Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!weyrich!orville
From: orville@weyrich.UUCP (Orville R. Weyrich)
Newsgroups: comp.lang.fortran
Subject: Re: Is this a "feature"?
Message-ID: <1991May24.100709.2810@weyrich.UUCP>
Date: 24 May 91 10:07:09 GMT
References: <1991May23.160841.402@ac.dal.ca>
Reply-To: orville@weyrich.UUCP (Orville R. Weyrich)
Organization: Weyrich Computer Consulting
Lines: 44

In article <1991May23.160841.402@ac.dal.ca> scrutton@ac.dal.ca writes:
>I saw the super competent answers to the COMMON block initialization
>question and hope someone can give me a hand with a couple of my own.
>
>I'd like to find out if the SAVE statement existed in FORTRAN IV (66).

It was not in the IBM FORTRAN-G and FORTRAN-H compilers. It may have been an
extension to some other dialects (perhaps the Burroughs stack-oriented
hardware?)

>I've come across some old (stylistically) code which doesn't use the
>statement and depends on static allocation. Every compiler I've tried
>will let you get away with referencing local variables assigned in
>previous calls to that routine so it's either a standard `feature' or
>part of the standard.

The normal implementation allocates storage statically, in effect doing a
SAVE by default. The exceptions are when overlays are done in the linkage-
edit step and on certain stack-oriented Burroughs machines.

>
>I've also run across a DECODE statement which appears to be a precursor
>to the (what's it called...) I/O using character variables as file units.

DEC-10 and PDP-11 FORTRAN compilers implemented DECODE as an extension
to FORTRAN-66. Other implementations may have also. It is a precursor to
FORTRAN-77 I/O using character variables as I/O units (I think that WATFIV
was the forst to do this, thus helping to shape the standard).

>Is this yet another 66ism? VMS sure didn't like it but I thought 77 was
>upward compatible with 66.

The last time I looked, VAX/VMS FORTRAN did support some form of ENCODE/
DECODE, in order to maintain compatability with PDP-11 FORTRAN. This
non-standard feature may have been phased out since I last worked on a VAX.



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Orville R. Weyrich, Jr., Ph.D.                   Certified Systems Professional
Internet: orville%weyrich@uunet.uu.net             Weyrich Computer Consulting
Voice:    (602) 391-0821                         POB 5782, Scottsdale, AZ 85261
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