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Re: Word lists and word sets

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minforth@arcor.de writes:
>I am not really familiar with the Standard. I am wondering about: is there =
>any real correlation between word sets and word lists?
>
>After looking it up I gathered that word sets are only word clusters in the=
> standard document.

Yes.

> On the other hand they are not independent / orthogonal=
> from each other (f.ex. BLOCK and FILE share disk access, FILE and EXCEPTIO=
>N share ior exeception identifiers).

You mean, the wordsets depend on each other? 

In Forth-94 (no longer in -2012) a system with FILE words is
guaranteed to support the block words.

There is no dependence between FILE or MEMORY-ACCESS (both of which
produce ior values), and EXCEPTION.  If you have THROW from the
EXCEPTION wordset, you can THROW the iors in Forth-2012 (and, if the
system follows the recommendation in FOrth-94, also in Forth-94).

>Then there is this strange word ENVIRONMENT? seemingly without practical us=
>age, because querying word set designators is not much worth in real world =
>applications.   

One potential use of querying for wordsets could have been to give an
indication to the system that the program uses the wordset and that it
should load it right away and report it present.  However,none of the
mainstream Forth systems work that way: Gforth contains everything
from the start, and SwiftForth and VFX don't take the hint, and in a
display of ultimate user-friendlyness require the user to divine the
system-specific magic incantation for loading the missing wordsets.

So, because wordset queries were neglected by systems, and
consequently, also by programmers, in Forth-94, in Forth-2012 we made
them obsolescent rather than updating them.  There is now also
[DEFINED] and [UNDEFINED], which, while not telling whether the
queried word corresponds to the Forth standard, at least gives a
definitive answer instead of the don't-know result that ENVIRONMENT?
may produce.

ENVIRONMENT? also has other uses besides wordset queries.  E.g., you
can use it to query for various sizes.

- 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 2016: http://www.euroforth.org/ef16/

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Word lists and word sets minforth@arcor.de - 2016-11-03 09:37 -0700
  Re: Word lists and word sets Mark Wills <markwills1970@gmail.com> - 2016-11-03 14:25 -0700
    Re: Word lists and word sets anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-03 22:40 +0000
  Re: Word lists and word sets anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-03 21:57 +0000
  Re: Word lists and word sets minforth@arcor.de - 2016-11-04 06:59 -0700
    Re: Word lists and word sets anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-11-04 17:09 +0000

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