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Groups > comp.lang.forth > #50560
| From | anton@mips.complang.tuwien.ac.at (Anton Ertl) |
|---|---|
| Newsgroups | comp.lang.forth |
| Subject | Re: Rosetta Code: Catamorphism |
| Date | 2016-08-29 20:53 +0000 |
| Organization | Institut fuer Computersprachen, Technische Universitaet Wien |
| Message-ID | <2016Aug29.225348@mips.complang.tuwien.ac.at> (permalink) |
| References | (4 earlier) <836dda04-3aea-4e2f-83b1-574930d88525@googlegroups.com> <2c7a5c2a-ff8b-42fc-86cf-41887efce07a@googlegroups.com> <cbdcd712-4fc3-4aa5-b647-221e43fc12a5@googlegroups.com> <2016Aug29.185823@mips.complang.tuwien.ac.at> <2fd53f27-16d9-431c-bf39-ec16c6be9f38@googlegroups.com> |
peter.m.falth@gmail.com writes:
>On Monday, 29 August 2016 19:24:46 UTC+2, Anton Ertl wrote:
>> As for why the direction of
>>=20
>> ]]...[[
>>=20
>> is in this direction: It's because
>>=20
>> ] ... [
>>=20
>> switches from interpretation to compilation and back; likewise, ]]
>> switches from compilation to postponing and [[ switches back.
>=20
>This is why I think you got it backwards. I see it as
>[ switches from compilation to interpretation and ] back to compiling
>
>therefore=20
>
>[[ should switch from compilation to postponing and ]] back to compiling
>=20
If you see it as different things, and compilation as the normal mode,
you have a point.
The basic idea behind ]]...[[ is that ] switches to the next more
delaying state (from interpretation to compilation, from compilation
to postponing), and [ to the next less delaying state (from postponing
to compiling, from compiling to interpreting); however, unfortunately,
the standard specifies "]" in a way that does not allow working the
way envisioned above, so "]]" was introduced instead, and "[[" to go
with it. And the current implementation only do the switching from
compilation to postponing, and back, not the full monty.
It may be more obvious why the brackets have this direction, if you
want to have some intermediate compilation action in the middle of the
postponeing, e.g.:
: derivative { xt1 F: r -- xt2 }
:noname ]]
fdup [[ r ]] fliteral f+ [[ xt1 compile, ]] fswap [[ xt1 compile, ]] f-
[[ r ]] fliteral f/ ;
[[ ;
>it really looks backwards now!
Looking at the DERIVATIVE example, do you still think so?
>or it could be post[ ... ]pone for extra clarity
Or use that for DERIVATIVE?
- 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
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Rosetta Code: Catamorphism "WJ" <w_a_x_man@yahoo.com> - 2016-08-24 15:27 +0000
Rosetta Code: Catamorphism Julian Fondren <julian.fondren@gmail.com> - 2016-08-24 12:43 -0700
Re: Rosetta Code: Catamorphism anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-08-25 09:53 +0000
Re: Rosetta Code: Catamorphism Julian Fondren <julian.fondren@gmail.com> - 2016-08-25 06:41 -0700
Re: Rosetta Code: Catamorphism Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-08-25 16:06 -0500
Re: Rosetta Code: Catamorphism foxaudioresearch@gmail.com - 2016-08-25 20:40 -0700
Rosetta Code ( was Re: Rosetta Code: Catamorphism) "HAA" <someone@microsoft.com> - 2016-08-29 12:06 +1000
Re: Rosetta Code ( was Re: Rosetta Code: Catamorphism) Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-08-29 01:41 -0500
Re: Rosetta Code: Catamorphism anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-08-27 10:01 +0000
Re: Rosetta Code: Catamorphism hughaguilar96@gmail.com - 2016-08-29 01:21 -0700
Re: Rosetta Code: Catamorphism hughaguilar96@gmail.com - 2016-08-29 01:36 -0700
Re: Rosetta Code: Catamorphism Julian Fondren <ayrnieu@gmail.com> - 2016-08-29 07:23 -0700
Re: Rosetta Code: Catamorphism anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-08-29 16:58 +0000
Re: Rosetta Code: Catamorphism peter.m.falth@gmail.com - 2016-08-29 13:15 -0700
Re: Rosetta Code: Catamorphism anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-08-29 20:53 +0000
Re: Rosetta Code: Catamorphism peter.m.falth@gmail.com - 2016-08-30 04:47 -0700
Re: Rosetta Code: Catamorphism anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-09-05 07:13 +0000
Re: Rosetta Code: Catamorphism "HAA" <someone@microsoft.com> - 2016-08-30 11:54 +1000
Re: Rosetta Code: Catamorphism "HAA" <someone@microsoft.com> - 2016-08-31 12:34 +1000
Re: Rosetta Code: Catamorphism "HAA" <someone@microsoft.com> - 2016-08-29 18:44 +1000
Re: Rosetta Code: Catamorphism hughaguilar96@gmail.com - 2016-09-01 23:47 -0700
Re: Rosetta Code: Catamorphism Coos Haak <htrofhc@gmail.com> - 2016-09-02 12:42 +0200
Re: Rosetta Code: Catamorphism anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-09-02 11:45 +0000
Re: Rosetta Code: Catamorphism Coos Haak <htrofhc@gmail.com> - 2016-09-02 15:01 +0200
Re: Rosetta Code: Catamorphism anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-09-02 16:04 +0000
Re: Rosetta Code: Catamorphism albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-09-02 16:23 +0200
Re: Rosetta Code: Catamorphism Bruce Axtens <bruce.axtens@gmail.com> - 2016-08-29 18:29 +0800
Re: Rosetta Code: Catamorphism Ron Aaron <rambamist@gmail.com> - 2016-08-29 13:41 +0300
Re: Rosetta Code: Catamorphism Bruce Axtens <bruce.axtens@gmail.com> - 2016-08-31 09:24 +0800
Standard or Forth? "HAA" <someone@microsoft.com> - 2016-09-01 13:45 +1000
Re: Standard or Forth? hughaguilar96@gmail.com - 2016-09-02 21:54 -0700
Re: Standard or Forth? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2016-09-04 07:35 +0100
Re: Standard or Forth? hughaguilar96@gmail.com - 2016-09-04 00:41 -0700
Re: Standard or Forth? Julian Fondren <julian.fondren@gmail.com> - 2016-09-04 02:55 -0700
Re: Standard or Forth? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2016-09-04 13:26 +0100
Re: Standard or Forth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-09-04 13:59 +0000
Re: Standard or Forth? hughaguilar96@gmail.com - 2016-09-04 23:09 -0700
Re: Standard or Forth? Ron Aaron <rambamist@gmail.com> - 2016-09-05 09:55 +0300
Re: Standard or Forth? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2016-09-05 08:39 +0100
Re: Standard or Forth? hughaguilar96@gmail.com - 2016-09-04 01:25 -0700
Re: Standard or Forth? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2016-09-04 14:13 +0100
Re: Standard or Forth? Coos Haak <htrofhc@gmail.com> - 2016-09-04 23:16 +0200
Re: Standard or Forth? hughaguilar96@gmail.com - 2016-09-04 22:33 -0700
Re: Standard or Forth? Ron Aaron <rambamist@gmail.com> - 2016-09-05 09:03 +0300
Re: Standard or Forth? hughaguilar96@gmail.com - 2016-09-06 23:23 -0700
Re: Standard or Forth? Ron Aaron <rambamist@gmail.com> - 2016-09-07 10:14 +0300
Re: Standard or Forth? hughaguilar96@gmail.com - 2016-09-07 01:01 -0700
Re: Standard or Forth? Ron Aaron <rambamist@gmail.com> - 2016-09-07 11:18 +0300
Re: Standard or Forth? Cecil Bayona <cbayona@cbayona.com> - 2016-09-07 08:47 -0500
Re: Standard or Forth? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2016-09-05 09:20 +0100
Re: Standard or Forth? hughaguilar96@gmail.com - 2016-09-05 02:21 -0700
Re: Standard or Forth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-09-05 08:10 +0000
Re: Standard or Forth? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2016-09-05 10:51 +0100
Re: Standard or Forth? "Elizabeth D. Rather" <erather@forth.com> - 2016-09-03 08:05 +0200
Re: Standard or Forth? Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-09-03 03:00 -0500
Re: Standard or Forth? "HAA" <someone@microsoft.com> - 2016-09-03 22:48 +1000
Re: Standard or Forth? Alex <alex@rivadpm.com> - 2016-09-03 15:05 +0100
Re: Standard or Forth? Julian Fondren <julian.fondren@gmail.com> - 2016-09-03 07:46 -0700
Re: Standard or Forth? "Elizabeth D. Rather" <erather@forth.com> - 2016-09-03 23:53 +0200
Re: Standard or Forth? stephen@mpeforth.com (Stephen Pelc) - 2016-09-03 22:37 +0000
Re: Standard or Forth? hughaguilar96@gmail.com - 2016-09-03 21:17 -0700
Re: Standard or Forth? "HAA" <someone@microsoft.com> - 2016-09-05 02:35 +1000
Re: Standard or Forth? albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-09-05 03:18 +0200
Re: Standard or Forth? "HAA" <someone@microsoft.com> - 2016-09-08 22:04 +1000
Re: Standard or Forth? Paul Rubin <no.email@nospam.invalid> - 2016-09-08 12:41 -0700
Re: Standard or Forth? "HAA" <someone@microsoft.com> - 2016-09-09 12:51 +1000
Re: Standard or Forth? Paul Rubin <no.email@nospam.invalid> - 2016-09-08 21:50 -0700
Re: Standard or Forth? "HAA" <someone@microsoft.com> - 2016-09-12 17:16 +1000
Re: Standard or Forth? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-09-12 16:59 +0000
Re: Standard or Forth? "HAA" <someone@microsoft.com> - 2016-09-15 13:38 +1000
Re: Standard or Forth? hughaguilar96@gmail.com - 2016-09-08 23:33 -0700
Re: Standard or Forth? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2016-09-05 08:41 +0100
Re: Standard or Forth? hughaguilar96@gmail.com - 2016-09-05 01:42 -0700
Re: Rosetta Code: Catamorphism albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2016-08-29 16:03 +0200
Re: Rosetta Code: Catamorphism anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-08-29 16:04 +0000
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