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From: dwp@willett.pgh.pa.us (Doug Philips)
Newsgroups: comp.lang.forth
Subject: Re: Broken cmForth
Message-ID: <2409.UUL1.3#5129@willett.pgh.pa.us>
Date: 24 Feb 91 02:50:43 GMT
References: <9102222023.AA15724@ucbvax.Berkeley.EDU>
Organization: (n.) to be organized.  But that's not important right now.
Lines: 71

In article <9102222023.AA15724@ucbvax.Berkeley.EDU>,
	wmb@MITCH.ENG.SUN.COM (Mitch Bradley) writes:
+In any case, it still supports my orginal point; FOR .. NEXT is not
+an unmitigated win in all circumstances.  Here is a real live example
+of a particular weakness of FOR .. NEXT compared to DO .. LOOP , and a
+good Forth programmer broke a well-understood function as a result.

I might be inclined to reply to this by saying that CM is not your
average Forth programmer.  No reason to assume he can't make mistakes
or blunders, nor that he won't change his mind.  I would be interested
in hereing further justification.  Was the THRU bug no big deal?  Was
it better factored (as I think it was Frank suggested) this way?
Personally I believe that the bug is that THRU needed more than just a
replace-string done on it.  That FOR NEXT is slightly inferior in this
case doesn't sound the death nell for me as it seems for you.  Perhaps
one of the straws on the camels back, but not that interesting in and
of itself.

+There's nothing inherently wrong with FOR .. NEXT per se, but I can't
+accept the claim that the existence of FOR .. NEXT renders DO .. LOOP
+useless.

As I said in an earlier post, they are nearly isomorphic.  I think
this is an interesting illustration of the deceptive simplicity of
Forth.  Simplicity doesn't "just exist," but is always relative to
something.  Whether DO LOOP or FOR NEXT is "simpler" or "more elegant"
or ....  depends on what you are trying to do.

+The problem is that crummy systems just keep on coming, and many people
+have been and are turned off of Forth because of bad experiences with
+crummy Forth systems.

+I do NOT equate "bad" with PD.  There are several completely competent
+PD systems out there, F-PC and F-83 to name just two.  The problem that
+I am talking about is when somebody posts the Forth that they wrote
+in 2 weeks for their "CS 202" project and it gets stuck up on better
+bulletin boards everywhere.

"Most bad systems are PD, Therefore most PD systems are bad."  I
meant the former, not the latter.  Sorry for any confusion.

It is interesting to note that the same thing doesn't happen with C
compilers/run-time systems.  One of Forth's strengths seems to cast
a bad light here.

+Most people are careful how they spend their own money, and will make
+do with something that is free rather than commit the bucks.

That explains why people might choose a "free" PD/Shareware system,
but not why there are so many to choose from.

+The above diatribe is part of my added value.  Another is printed, bound
+documentation (which lots of people want; no kidding).  Another is
+purely administrative; you send me money, I send you a disk.  A lot
+of people don't want to fool around with searching for and downloading
+a PD system, or figuring out how to get the bits onto the target
+machine.

Printed documentation is a BIG plus.  Not just stuff you can run off
on a half decent dot matrix printer, but nice bound, laser output with
pictures, etc.  Not having to maintain the core system itself, i.e.
unsolicited updates and bug fixes, are also BIG pluses.

Thanks for the detailed reply.  I don't have any dispute with what you
said.  I guess one thing you didn't say is that the quality of the
implementation is much more crucial for commercial success than
PD/Shareware "success."

-Doug
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