Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!unmvax!brainerd From: brainerd@unmvax.unm.edu (Walt Brainerd) Newsgroups: comp.lang.fortran Subject: Re: Two Fortran Standards Message-ID: <308@unmvax.unm.edu> Date: 28 Aug 89 04:31:28 GMT References: <1598@convex.UUCP> Organization: University of New Mexico at Albuquerque Lines: 71 In article <1598@convex.UUCP>, psmith@mozart.uucp (Presley Smith) writes: > > Okay Walt... If Fortran 8x contains ALL of F77 as a subset, why did the > committee vote at the February meeting, 32,0,2, to change the introduction > of the proposed standard, introduction page i line 7 and 8 > > FROM: > > "Any standard-conforming FORTRAN 77 program is standard > conforming under this standard, with the same interpretation." > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > TO: > > "Any standard-conforming FORTRAN 77 program is standard > conforming under this standard." > > Gives one a real warm feeling that if a program is standard conforming > under FORTRAN 77 it will execute under Fortran 8x, BUT it's POSSIBLE that it > will get a different answer or that the programmer will have to change > the program to get it to execute in the same manner as it did on FORTRAN 77. > Hum... "Fortran 8x contains ALL of F77 as a subset" you claim? Read on... > Page i is not part of the standard, so it doesn't matter, but I don't know why it was changed. Page 1-2 of the STANDARD, lines 37-39 say "Any standard-conforming Fortran 77 program remains standard conforming under this standard, with the same interpretation;" ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ so I guess we don't have to worry about that one. > What about the vote in X3J3 on Document 58, 111-RRR-12, "Extra Precision > option for DATA statement", that was DEFEATED on a role call vote by 24-13? > To quote from document 111-RRR-12: > > "The committee (X3J3), in a previous action, REMOVED the Fortran 77 > permission for processor to supply extra precision. > > Comment 338.44 deplores the "extra precision" feature of Fortran 77. > > Comment 518.24 suggests that the Fortran 77 rule must remain in order > to be UPWARD COMPATIBLE from Fortran 77. In particular, standard > conforming programs executing on standard conforming Fortran 77 > processors will NO LONGER EXECUTE the same way in Fortran 8x. > Distasteful as the rule may be the committee should recognize that > removing it creates this situation. If this is the intent, it > should be explicitly stated." > I personally was in favor of retaining the F77 wording for just the reasons stated, so perhaps we do agree on one thing. However, in a legalistic sense, it is editorial because there is nothing in the standard the controls anything about how much precision a real number has. Though there is the possibility that some implementor could use this as an excuse to change somethine, there is no requirement to do so and I doubt that anyone would > > Still think "Fortran 8x contains ALL of F77 as a subset"??? How many > other examples are there? NO ONE KNOWS! > So far we have zero examples. > > Walt and I seldom agree on anything... BUT, I certainly agree with him on > this... It's a kludge and a mess! I guess we still don't agree on this. My words were that it is NOT a kludge and a mess, but some parts of it are. -- Walt Brainerd Unicomp, Inc. brainerd@unmvax.cs.unm.edu 2002 Quail Run Dr. NE Albuquerque, NM 87122 505/275-0800