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From: ForthNet@willett.pgh.pa.us (ForthNet articles from GEnie)
Newsgroups: comp.lang.forth
Subject: ANS TC Magnet for Control, ABORT,QUIT..
Message-ID: <2240.UUL1.3#5129@willett.pgh.pa.us>
Date: 17 Jan 91 12:30:42 GMT
Organization: (n.) to be organized.  But that's not important right now.
Lines: 34

Category 10,  Topic 27
Message 33        Tue Jan 15, 1991
W.BADEN1 [Wil]               at 20:14 PST
 
Some readers may have the impression that my solution of the control flow
problem is complicated and unwieldy.  On the contrary it is as simple as it
can be and no simpler.

The six deficient and impossible-to-use system words of Forth-83 yield to two
elementary words that complete the word-set that every Forth must have.

One of these is an unconditional forward branch that complements the
unconditional backward branch that virtually every Forth system already has.

The other satisfies the minimum requirement to massage the implicit control
flow stack.

These two words can be added to any existing Forth system, even polyForth,
cmForth, figForth, Forth-79, and native machine code compilers, to give them
the ability to effect any control flow structure in a transparent and portable
way.

A further advantage of these words is that the occasional craving to roll-your-
own control flow structure can be satisfied by using these words directly
without having to define a never-used-again control structure.

The adoption of two words accomplishes what the six Forth-83 system extension
words were intended to do, but can't.

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