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From: anton@mips.complang.tuwien.ac.at (Anton Ertl)
Newsgroups: comp.lang.forth
Subject: Re: VALUE and TO implementation
Date: Wed, 07 Aug 2024 06:11:03 GMT
Organization: Institut fuer Computersprachen, Technische Universitaet Wien
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dxf <dxforth@gmail.com> writes:
>On 6/08/2024 2:27 pm, dxf wrote:
>> ... 
>> ISTR dual-xt solutions also have problems with 'edge cases'.
>
>Works for state-smart but not dual-xt:
>
>  : ,"  postpone s"  dup c,  here  over allot  swap cmove ;
>
>  ," Hello world"

I did not understand at first what this code was supposed to do, in
particular why you would want to perform the compilation semantics of
S" outside a colon definition.

After some thinking I found that this code actually relies on a buggy
implementation of S" which does not implement the compilation
semantics of the standard S" in this usage.  It's better to write code
that does not rely on such bugs:

: ,"  ['] s" execute  dup c,  here  over allot  swap cmove ;

," Hello world"

or just

: ,"  '"' parse  dup c,  here  over allot  swap cmove ;

," Hello world"

As for the argument that this is supposed to be a problem of correct
implementations of S": Yes, one can write code that relies on a bug,
for every bug.  That does not justify the bug.

- anton
-- 
M. Anton Ertl  http://www.complang.tuwien.ac.at/anton/home.html
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