX have the same bug as Gforth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-24 03:51 -0500
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-24 13:36 +0000
                Re: does VFX have the same bug as Gforth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-25 04:16 -0500
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-25 09:44 +0000
                Re: does VFX have the same bug as Gforth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-25 11:53 -0500
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-26 06:34 +0000
                Re: does VFX have the same bug as Gforth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-26 03:55 -0500
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-26 12:37 +0000
                Re: does VFX have the same bug as Gforth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-26 08:24 -0500
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-26 13:55 +0000
                Re: does VFX have the same bug as Gforth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-26 10:42 -0500
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-26 16:05 +0000
                Re: does VFX have the same bug as Gforth? Bernd Paysan <bernd.paysan@gmx.de> - 2014-09-23 17:20 +0200
                Re: does VFX have the same bug as Gforth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-09-23 11:29 -0500
                Re: does VFX have the same bug as Gforth? Bernd Paysan <bernd.paysan@gmx.de> - 2014-09-23 23:01 +0200
                Re: does VFX have the same bug as Gforth? albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-08-25 15:59 +0000
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-26 06:23 +0000
                Re: does VFX have the same bug as Gforth? albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-08-26 09:15 +0000
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-26 13:23 +0000
                Re: does VFX have the same bug as Gforth? Mark Wills <markwills1970@gmail.com> - 2014-08-26 01:41 -0700
                Re: does VFX have the same bug as Gforth? albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-08-26 09:32 +0000
                Re: does VFX have the same bug as Gforth? albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-08-26 09:43 +0000
                Re: does VFX have the same bug as Gforth? Mark Wills <markwills1970@gmail.com> - 2014-08-26 02:48 -0700
                Re: does VFX have the same bug as Gforth? albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-08-26 11:58 +0000
                Re: does VFX have the same bug as Gforth? Mark Wills <markwills1970@gmail.com> - 2014-08-26 05:20 -0700
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-26 12:30 +0000
                Re: does VFX have the same bug as Gforth? stephenXXX@mpeforth.com (Stephen Pelc) - 2014-08-25 14:15 +0000
                Re: does VFX have the same bug as Gforth? Mark Wills <markwills1970@gmail.com> - 2014-08-25 07:44 -0700
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-25 14:37 +0000
                Re: does VFX have the same bug as Gforth? stephenXXX@mpeforth.com (Stephen Pelc) - 2014-08-25 15:14 +0000
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-25 15:33 +0000
                Re: does VFX have the same bug as Gforth? Mark Wills <markwills1970@gmail.com> - 2014-08-26 01:56 -0700
                Re: does VFX have the same bug as Gforth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-26 04:16 -0500
                Re: does VFX have the same bug as Gforth? Mark Wills <markwills1970@gmail.com> - 2014-08-26 02:24 -0700
                Re: does VFX have the same bug as Gforth? albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-08-26 09:36 +0000
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-26 13:40 +0000
                Re: does VFX have the same bug as Gforth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-26 08:57 -0500
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-26 12:52 +0000
                Re: does VFX have the same bug as Gforth? stephenXXX@mpeforth.com (Stephen Pelc) - 2014-08-26 14:14 +0000
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-26 14:36 +0000
                Re: does VFX have the same bug as Gforth? Bernd Paysan <bernd.paysan@gmx.de> - 2014-09-23 17:40 +0200
                Re: does VFX have the same bug as Gforth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-26 10:53 -0500
                Re: does VFX have the same bug as Gforth? Bernd Paysan <bernd.paysan@gmx.de> - 2014-09-23 17:36 +0200
                Re: does VFX have the same bug as Gforth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-25 12:02 -0500
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-26 06:42 +0000
                Re: does VFX have the same bug as Gforth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-26 04:08 -0500
                Re: does VFX have the same bug as Gforth? stephenXXX@mpeforth.com (Stephen Pelc) - 2014-08-26 10:37 +0000
                Re: does VFX have the same bug as Gforth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-26 08:30 -0500
                Re: does VFX have the same bug as Gforth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-28 08:47 -0500
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-29 13:03 +0000
                Re: does VFX have the same bug as Gforth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-08-29 09:16 -0500
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-26 13:06 +0000
                Re: does VFX have the same bug as Gforth? "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-08-26 07:36 -0400
                Re: does VFX have the same bug as Gforth? Bernd Paysan <bernd.paysan@gmx.de> - 2014-09-23 17:28 +0200
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-24 09:48 +0000
                Re: does VFX have the same bug as Gforth? "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-08-24 15:55 -0400
                Re: does VFX have the same bug as Gforth? "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-08-24 15:55 -0400
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-25 08:26 +0000
                Re: does VFX have the same bug as Gforth? "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-08-26 07:36 -0400
                Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-26 12:12 +0000
                Re: does VFX have the same bug as Gforth? Bernd Paysan <bernd.paysan@gmx.de> - 2014-09-23 17:45 +0200
                Re: does VFX have the same bug as Gforth? Mark Wills <markwills1970@gmail.com> - 2014-08-21 03:25 -0700
                Re: does VFX have the same bug as Gforth? hughaguilar96@yahoo.com - 2014-08-21 23:14 -0700
            Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-19 14:16 +0000
  Re: does VFX have the same bug as Gforth? Bee <forth@calcentral.com> - 2014-08-17 23:16 -0700
    Re: does VFX have the same bug as Gforth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-08-19 09:40 +0000
  Re: does VFX have the same bug as Gforth? Paul E Bennett <Paul_E.Bennett@topmail.co.uk> - 2014-08-18 09:16 +0100
  Re: does VFX have the same bug as Gforth? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-08-18 09:32 +0100
    Re: does VFX have the same bug as Gforth? "Alex McDonald" <blog@rivadpm.com> - 2014-08-18 13:09 +0100
  Re: does VFX have the same bug as Gforth? stephenXXX@mpeforth.com (Stephen Pelc) - 2014-08-18 12:29 +0000
    Re: does VFX have the same bug as Gforth? hughaguilar96@yahoo.com - 2014-08-18 17:10 -0700
      Re: does VFX have the same bug as Gforth? Bee <forth@calcentral.com> - 2014-08-18 17:48 -0700
        Re: does VFX have the same bug as Gforth? hughaguilar96@yahoo.com - 2014-08-18 18:23 -0700
      Re: does VFX have the same bug as Gforth? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-08-19 13:55 +0100

csiph-web