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From: toma@tekgvs.LABS.TEK.COM (Tom Almy)
Newsgroups: comp.lang.forth
Subject: Re: Incapsulation and visibility in Forth
Message-ID: <5694@tekgvs.LABS.TEK.COM>
Date: 3 Aug 89 15:10:28 GMT
References: <1@massormetrix.ida.liu.se>
Reply-To: toma@tekgvs.LABS.TEK.COM (Tom Almy)
Organization: Tektronix, Inc., Beaverton,  OR.
Lines: 25

In article <1@massormetrix.ida.liu.se> mikpa@massormetrix.ida.liu.se (Mikael Patel) writes:

>So what do you say Forthians? Seen something like this or maybe 
>an other approach! Tell us about it!

You can (permanently) hide headers by unlinking them or otherwise disposing
of them (if headers are kept separate).  The earliest approach I have seen,
in the Vol II, #5 issue of Forth Dimensions, involves three words INTERNAL
EXTERNAL and MODULE.  It is used:

INTERNAL

\ definitions which are local (headers will be unlinked)

EXTERNAL

\ definitions which are externally accessed -- they may call internal words

MODULE  \ excises headers

These can also be nested.  Very effective, and simple to implement.

Tom Almy
toma@tekgvs.labs.tek.com
Standard Disclaimers Apply