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From: Mitch.Bradley@ENG.SUN.COM
Newsgroups: comp.lang.forth
Subject: Re: ARCHITECTURE and IMPLEMENTATION
Message-ID: <9105081518.AA01115@ucbvax.Berkeley.EDU>
Date: 8 May 91 01:07:42 GMT
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Reply-To: Mitch.Bradley%ENG.SUN.COM@SCFVM.GSFC.NASA.GOV
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Lines: 42

The distinction between architecture and implementation is indeed
important.

However, the place where one chooses to draw the line between
what is architecture and what is implementation is purely arbitrary.

In a spectrum from "abstract" to "concrete", FIG-Forth and its derivatives
drew the dividing line between architecture and implementation rather close
to the "concrete" end of the spectrum.

The trend in recent years has been to move the line in the "abstract"
direction.

> The problem that Forth faces is that, during the past 6 years,
> there have appeared languages which are called "Forth" but which
> differ from one another (and from traditional Forth) in matters of
> architecture. Because they differ in architecture, they are actually
> different languages.

This is true only if people agree where the dividing line is and ought
to be.

Personally, I believe that the dividing line should be toward the
"abstract" end of the spectrum.

I base this on the observation that "non-traditional" Forth systems
have been quite successful in the marketplace of late, often at the
expense of more traditional "model-based" implementations.

Even if we all decide to agree that a model-based "concrete" architecture
is the way to go, I doubt that it will keep Forth implementors from
taking an abstract view of what Forth is, and thus achieving speed
advantages on real machines.  Users have voted by purchasing fast
implementations.

You can try to lead people by telling them which way to go, but the
most successful leaders lead people in the way they already want to go.

I think the marketplace has already decided in favor of the abstract
approach.

Mitch.Bradley@Eng.Sun.COM