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Groups > comp.lang.forth > #43735
| From | Gerry Jackson <gerry@jackson9000.fsnet.co.uk> |
|---|---|
| Newsgroups | comp.lang.forth |
| Subject | Re: POSTPONE behaviour |
| Date | 2015-11-25 07:39 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <n33ofa$u7g$1@dont-email.me> (permalink) |
| References | <49eeaf16-5bdf-449c-8278-59e2bb992441@googlegroups.com> <b4792de6-8408-4e0c-8d9d-ddc9558500ef@googlegroups.com> <7f06c60a-bc63-4aa3-adfc-877972fa9120@googlegroups.com> <98a20b8e-3531-4d97-9fbb-f16216edca0d@googlegroups.com> |
On 25/11/2015 06:54, Raimond Dragomir wrote:
>> But failing in this case:
>> T{ : GT1 123 ; -> }T
>> T{ : GT4 POSTPONE GT1 ; IMMEDIATE -> }T
>> T{ : GT5 GT4 ; -> }T
>> T{ GT5 -> 123 }T
>
> Well, think about it: GT4 is immediate. It is executed directly when you
> define GT5. When executed it will call GT1 which leaves 123 on the data stack.
>
> So you already have 123 on the stack after GT5 definition.
> Also, GT5 body is just a nop, because you compiled nothing (GT4 just
> executed at compile time).
> So when you lastly execute GT5 it will leave nothing (but you expect 123)
>
> Hope it helps
>
No, you're wrong. If you try it in GForth
: GT1 123 ; ok
: GT4 POSTPONE GT1 ; IMMEDIATE ok
: GT5 GT4 ; ok
gt5 . 123 ok
see gt5
: GT5
GT1 ; ok
GT4 compiles GT1 into the definition of GT5
From your other post:
> If the word postponed is not immediate, then postpone is redundant.
> .... FOO ... and
> .... POSTPONE FOO ... is the same thing if the FOO is not immediate.
is wrong too, POSTPONE is used for macros e.g.
: RDROP POSTPONE R> POSTPONE DROP ;
: FOO RDROP ; ok
see RDROP
: RDROP [']
r> >comp ['] drop >comp ; immediate ok
see FOO
: FOO
r> drop ; ok
Read the ANS spec for POSTPONE carefully
--
Gerry
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POSTPONE behaviour Aliaksei Chapyzhenka <alex.drom@gmail.com> - 2015-11-24 21:18 -0800
Re: POSTPONE behaviour Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-11-24 22:00 -0800
Re: POSTPONE behaviour Aliaksei Chapyzhenka <alex.drom@gmail.com> - 2015-11-24 22:15 -0800
Re: POSTPONE behaviour Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-11-24 22:54 -0800
Re: POSTPONE behaviour Aliaksei Chapyzhenka <alex.drom@gmail.com> - 2015-11-24 23:09 -0800
Re: POSTPONE behaviour Lars Brinkhoff <lars.spam@nocrew.org> - 2015-11-25 08:15 +0100
Re: POSTPONE behaviour Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-11-24 23:38 -0800
Re: POSTPONE behaviour Lars Brinkhoff <lars.spam@nocrew.org> - 2015-11-25 08:46 +0100
Re: POSTPONE behaviour Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-11-25 00:04 -0800
Re: POSTPONE behaviour rickman <gnuarm@gmail.com> - 2015-11-25 03:01 -0500
Re: POSTPONE behaviour Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-11-25 00:09 -0800
Re: POSTPONE behaviour rickman <gnuarm@gmail.com> - 2015-11-25 03:23 -0500
Re: POSTPONE behaviour Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-11-25 01:09 -0800
Re: POSTPONE behaviour rickman <gnuarm@gmail.com> - 2015-11-25 10:49 -0500
Re: POSTPONE behaviour "Elizabeth D. Rather" <erather@forth.com> - 2015-11-25 09:10 -1000
Re: POSTPONE behaviour Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-11-25 09:18 +0000
Re: POSTPONE behaviour Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-11-25 02:21 -0800
Re: POSTPONE behaviour Mark Wills <markwills1970@gmail.com> - 2015-11-25 02:47 -0800
Re: POSTPONE behaviour Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-11-25 13:58 +0000
Re: POSTPONE behaviour Mark Wills <markwills1970@gmail.com> - 2015-11-25 06:35 -0800
Re: POSTPONE behaviour Bernd Paysan <bernd.paysan@gmx.de> - 2015-11-25 18:45 +0100
Re: POSTPONE behaviour Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-11-25 22:11 -0800
Re: POSTPONE behaviour Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-11-26 07:42 +0000
Re: POSTPONE behaviour "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-11-26 05:20 -0500
Re: POSTPONE behaviour anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-11-26 16:50 +0000
Re: POSTPONE behaviour Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-11-26 17:59 +0000
Re: POSTPONE behaviour Bernd Paysan <bernd.paysan@gmx.de> - 2015-11-27 19:07 +0100
Re: POSTPONE behaviour anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-11-28 11:24 +0000
Re: POSTPONE behaviour hughaguilar96@gmail.com - 2015-11-26 12:29 -0800
Re: POSTPONE behaviour Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-11-27 09:53 +0000
Re: POSTPONE behaviour hughaguilar96@gmail.com - 2015-11-29 21:48 -0800
Re: POSTPONE behaviour Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-11-30 12:18 +0000
Re: POSTPONE behaviour Lars Brinkhoff <lars.spam@nocrew.org> - 2015-11-30 13:41 +0100
Re: POSTPONE behaviour hughaguilar96@gmail.com - 2015-11-30 19:56 -0800
Re: POSTPONE behaviour Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-12-01 09:59 +0000
Re: POSTPONE behaviour hughaguilar96@gmail.com - 2015-12-01 22:46 -0800
Re: POSTPONE behaviour Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-12-02 07:50 +0000
Re: POSTPONE behaviour anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-11-25 13:45 +0000
Re: POSTPONE behaviour rickman <gnuarm@gmail.com> - 2015-11-25 10:54 -0500
Re: POSTPONE behaviour Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-11-25 07:39 +0000
Re: POSTPONE behaviour Aliaksei Chapyzhenka <alex.drom@gmail.com> - 2015-11-24 23:48 -0800
Re: POSTPONE behaviour Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-11-25 08:03 +0000
Re: POSTPONE behaviour Bernd Paysan <bernd.paysan@gmx.de> - 2015-11-25 18:37 +0100
Re: POSTPONE behaviour "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-11-25 01:27 -0500
Re: POSTPONE behaviour Aliaksei Chapyzhenka <alex.drom@gmail.com> - 2015-11-24 22:51 -0800
Re: POSTPONE behaviour Aliaksei Chapyzhenka <alex.drom@gmail.com> - 2015-11-25 21:19 -0800
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