Delays for implementations of Fortran features

[Colin Paul Gloster <Colin_Paul_Gloster@ACM.org>]

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Dear Ada programmers:

Compilers for Fortran codes are lagging behind the Fortran standard.

Regards,
Colin Paul Gloster



On January 13th, 2014, Tom Clune sent to COMP-FORTRAN-90@JISCMail.ac.UK:
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|"On Jan 12, 2014, at 4:44 PM, John Harper <harper@MSOR.VUW.AC.NZ> wrote:    |
|                                                                            |
|      On Fri, 10 Jan 2014, Tom Clune wrote:                                 |
|                                                                            |
|            Date: Fri, 10 Jan 2014 12:48:54 -0500                           |
|            From: Tom Clune <Thomas.L.Clune@NASA.GOV>                       |
|            Reply-To: Fortran 90 List                                       |
|            <COMP-FORTRAN-90@JISCMAIL.AC.UK>                                |
|            To: COMP-FORTRAN-90@JISCMAIL.AC.UK                              |
|            Subject: Re: retraction (was Re: Is this legal                  |
|            (F2003 or F2008)?)                                              |
|                                                                            |
|            On Jan 10, 2014, at 11:36 AM, "Lionel, Steve"                   |
|            <steve.lionel@intel.com> wrote:                                 |
|                                                                            |
|                  Tom Clune wrote:                                          |
|                                                                            |
|                  ➢ The strategy I posted yesterday was                     |
|                  flawed in that it attempted to assign a                   |
|                  pointer to an internal procedure.   Most                  |
|                  compiler accepted it, and I had not                       |
|                  realized that such a restriction                          |
|                  existed.                                                  |
|                                                                            |
|                  That is legal F2008, and some compilers                   |
|                  have supported it for a while.                            |
|                                                                            |
|                                                                            |
|            Steve,                                                          |
|                                                                            |
|            Thanks for the clarification.                                   |
|                                                                            |
|            It has become an interesting juggling act for                   |
|            developers that must choose between portability and             |
|            powerful new features.    There are a number of                 |
|            things in F2008 that I would absolutely use if all 3            |
|            of my baseline compilers supported them.  (I don't              |
|            intend to name names here.)                                     |
|                                                                            |
|            Cheers,                                                         |
|                                                                            |
|            - Tom                                                           |
|                                                                            |
|                                                                            |
|      You're lucky if your only problem is unsupported f2008 features.      |
|      I still avoid f2003 features because some of them are                 |
|      unsupported by some of the                                            |
|      4 compilers I use. So I'm stuck with a Fortran dialect that's 11      |
|      years                                                                 |
|      out of date. One non-f95 feature I use occasionally is SYSTEM         |
|      which is non-standard but all 4 compilers support it, albeit in       |
|      different ways: some treat it as an intrinsic subroutine, others      |
|      as an always-available external one, but that's OK if the             |
|      program says neither INTRINSIC SYSTEM nor EXTERNAL SYSTEM. I use      |
|      it because the compilers don't all support                            |
|      the f2008 feature EXECUTE_COMMAND_LINE.                               |
|                                                                            |
|                                                                            |
|Sure, there are some F2003 features that I must avoid because one or more   |
|compiler does not support them.    One fear that I have is that I've        |
|"learned" to avoid some of these features and will never integrate them into|
|my code when they become available.   OTOH, I eagerly await the day that    |
|gfortran supports deferred-length strings as structure components.          |
|                                                                            |
|And, like yourself, I will use nonstandard, but widely portable extensions  |
|such as SYSTEM when appropriate.   Occasionally I'll even use #ifdef to     |
|kludge a solution for a compiler that lacks a feature (e.g.                 |
|EXECUTE_COMMAND_LINE,  ERROR STOP, etc.)     However, conditional           |
|compilation is rather limited for working around many missing/broken OO     |
|features.                                                                   |
|                                                                            |
|Cheers,                                                                     |
|                                                                            |
|- Tom                                                                       |
|                                                                            |
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|                                                                            |
|                                                                            |
|      -- John Harper, School of Mathematics Statistics and Operations       |
|      Research                                                              |
|      Victoria University, PO Box 600, Wellington 6140, New Zealand         |
|      e-mail john.harper@vuw.ac.nz phone (+64)(4)463 5276 fax               |
|      (+64)(4)463 5045                                                      |
|                                                                            |
|                                                                            |
|Thomas Clune, Ph. D.  <Thomas.L.Clune@nasa.gov>                             |
|Chief, Software Systems Support Office Code 610.3                           |
|NASA GSFC 301-286-4635                                                      |
|MS 610.8 B33-C128 <http://ssso.gsfc.nasa.gov>                               |
|Greenbelt, MD 20771"                                                        |
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