Re: Adding NTs or making XTs the only opaque Forth type

From	stephenXXX@mpeforth.com (Stephen Pelc)
Newsgroups	comp.lang.forth
Subject	Re: Adding NTs or making XTs the only opaque Forth type
Organization	MPE
Message-ID	<52011c79.2295168172@news.demon.co.uk> (permalink)
References	<ktp0gt$mif$1@dont-email.me> <2013Aug6.090159@mips.complang.tuwien.ac.at>
Date	2013-08-06 16:10 +0000

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On Tue, 06 Aug 2013 07:01:59 GMT, anton@mips.complang.tuwien.ac.at
(Anton Ertl) wrote:

>"Alex McDonald" <blog@rivadpm.com> writes:
>> the TC's unwritten
>>intention, expressed by Elizabeth Rather, that an xt as a single opaque
>>type.
>
>It's unclear what that means, however, if there was such an intent at
>all.  A few interpretations that come to mind:
>
>1) They did not like the words for dealing with headers in systems
>like fig-Forth: There you have one header with name field, link field
>code field, and parameter field, and words for going from one field to
>the next.  To go from the name field to the parameter field, you had
>to do something like "1 TRAVERSE LFA> >PFA".  I think it's very likely
>that this is what Elizabeth Rather is remembering, and I think we can
>find consensus that we do not want this kind of design.

That situation was nasty and tended to impose implementation styles.

>2) They did not standardize stuff like NT>STRING, because that would
>have required putting an NT in the standard, and they (or at least
>some of them) did not want to go there.

I do not recollect anyone proposing such a thing. At the time, I
believe that the TC members were content for such words to be system
dependent.

>3) Each named word has one xt and that represents everything about it.
>If that was the unwritten intent, it directly contradicts the written
>intent of supporting different implementation approaches,

Please justify such an assertion. At present, you repeat this as if
it was obvious.

> including
>ones where interpretation semantics and compilation semantics are
>associated with different xts (which is reflected in the normative
>specification of FIND and maybe other places).  And it is incompatible
>with the specification of COMPILE, (one can destandardize the xts of
>S" and TO to work around that, but that's incompatible with this
>version of the claimed intent).

We could have a "heated debate" about gforth's COMPILE, and S" but
this is not the place. Classifying the separate interpretation and
compilation behaviours as xts is what leads to the confusion. If
we call them ixts and cxts and treat them as internal factors, then
life becomes clearer.

>I have used access to the name of the word in application contexts.  I
>would expect that NT>STRING would be used that way, too.  So
>perfomance of NT>STRING is relevant.

Please could you give examples where the performance is important.

>But allowing nt!=xt would not require a change in his product, as
>nt=xt would be allowed.  By contrast, requiring nt=xt would require a
>changes in other products, and he has said so in this discussion. I
>guess he is so nonchalant about that because it's not his product that
>would be affected.

MPE has changed VFX as a result of your statements about standards
compliance. That cost real money. Please have the grace to at least
consider my position and realise that there may be faults in gforth.

Stephen


-- 
Stephen Pelc, stephenXXX@mpeforth.com
MicroProcessor Engineering Ltd - More Real, Less Time
133 Hill Lane, Southampton SO15 5AF, England
tel: +44 (0)23 8063 1441, fax: +44 (0)23 8033 9691
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Thread

Adding NTs or making XTs the only opaque Forth type "Alex McDonald" <blog@rivadpm.com> - 2013-08-05 21:11 +0100
  Re: Adding NTs or making XTs the only opaque Forth type anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-06 07:01 +0000
    Re: Adding NTs or making XTs the only opaque Forth type stephenXXX@mpeforth.com (Stephen Pelc) - 2013-08-06 16:10 +0000
      Re: Adding NTs or making XTs the only opaque Forth type Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-06 22:22 +0200
  Re: Adding NTs or making XTs the only opaque Forth type stephenXXX@mpeforth.com (Stephen Pelc) - 2013-08-06 15:54 +0000
    Re: Adding NTs or making XTs the only opaque Forth type albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-08-06 17:43 +0000
      Re: Adding NTs or making XTs the only opaque Forth type "Elizabeth D. Rather" <erather@forth.com> - 2013-08-06 13:16 -1000
        Re: Adding NTs or making XTs the only opaque Forth type "Elizabeth D. Rather" <erather@forth.com> - 2013-08-06 13:55 -1000
        Re: Adding NTs or making XTs the only opaque Forth type Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-07 02:33 +0200
          Re: Adding NTs or making XTs the only opaque Forth type "Alex McDonald" <blog@rivadpm.com> - 2013-08-07 16:29 +0100
            Re: Adding NTs or making XTs the only opaque Forth type Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-07 10:54 -0500
              Re: Adding NTs or making XTs the only opaque Forth type "Alex McDonald" <blog@rivadpm.com> - 2013-08-07 17:10 +0100
                Re: Adding NTs or making XTs the only opaque Forth type Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-07 12:06 -0500
                Re: Adding NTs or making XTs the only opaque Forth type "Alex McDonald" <blog@rivadpm.com> - 2013-08-07 18:43 +0100
                Re: Adding NTs or making XTs the only opaque Forth type Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-07 12:47 -0500
                Re: Adding NTs or making XTs the only opaque Forth type "Alex McDonald" <blog@rivadpm.com> - 2013-08-07 19:14 +0100
                Re: Adding NTs or making XTs the only opaque Forth type Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-07 15:13 -0500
                Re: Adding NTs or making XTs the only opaque Forth type "Alex McDonald" <blog@rivadpm.com> - 2013-08-07 23:09 +0100
                Re: Adding NTs or making XTs the only opaque Forth type anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-08 13:45 +0000
                Re: Adding NTs or making XTs the only opaque Forth type "Alex McDonald" <blog@rivadpm.com> - 2013-08-08 15:41 +0100
                Re: Adding NTs or making XTs the only opaque Forth type Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-08 10:29 -0500
                Re: Adding NTs or making XTs the only opaque Forth type anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-08 16:15 +0000
                Re: Adding NTs or making XTs the only opaque Forth type Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-08 19:25 +0200
                Re: Adding NTs or making XTs the only opaque Forth type Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-08 14:05 -0500
                Re: Adding NTs or making XTs the only opaque Forth type anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-12 16:28 +0000
                Re: Adding NTs or making XTs the only opaque Forth type Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-12 12:44 -0500
                Re: Adding NTs or making XTs the only opaque Forth type anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-13 07:08 +0000
                Re: Adding NTs or making XTs the only opaque Forth type Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-13 03:40 -0500
                Re: Adding NTs or making XTs the only opaque Forth type anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-13 09:47 +0000
                Re: Adding NTs or making XTs the only opaque Forth type Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-13 05:55 -0500
                Re: Adding NTs or making XTs the only opaque Forth type anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-13 12:18 +0000
                Re: Adding NTs or making XTs the only opaque Forth type Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-13 10:32 -0500

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