Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!ucsd!ucbvax!PENNDRLS.BITNET!DAVID
From: DAVID@PENNDRLS.BITNET
Newsgroups: comp.lang.forth
Subject: Re:  Basis for my misgivings about the change of VOCABULARY....
Message-ID: <9011022135.AA23813@ucbvax.Berkeley.EDU>
Date: 1 Nov 90 18:36:43 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: DAVID%PENNDRLS.BITNET@SCFVM.GSFC.NASA.GOV
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Frank Earl writes:
>and you have to re-write loads of code) [ PLEASE NOTE- I have YET to see proof
>positive that I WON'T have re-write many portions of my 83 standard code or
>claim an environmental dependency (Of which, similar code in C DOESN'T HAVE
>TO!!)]   I'm all for the standard, I'm just getting the feeling that it may hav
e

I don't know how many times those of us who (I hope) understand what the
standard is trying to do have to repeat this before it will sink in,
but here goes one more try.  Please excuse the emphasis, but I feel
like this argument has gone around too many times (not by you, Frank,
you just happened by at the wrong moment :-).

If you currently have code that is 83 (or 79) standard, then if the
vendors rewrite their systems so that they are compliant and do not
delete any features (and the standard is specifically designed so that
they can do this), then your code will be EXACTLY AS PORTABLE AS IT WAS
BEFORE THE STANDARD, no more, AND NO LESS.  If you choose to take the
time to *rewrite* your code to be ANSI compliant (yes, EVERYBODY will
have to rewrite to achieve that) then your code will become portable to
EVERY ANSI COMPLIANT SYSTEM, including many on which your code would not
(before the standard) have had a prayer running.  The standard is not,
AND CAN NEVER BE, a magic wand which you can wave and say 'my code is
portable'.  YOUR CURRENT CODE IS EXACTLY AS PORTABLE AS IT CURRENTLY
IS, AND THE STANDARDS COMMITTEE CANNOT CHANGE THAT.

To rephrase, the intent is to AVOID BREAKING CODE THAT WORKS NOW, but
to provide standard facilities so that code that is FULLY portable CAN
be written by those who need to do so.

-- R. David Murray    (DAVID@PENNDRLS.BITNET, DAVID@PENNDRLS.UPENN.EDU)

P.S.: 'Similar code in C' (whatever that is) was portable after the ANSI
C standard only insofar as it was portable before the C standard, or
because the standard broke somebody else's code.  Because C compilers
are harder to write, there was more uniformity among C implementations
than there are among FORTH implementations, and so there were fewer
problem areas.  (But, note, I'm *still* not sure how to declare,
reference, and initialize a variable at the outermost level of a C
program so that it will be portable!)