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Newbie alert: what is the ANS word for clearing the stack without aborting?

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  Newbie alert: what is the ANS word for clearing the stack without aborting? Chris Curl <ccurl609@gmail.com> - 2015-10-09 06:30 -0700
    Re: Newbie alert: what is the ANS word for clearing the stack without aborting? "WJ" <w_a_x_man@yahoo.com> - 2015-10-09 13:46 +0000
      Re: Newbie alert: what is the ANS word for clearing the stack without aborting? Coos Haak <chforth@hccnet.nl> - 2015-10-09 17:35 +0200
    Re: Newbie alert: what is the ANS word for clearing the stack without aborting? Mark Wills <markwills1970@gmail.com> - 2015-10-09 07:08 -0700
      Re: Newbie alert: what is the ANS word for clearing the stack without aborting? Coos Haak <chforth@hccnet.nl> - 2015-10-09 17:38 +0200
    Re: Newbie alert: what is the ANS word for clearing the stack without aborting? Ching-Tang Tseng <ilikeforth@gmail.com> - 2015-10-09 08:10 -0700
      Re: Newbie alert: what is the ANS word for clearing the stack without aborting? Coos Haak <chforth@hccnet.nl> - 2015-10-09 17:42 +0200
    Re: Newbie alert: what is the ANS word for clearing the stack without aborting? Chris Curl <ccurl609@gmail.com> - 2015-10-09 08:57 -0700
    Re: Newbie alert: what is the ANS word for clearing the stack without aborting? Ching-Tang Tseng <ilikeforth@gmail.com> - 2015-10-09 08:59 -0700
    Re: Newbie alert: what is the ANS word for clearing the stack without aborting? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-10-09 16:00 +0000
      Re: Newbie alert: what is the ANS word for clearing the stack without aborting? "Elizabeth D. Rather" <erather@forth.com> - 2015-10-09 08:38 -1000
        Re: Newbie alert: what is the ANS word for clearing the stack without aborting? Chris Curl <ccurl609@gmail.com> - 2015-10-09 12:31 -0700
          Re: Newbie alert: what is the ANS word for clearing the stack without aborting? "Elizabeth D. Rather" <erather@forth.com> - 2015-10-09 10:29 -1000
          Re: Newbie alert: what is the ANS word for clearing the stack without aborting? "HAA" <someone@microsoft.com> - 2015-10-11 11:51 +1000
    Re: Newbie alert: what is the ANS word for clearing the stack without aborting? Ching-Tang Tseng <ilikeforth@gmail.com> - 2015-10-10 18:28 -0700
      Re: Newbie alert: what is the ANS word for clearing the stack without aborting? hughaguilar96@gmail.com - 2015-10-10 22:53 -0700

#42497 — Newbie alert: what is the ANS word for clearing the stack without aborting?

I have seen a 0SP word bandied about, which is easy enough to implement.

     : 0SP DEPTH ?DUP IF 0 DO DROP LOOP THEN ;

But I didn't see a word in the standard for it though.

If there is no word in the standard for it, what word do you folks use?

Even though I seriously doubt my implementation will 100% ANS compliant, I figure I might as well use word names that most folks use for stuff most people want to do.

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#42498

Chris Curl wrote:

> I have seen a 0SP word bandied about, which is easy enough to implement.
> 
>      : 0SP DEPTH ?DUP IF 0 DO DROP LOOP THEN ;

The standard Forth word to clear the stack is "clr".

Oforth:

>2 3 4 .s
[1] (Integer) 4
[2] (Integer) 3
[3] (Integer) 2
ok
>clr .s
Empty

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#42506

Op Fri, 9 Oct 2015 13:46:29 +0000 (UTC) schreef WJ:

> Chris Curl wrote:
> 
>> I have seen a 0SP word bandied about, which is easy enough to implement.
>> 
>>      : 0SP DEPTH ?DUP IF 0 DO DROP LOOP THEN ;
> 
> The standard Forth word to clear the stack is "clr".
Which standard?

groet Coos

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#42501

On Friday, 9 October 2015 14:30:47 UTC+1, Chris Curl  wrote:
> I have seen a 0SP word bandied about, which is easy enough to implement.
> 
>      : 0SP DEPTH ?DUP IF 0 DO DROP LOOP THEN ;
> 
> But I didn't see a word in the standard for it though.
> 
> If there is no word in the standard for it, what word do you folks use?
> 
> Even though I seriously doubt my implementation will 100% ANS compliant, I figure I might as well use word names that most folks use for stuff most people want to do.

: clr ( ... -- ) s0 sp! ;

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#42508

Op Fri, 9 Oct 2015 07:08:40 -0700 (PDT) schreef Mark Wills:

> On Friday, 9 October 2015 14:30:47 UTC+1, Chris Curl  wrote:
>> I have seen a 0SP word bandied about, which is easy enough to implement.
>> 
>>      : 0SP DEPTH ?DUP IF 0 DO DROP LOOP THEN ;
>> 
>> But I didn't see a word in the standard for it though.
>> 
>> If there is no word in the standard for it, what word do you folks use?
>> 
>> Even though I seriously doubt my implementation will 100% ANS compliant, I figure I might as well use word names that most folks use for stuff most people want to do.
> 
>: clr ( ... -- ) s0 sp! ;

: clr  dsp0 dsp! ;
I may write this, because s0 sp! dsp0 dsp! are never declared
in the standard ;-)

: clr  begin depth while drop repeat ;
Slow version that uses only standard words

groet Coos

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#42504

'''''''' Enter

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#42510

Op Fri, 9 Oct 2015 08:10:40 -0700 (PDT) schreef Ching-Tang Tseng:

> '''''''

It clears the stack already, but leaves an error
message on the screen and aborts.
So you can not use this in the middle of source text.

groet Coos

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#42511

Thanks folks. CLR it is.

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#42512

Coos Haak,

like

Thanks

Ching

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#42513

Chris Curl <ccurl609@gmail.com> writes:
>If there is no word in the standard for it, what word do you folks use?

ABORT clears the stack (but also produces an error message in Gforth).

Gforth has CLEARSTACK (this only clears the data stack).

- 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
   EuroForth 2015: http://www.rigwit.co.uk/EuroForth2015/

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#42522

On 10/9/15 6:00 AM, Anton Ertl wrote:
> Chris Curl <ccurl609@gmail.com> writes:
>> If there is no word in the standard for it, what word do you folks use?
>
> ABORT clears the stack (but also produces an error message in Gforth).
>
> Gforth has CLEARSTACK (this only clears the data stack).

Such a word should be used very rarely, and mostly in debugging. The 
reason is that you want your Forth words to be usable in any context; 
they should only affect their own immediate environment. The general 
rule is, a word should remove its arguments and leave only explicit 
results. It shouldn't touch anything else on the stack. When you're 
testing, it's often helpful to clear your stack and then put specific 
things on it and call the word or words you're testing, and ABORT is 
just fine for that case.

Cheers,
Elizabeth

-- 
==================================================
Elizabeth D. Rather   (US & Canada)   800-55-FORTH
FORTH Inc.                         +1 310.999.6784
5959 West Century Blvd. Suite 700
Los Angeles, CA 90045
http://www.forth.com

"Forth-based products and Services for real-time
applications since 1973."
==================================================

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#42525

On Friday, October 9, 2015 at 2:38:38 PM UTC-4, Elizabeth D. Rather wrote:
> Such a word should be used very rarely, and mostly in debugging. The 
> reason is that you want your Forth words to be usable in any context; 
> they should only affect their own immediate environment. The general 
> rule is, a word should remove its arguments and leave only explicit 
> results. It shouldn't touch anything else on the stack. When you're 
> testing, it's often helpful to clear your stack and then put specific 
> things on it and call the word or words you're testing, and ABORT is 
> just fine for that case.
> 
> Cheers,
> Elizabeth
> 
Understood and agreed. It is just that, as I'm sure you are well aware,
spending alot of time developing a new word can result in lots of
times where the stack has remnants on it, so clearing the stack is a
very common thing, at least for me. Until now, I have just typed in an
unknown word (like ..), which is fine. But I was wondering if there was
word people commonly use or it, or even if there was one in the standard
that I wasn't aware of.

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#42530

On 10/9/15 9:31 AM, Chris Curl wrote:
> On Friday, October 9, 2015 at 2:38:38 PM UTC-4, Elizabeth D. Rather wrote:
>> Such a word should be used very rarely, and mostly in debugging. The
>> reason is that you want your Forth words to be usable in any context;
>> they should only affect their own immediate environment. The general
>> rule is, a word should remove its arguments and leave only explicit
>> results. It shouldn't touch anything else on the stack. When you're
>> testing, it's often helpful to clear your stack and then put specific
>> things on it and call the word or words you're testing, and ABORT is
>> just fine for that case.
>>
>> Cheers,
>> Elizabeth
>>
> Understood and agreed. It is just that, as I'm sure you are well aware,
> spending alot of time developing a new word can result in lots of
> times where the stack has remnants on it, so clearing the stack is a
> very common thing, at least for me. Until now, I have just typed in an
> unknown word (like ..), which is fine. But I was wondering if there was
> word people commonly use or it, or even if there was one in the standard
> that I wasn't aware of.
>

If the remnants are things you know about (i.e., results) yes, this is 
very common, and .. is a fine practical solution, and the sort of thing 
most of us do.

Cheers,
Elizabeth

-- 
==================================================
Elizabeth D. Rather   (US & Canada)   800-55-FORTH
FORTH Inc.                         +1 310.999.6784
5959 West Century Blvd. Suite 700
Los Angeles, CA 90045
http://www.forth.com

"Forth-based products and Services for real-time
applications since 1973."
==================================================

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#42556

Chris Curl wrote:
> ...
> Until now, I have just typed in an
> unknown word (like ..), which is fine. But I was wondering if there was
> word people commonly use or it, or even if there was one in the standard
> that I wasn't aware of.

In my experience it's rare for a program to need such a word, so (for me)
your former method is fine and doesn't waste a word.  The 'handy hint'
Brodie suggests in Starting Forth (1st ed. p137) is shorter than ABORT
and is exactly the one I use to this day - so much so it has become
automatic.  I couldn't use Forth without it :)

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#42558

I had ever tried to design a FORTH system for our blind friend to use.  It has sound output function.
In that my personal experience, I felt use 
'''''''''''' Enter 
method is better, owing to the ' is the nearest one key to the Enter, even the blind friend is very ease to operate by right hand only.

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#42562

On Saturday, October 10, 2015 at 6:28:11 PM UTC-7, Ching-Tang Tseng wrote:
> I had ever tried to design a FORTH system for our blind friend to use.  It has sound output function.
> In that my personal experience, I felt use 
> '''''''''''' Enter 
> method is better, owing to the ' is the nearest one key to the Enter, even the blind friend is very ease to operate by right hand only.

I've always just done this too --- I've never given any thought to defining a word specifically for it.

If I did write such a word, I would give it a vulgar name though as I would only be using it in cases in which I had screwed up and needed to clean up a mess. ;-)

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