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Groups > comp.lang.forth > #25979

Re: Execution tokens for return stack manipulation

From Andrew Haley <andrew29@littlepinkcloud.invalid>
Subject Re: Execution tokens for return stack manipulation
Newsgroups comp.lang.forth
References <l1q4vi$jdi$1@oravannahka.helsinki.fi> <D6KdncmsPd8EAN3PnZ2dnUVZ_vydnZ2d@supernews.com> <l1q7rr$lpd$1@oravannahka.helsinki.fi>
Message-ID <aO2dnRG2d5PQN93PnZ2dnUVZ_qydnZ2d@supernews.com> (permalink)
Date 2013-09-23 15:53 -0500

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Lauri Alanko <la@iki.fi> wrote:
> In article <D6KdncmsPd8EAN3PnZ2dnUVZ_vydnZ2d@supernews.com>,
> Andrew Haley  <andrew29@littlepinkcloud.invalid> wrote:
>> You can't tick and execute >R.
>> 
>> This is implied because of the interpretation semantics of >R:
> 
> Ah, that was it, thanks!
> 
> However, I must say this is somewhat non-obvious. The prohibition
> comes from 4.1.2, which forbids "attempting to obtain the execution
> token of a definition with undefined interpretation semantics".
> 
> But 3.4.3.1 says that EXECUTE executes the _execution_ semantics,
> which the return stack operations do have. And neither the glossary
> for the tick operations nor for EXECUTE mentions the constraint. So it
> is very hard to find out, unless one already knows where to look.

That's a fair complaint.  Perhaps we could just add a cross-reference
to the glossary for the tick operations?

I think it's fair to say that the Forth 200x discussions around the
area of rewording (or rewriting) the handling of compilation/
execution/interpretation semantics have been tortuous.  It's really
hard to get right in a way that allows all the variations of Forth
systems but prohibits the things that shouldn't be done.

Andrew.

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Thread

Execution tokens for return stack manipulation Lauri Alanko <la@iki.fi> - 2013-09-23 19:32 +0000
  Re: Execution tokens for return stack manipulation Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-09-23 14:59 -0500
    Re: Execution tokens for return stack manipulation Lauri Alanko <la@iki.fi> - 2013-09-23 20:21 +0000
      Re: Execution tokens for return stack manipulation Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-09-23 15:53 -0500
    Re: Execution tokens for return stack manipulation Bernd Paysan <bernd.paysan@gmx.de> - 2013-09-23 23:27 +0200
      Re: Execution tokens for return stack manipulation "Alex McDonald" <blog@rivadpm.com> - 2013-09-23 23:37 +0100
      Re: Execution tokens for return stack manipulation Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-09-24 06:52 -0500
        Re: Execution tokens for return stack manipulation anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-09-24 12:36 +0000
          Re: Execution tokens for return stack manipulation Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-09-24 12:10 -0500
            Re: Execution tokens for return stack manipulation Bernd Paysan <bernd.paysan@gmx.de> - 2013-09-24 22:22 +0200
        Re: Execution tokens for return stack manipulation Bernd Paysan <bernd.paysan@gmx.de> - 2013-09-24 16:14 +0200
          Re: Execution tokens for return stack manipulation Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-09-24 12:12 -0500
  Re: Execution tokens for return stack manipulation "Rod Pemberton" <dont_use_email@nohavenotit.com> - 2013-09-23 18:09 -0400
  Re: Execution tokens for return stack manipulation "Elizabeth D. Rather" <erather@forth.com> - 2013-09-23 12:40 -1000
    Re: Execution tokens for return stack manipulation Lauri Alanko <la@iki.fi> - 2013-09-23 22:43 +0000
      Re: Execution tokens for return stack manipulation Spam@ControlQ.com - 2013-09-24 01:38 -0400

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