Why these original FORTRAN quirks?
in [Fortran]
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From: Andrew Swallow on 22 Oct 2006 10:42 glen herrmannsfeldt wrote: [snip] > > As for generally doing no harm, I think you would have to exclude all > floating point arithmetic operations, as they tend to do harm more > often than one would like. Do we still need floating point operations? Could they be replaced by say 128 bit fixed point variables - Sign bit, 63 bit integer and 64 bit fraction? Andrew Swallow
From: Gary Scott on 22 Oct 2006 11:10 glen herrmannsfeldt wrote: > Gary Scott wrote: > > (snip) > >>> And surely a suffix ".f" (which I saw as advice to someone in this >>> forum) is equivalent to the normal ".for" to indicate a fixed-format >>> program to an F90 compiler ? > > >> That wouldn't apply to some OS though that don't have a concept of a >> file name "suffix". > > > Older DEC OSs, later adapted by DOS, had the suffix as part of the file > system. Some allowed for a six character file name and a three > character extension. For VAX/VMS the shortest possible file name is .; > > For unix, it was convention to add a . suffix to names, but to the > system . was just another character. If . was not a legal character, > one could find another separator, or specify that the last character > of the name was the indicating suffix. > Wouldn't work on VM or VOS unless you adopted a very shortened name part. VM has a filetype, but the separation character is a space: "copyfile filename filetype filemode (space separated list of options" > -- glen > -- Gary Scott mailto:garylscott(a)sbcglobal dot net Fortran Library: http://www.fortranlib.com Support the Original G95 Project: http://www.g95.org -OR- Support the GNU GFortran Project: http://gcc.gnu.org/fortran/index.html Why are there two? God only knows. If you want to do the impossible, don't hire an expert because he knows it can't be done. -- Henry Ford
From: Walter Spector on 22 Oct 2006 14:25 "William J. Leary Jr." wrote: > > "Terence" <tbwright(a)cantv.net> wrote in message > news:1161472385.953880.177910(a)m73g2000cwd.googlegroups.com... > > My memory is that at least one of the earlier Fortran compilers > > I worked with allowed SIX-letter variable names only in the main > > program.And FIVE-letter names as variables in subroutines and > > functions. > > This sounds vaguely familiar to me. I used FORTRAN (when it was still all > uppercase) on DG, DEC and [[some other]] computers back in the late 70's and > early 80's. One of them, I can't recall which, had some limitation like that. The Fortran compiler on the 16-bit Data General Eclipse system, running the AOS operating system, only supported 5 character variable names. It was a major annoyance on an otherwise very nice machine: I really liked AOS, and it was a lot faster than DEC machines of the day. (Well, maybe not faster than the 11/70.) DG finally released a compiler which supported longer names sometime in 1979. IIRC, they took the opportunity to go 'all the way' to 8 characters. Walt
From: Gary Scott on 22 Oct 2006 14:59 Walter Spector wrote: > "William J. Leary Jr." wrote: > >>"Terence" <tbwright(a)cantv.net> wrote in message >>news:1161472385.953880.177910(a)m73g2000cwd.googlegroups.com... >> >>>My memory is that at least one of the earlier Fortran compilers >>>I worked with allowed SIX-letter variable names only in the main >>>program.And FIVE-letter names as variables in subroutines and >>>functions. >> >>This sounds vaguely familiar to me. I used FORTRAN (when it was still all >>uppercase) on DG, DEC and [[some other]] computers back in the late 70's and >>early 80's. One of them, I can't recall which, had some limitation like that. > > > The Fortran compiler on the 16-bit Data General Eclipse system, running > the AOS operating system, only supported 5 character variable names. Hmm, I think that's the one I first learned assembly on in school...later the 8085 and the 6800 were taught in the same class. > It was a major annoyance on an otherwise very nice machine: I really > liked AOS, and it was a lot faster than DEC machines of the day. (Well, > maybe not faster than the 11/70.) > > DG finally released a compiler which supported longer names sometime in 1979. > IIRC, they took the opportunity to go 'all the way' to 8 characters. > > Walt -- Gary Scott mailto:garylscott(a)sbcglobal dot net Fortran Library: http://www.fortranlib.com Support the Original G95 Project: http://www.g95.org -OR- Support the GNU GFortran Project: http://gcc.gnu.org/fortran/index.html Why are there two? God only knows. If you want to do the impossible, don't hire an expert because he knows it can't be done. -- Henry Ford
From: Rostyslaw J. Lewyckyj on 22 Oct 2006 19:31
Richard Steiner wrote: > Here in alt.folklore.computers, > Gary Scott <garylscott(a)sbcglobal.net> spake unto us, saying: > > >>Richard Steiner wrote: >> >> >>>I've worked with the 6-character limit since 1988, and I still find it >>>easier to read the variable names in those older FORTRAN programs than >>>I do in the newer C++ code I have to support because the FORTRAN folks >>>were *far* more disciplined in their variable naming conventions. >> >>I tend to agree in that I never had much difficulty with 6 character >>names because there was considerable discipline used in the naming >>conventions we used. However, moderately increasing the lengths beyond >>6 does provide a modest improvement in readability and you can still use >>a disciplined approach to your naming convention with increased >>flexibility. > > > Yes, I could see 10 or 12 characters being quite useful, but things get > tedious to type quite quickly. :-( > > Even eight (8) characters would be an improvement, though. > I don't get it. Even if 128 character variable names are allowed, that doesn't mean that all, or any of the names you chose to use MUST be 128 characters long! |