Path: utzoo!attcan!uunet!ncrlnk!ncrcae!ece-csc!ncsuvx!gatech!uflorida!mailrus!purdue!i.cc.purdue.edu!h.cc.purdue.edu!ags From: ags@h.cc.purdue.edu (Dave Seaman) Newsgroups: comp.lang.fortran Subject: Re: *THE GENERAL CASE* (was: function side effects) Message-ID: <4003@h.cc.purdue.edu> Date: 22 Sep 88 16:32:33 GMT References: <3999@h.cc.purdue.edu> <3980@lanl.gov> Reply-To: ags@h.cc.purdue.edu.UUCP (Dave Seaman) Organization: Purdue University Lines: 47 In article <3980@lanl.gov> jlg@lanl.gov (Jim Giles) writes: >I have _never_ claimed that side effects couldn't be done in the general >case. Until _you_ claimed that I had, I hadn't even _mentioned_ the >general case! As I have pointed out several times already, and will again in a moment, you have REPEATEDLY claimed that ALL side effects are disallowed. That is how this discussion began. I have quoted the following passage before. This time I am including more of the surrounding context. In article <3659@lanl.gov> you wrote: >No, it doesn't cause the subscript to be evaluated twice. In Fortran >functions are not allowed to have side effects. The compiler will >therefore recognize the subscript expressions as common subexpressions >and will evaluate only once. Even when I quoted this before, you did not take the opportunity to correct your statement and say that you were talking only about a particular class of side effects. The reason was that you were still arguing that a particular special case that I am not allowed to mention here was illegal, and since there was nothing in the standard to support your contention, you had to make the blanket statement that all side effects are illegal. Therefore, you forced me to argue the general case. Otherwise there would have been nothing to argue. >And as for section 1.4 of the standard - I am one of the most >frequent supporters of allowing extensions. As I've repeatedly pointed >out: pointers, 31 character names, bit functions, etc. are all extensions >allowed in CFT77 on Crays - and _NOT_ONE_ of these feartures makes the >compiler non-standard. You are changing the subject again. Extensions are not mentioned in the subject of this discussion, they were not mentioned in the portion of section 1.4 that I quoted, and I have not mentioned extensions at all in this entire discussion, except in one very specific context, which was: In message <3745@lanl.gov> you wrote: >Side effects other than the one you found (which I admitted that I'd >forgotten) _are_ extensions to the standard. All I did was explain that this claim of yours was still wrong, by pointing out a second side effect that is most definitely not an extension. -- Dave Seaman ags@j.cc.purdue.edu