Re: Quotations revisited

From	Aleksej Saushev <asau@inbox.ru>
Newsgroups	comp.lang.forth
Subject	Re: Quotations revisited
Date	2012-07-23 03:29 +0400
Organization	A noiseless patient Spider
Message-ID	<87vchfml2c.fsf@inbox.ru> (permalink)
References	(13 earlier) <cpydnX_9HJlBjJfNnZ2dnUVZ_vednZ2d@supernews.com> <30fdf529-6c73-49d7-8fdc-f02271e33ebc@g5g2000yqg.googlegroups.com> <--idnS0grfwsMZbNnZ2dnUVZ_qednZ2d@supernews.com> <871uk3r9vk.fsf@inbox.ru> <7vydnY5PU6bD3pHNnZ2dnUVZ_sSdnZ2d@supernews.com>

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"Elizabeth D. Rather" <erather@forth.com> writes:

> On 7/22/12 7:19 AM, Aleksej Saushev wrote:
>> "Elizabeth D. Rather" <erather@forth.com> writes:
>>
>>> On 7/21/12 12:59 AM, Alex McDonald wrote:
>>>> On Jul 21, 3:20 am, "Elizabeth D. Rather" <erat...@forth.com> wrote:
>>>>> On 7/20/12 11:24 AM, Aleksej Saushev wrote:
>>> ...
>>>>>>> Most implementations of DUMP I know of are interruptible but not
>>>>>>> by trapping H. A more appropriate strategy is with a KEY? in the
>>>>>>> loop, maybe once/line. Likewise anything else capable of
>>>>>>> generating a lot of output.
>>>>>
>>>>>> Do you mean that there're no other ways to interrupt program than by
>>>>>> writing it so that it constantly polls for some event?
>>>>>
>>>>> It's the cleanest to implement and has fewest side-effects. The cost of
>>>>> a KEY? per line out output is pretty minimal, a lot less than a CATCH
>>>>> around every H.
>>>>
>>>> In many hosted Forths, the executed instruction cost of KEY? per line
>>>> will be much higher than a CATCH per H.; a call to the OS, context
>>>> switching and stream management at the cost of several thousand
>>>> instructions per KEY? is not minimal.
>>>
>>> In my experience, a keystroke is captured by an interrupt which
>>> records the keyboard event. It does not take either an I/O
>>> operation nor an OS call to inquire whether an event has
>>> occurred, merely a check of a memory location. Thereupon code
>>> can obtain the key if it cares, but often you're just interested
>>> in the existence of the event. Very cheap.
>>
>> Not at all! You have to write the polling code everywhere you know
>> it can be interrupted. You need to track all those places too.
>> With "catch" you write all that code only once. Now compare the price.
>
> No, a keyboard interrupt handler is a single instance of code
> that responds to an event. It doesn't poll.

You have to check the result of this in any place where user (not you!)
might interrupt the program. That is you have to poll it constantly.
This is way more overhead than putting single "catch" around the top level.

> And putting CATCH around something as tiny as H. implies you
> have to sprinkle them in every word that does output.  Ugh.

No, it doesn't. If you have read my example, you have seen that it
implies exactly the opposite: when I need to put single "catch" around
top level word, you have to sprinkle your "key? if ... then" everywhere.
Otherwise your code has to run till the end of lengthy loop only to
find out that user asked to interrupt it perhaps several hours ago.


-- 
HE CE3OH...

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Quotations revisited mhx@iae.nl (Marcel Hendrix) - 2012-07-14 15:55 +0200
  Re: Quotations revisited stephenXXX@mpeforth.com (Stephen Pelc) - 2012-07-15 19:26 +0000
    Re: Quotations revisited Bernd Paysan <bernd.paysan@gmx.de> - 2012-07-15 23:53 +0200
    Re: Quotations revisited mhx@iae.nl (Marcel Hendrix) - 2012-07-15 23:54 +0200
      Re: Quotations revisited Bernd Paysan <bernd.paysan@gmx.de> - 2012-07-16 00:48 +0200
        Re: Quotations revisited Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-22 15:01 +0000
          Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-23 16:49 +0000
            Re: Quotations revisited Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-23 21:39 +0000
              Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-25 13:13 +0000
        Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-22 11:07 -0500
          Re: Quotations revisited Paul Rubin <no.email@nospam.invalid> - 2012-07-22 10:21 -0700
            Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-22 12:35 -0500
              Re: Quotations revisited Paul Rubin <no.email@nospam.invalid> - 2012-07-22 11:39 -0700
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-22 15:16 -0500
                Re: Quotations revisited Paul Rubin <no.email@nospam.invalid> - 2012-07-22 14:35 -0700
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-23 04:18 -0500
                Re: Quotations revisited Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-23 12:58 +0000
                Re: Quotations revisited Paul Rubin <no.email@nospam.invalid> - 2012-07-23 11:55 -0700
                Re: Quotations revisited BruceMcF <agila61@netscape.net> - 2012-07-23 05:45 -0700
            Re: Quotations revisited Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-27 12:41 +0000
      Re: Quotations revisited "Elizabeth D. Rather" <erather@forth.com> - 2012-07-15 14:11 -1000
        Re: Quotations revisited "A. K." <akk@nospam.org> - 2012-07-16 07:47 +0200
          Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-16 13:56 +0000
            Re: Quotations revisited "Elizabeth D. Rather" <erather@forth.com> - 2012-07-16 07:20 -1000
              Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-17 13:49 +0000
        Re: Quotations revisited Mark Wills <markrobertwills@yahoo.co.uk> - 2012-07-16 02:32 -0700
          Re: Quotations revisited Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-27 12:58 +0000
        Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-16 04:32 -0500
          Re: Quotations revisited stephenXXX@mpeforth.com (Stephen Pelc) - 2012-07-16 11:41 +0000
            Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-16 07:40 -0500
              Re: Quotations revisited stephenXXX@mpeforth.com (Stephen Pelc) - 2012-07-16 14:05 +0000
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-16 09:20 -0500
                Re: Quotations revisited stephenXXX@mpeforth.com (Stephen Pelc) - 2012-07-16 15:46 +0000
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-16 11:33 -0500
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-16 15:32 +0000
                Re: Quotations revisited stephenXXX@mpeforth.com (Stephen Pelc) - 2012-07-16 17:56 +0000
                Re: Quotations revisited Bernd Paysan <bernd.paysan@gmx.de> - 2012-07-16 23:37 +0200
          Re: Quotations revisited Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-27 13:05 +0000
            Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-27 08:21 -0500
      Re: Quotations revisited Roelf Toxopeus <rt4all@notthis.hetnet.nl> - 2012-07-16 10:14 +0200
      Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-16 04:23 -0500
        Re: Quotations revisited m.a.m.hendrix@tue.nl - 2012-07-16 03:39 -0700
          Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-16 07:09 -0500
            Re: Quotations revisited mhx@iae.nl (Marcel Hendrix) - 2012-07-16 23:47 +0200
              Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-17 04:14 -0500
                Re: Quotations revisited Coos Haak <chforth@hccnet.nl> - 2012-07-17 17:39 +0200
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-17 12:18 -0500
                Re: Quotations revisited mhx@iae.nl (Marcel Hendrix) - 2012-07-17 20:26 +0200
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-19 16:21 +0000
                Re: Quotations revisited Alex McDonald <blog@rivadpm.com> - 2012-07-19 15:58 -0700
      Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-16 14:05 +0000
    Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-16 12:47 +0000
      Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-16 08:56 -0500
      Re: Quotations revisited Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2012-07-16 15:04 +0100
        Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-16 09:23 -0500
          Re: Quotations revisited Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2012-07-16 17:38 +0100
            Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-16 12:58 -0500
        Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-16 14:56 +0000
      Re: Quotations revisited Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-16 22:53 +0000
        Re: Quotations revisited BruceMcF <agila61@netscape.net> - 2012-07-16 19:59 -0700
          Re: Quotations revisited "Elizabeth D. Rather" <erather@forth.com> - 2012-07-16 17:04 -1000
            Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-17 06:51 +0000
              Re: Quotations revisited "Elizabeth D. Rather" <erather@forth.com> - 2012-07-16 21:39 -1000
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-17 07:48 +0000
                Re: Quotations revisited "Elizabeth D. Rather" <erather@forth.com> - 2012-07-16 22:24 -1000
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-17 10:48 +0000
                Re: Quotations revisited "Elizabeth D. Rather" <erather@forth.com> - 2012-07-17 08:19 -1000
                Re: Quotations revisited Aleksej Saushev <asau@inbox.ru> - 2012-07-18 01:31 +0400
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-19 16:11 +0000
                Re: Quotations revisited "Elizabeth D. Rather" <erather@forth.com> - 2012-07-19 12:41 -1000
                Re: Quotations revisited Aleksej Saushev <asau@inbox.ru> - 2012-07-21 01:24 +0400
                Re: Quotations revisited "Elizabeth D. Rather" <erather@forth.com> - 2012-07-20 16:20 -1000
                Re: Quotations revisited Alex McDonald <blog@rivadpm.com> - 2012-07-21 03:59 -0700
                Re: Quotations revisited "Elizabeth D. Rather" <erather@forth.com> - 2012-07-21 21:33 -1000
                Re: Quotations revisited Alex McDonald <blog@rivadpm.com> - 2012-07-22 01:35 -0700
                Re: Quotations revisited Aleksej Saushev <asau@inbox.ru> - 2012-07-22 21:19 +0400
                Re: Quotations revisited "Elizabeth D. Rather" <erather@forth.com> - 2012-07-22 08:15 -1000
                Re: Quotations revisited Paul Rubin <no.email@nospam.invalid> - 2012-07-22 11:48 -0700
                Re: Quotations revisited Coos Haak <chforth@hccnet.nl> - 2012-07-22 21:48 +0200
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-22 15:22 -0500
                Re: Quotations revisited Paul Rubin <no.email@nospam.invalid> - 2012-07-22 14:50 -0700
                Re: Quotations revisited Paul Rubin <no.email@nospam.invalid> - 2012-07-22 15:08 -0700
                Re: Quotations revisited Alex McDonald <blog@rivadpm.com> - 2012-07-22 15:20 -0700
                Re: Quotations revisited Aleksej Saushev <asau@inbox.ru> - 2012-07-23 03:29 +0400
                Re: Quotations revisited "Elizabeth D. Rather" <erather@forth.com> - 2012-07-22 14:22 -1000
                Re: Quotations revisited Aleksej Saushev <asau@inbox.ru> - 2012-07-23 05:46 +0400
                Re: Quotations revisited "Elizabeth D. Rather" <erather@forth.com> - 2012-07-22 21:46 -1000
                Re: Quotations revisited Aleksej Saushev <asau@inbox.ru> - 2012-07-25 03:31 +0400
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-23 16:50 +0000
                Re: Quotations revisited "Elizabeth D. Rather" <erather@forth.com> - 2012-07-23 07:57 -1000
                Re: Quotations revisited Aleksej Saushev <asau@inbox.ru> - 2012-07-25 03:38 +0400
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-26 13:01 +0000
                Re: Quotations revisited Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-21 12:10 +0000
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-21 09:19 -0500
                Re: Quotations revisited Bernd Paysan <bernd.paysan@gmx.de> - 2012-07-21 18:58 +0200
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-22 04:24 -0500
                Re: Quotations revisited Bernd Paysan <bernd.paysan@gmx.de> - 2012-07-22 14:25 +0200
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-22 11:11 -0500
                Re: Quotations revisited Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-21 19:29 +0000
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-23 16:31 +0000
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-23 12:21 -0500
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-23 17:32 +0000
                Re: Quotations revisited Paul Rubin <no.email@nospam.invalid> - 2012-07-23 11:23 -0700
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-24 03:28 -0500
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-25 13:15 +0000
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-25 11:47 -0500
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-26 13:06 +0000
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-26 09:50 -0500
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-26 15:11 +0000
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-26 11:06 -0500
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-26 16:46 +0000
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-27 04:52 -0500
                Re: Quotations revisited Paul Rubin <no.email@nospam.invalid> - 2012-07-26 09:48 -0700
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-27 14:51 +0000
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-28 08:29 -0500
                Re: Quotations revisited Paul Rubin <no.email@nospam.invalid> - 2012-07-29 20:55 -0700
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-30 04:40 -0500
                Re: Quotations revisited Paul Rubin <no.email@nospam.invalid> - 2012-07-31 23:46 -0700
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-08-01 04:30 -0500
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-23 16:17 +0000
                Re: Quotations revisited "Rod Pemberton" <do_not_have@notemailnot.cmm> - 2012-07-22 18:41 -0400
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-23 16:53 +0000
            Re: Quotations revisited Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-17 12:22 +0000
              Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-17 07:30 -0500
                Re: Quotations revisited Alex McDonald <blog@rivadpm.com> - 2012-07-17 06:34 -0700
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-17 09:04 -0500
                Re: Quotations revisited Alex McDonald <blog@rivadpm.com> - 2012-07-18 07:07 -0700
                Re: Quotations revisited Coos Haak <chforth@hccnet.nl> - 2012-07-18 17:43 +0200
                Re: Quotations revisited Alex McDonald <blog@rivadpm.com> - 2012-07-18 09:29 -0700
                Re: Quotations revisited Coos Haak <chforth@hccnet.nl> - 2012-07-18 20:59 +0200
                Re: Quotations revisited Coos Haak <chforth@hccnet.nl> - 2012-07-18 21:14 +0200
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-19 16:05 +0000
                Re: Quotations revisited Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-20 14:50 +0000
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-20 15:08 +0000
                Re: Quotations revisited Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-21 11:27 +0000
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-23 16:28 +0000
                Re: Quotations revisited Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-07-23 19:41 +0000
                Re: Quotations revisited Alex McDonald <blog@rivadpm.com> - 2012-07-18 10:18 -0700
                Re: Quotations revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-07-19 17:00 +0000
                Re: Quotations revisited Alex McDonald <blog@rivadpm.com> - 2012-07-19 15:34 -0700
                Re: Quotations revisited Alex McDonald <blog@rivadpm.com> - 2012-07-19 16:08 -0700
                Re: Quotations revisited Bernd Paysan <bernd.paysan@gmx.de> - 2012-07-17 20:09 +0200
  Re: Quotations revisited stephenXXX@mpeforth.com (Stephen Pelc) - 2012-07-16 12:01 +0000
    Re: Quotations revisited Paul Rubin <no.email@nospam.invalid> - 2012-07-16 10:42 -0700
      Re: Quotations revisited stephenXXX@mpeforth.com (Stephen Pelc) - 2012-07-16 18:06 +0000
        Re: Quotations revisited "Elizabeth D. Rather" <erather@forth.com> - 2012-07-16 11:08 -1000
          Re: Quotations revisited stephenXXX@mpeforth.com (Stephen Pelc) - 2012-07-16 21:38 +0000
            Re: Quotations revisited Bernd Paysan <bernd.paysan@gmx.de> - 2012-07-17 00:29 +0200
              Re: Quotations revisited "Elizabeth D. Rather" <erather@forth.com> - 2012-07-16 12:38 -1000
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-17 04:20 -0500
                Re: Quotations revisited Alex McDonald <blog@rivadpm.com> - 2012-07-17 03:21 -0700
                Re: Quotations revisited Alex McDonald <blog@rivadpm.com> - 2012-07-17 03:14 -0700
                Re: Quotations revisited Bernd Paysan <bernd.paysan@gmx.de> - 2012-07-17 19:58 +0200
                Re: Quotations revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-07-17 13:05 -0500
  Re: Quotations revisited stephenXXX@mpeforth.com (Stephen Pelc) - 2012-07-20 11:12 +0000
    Re: Quotations revisited Alex McDonald <blog@rivadpm.com> - 2012-07-20 05:40 -0700
      Re: Quotations revisited stephenXXX@mpeforth.com (Stephen Pelc) - 2012-07-20 15:55 +0000
    Re: Quotations revisited Paul Rubin <no.email@nospam.invalid> - 2012-07-22 20:54 -0700
      Re: Quotations revisited Aleksej Saushev <asau@inbox.ru> - 2012-07-25 03:55 +0400

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