Errr try fixing a program that uses alter at 0300. Nothing is clear through gritty eyes at that time of the AM. A company I worked at a while ago. I put in the standards manual never use ALTER and every team leader wanted it emblazened across every programmer forehead.
Ed > On Jul 14, 2016, at 1:28 AM, Bill Woodger <[email protected]> wrote: > > Why has ALTER always been bad? Because of the potential scope of things that > you can do with it, or because COBOL programmers will ignore or be unaware of > any "best practice" for using it, or something else? If either of the first > two, then away goes "EXIT PARAGRAPH/SECTION" into the bad-boys-bucket. > > If the last, please elucidate, but remembering the context of the time. Bear > in mind also that it was likely not invented out of thin air for COBOL, so > likely "best practice" in programming at the time of COBOL's development. > > I'm not suggesting the use of ALTER (that would be regarded like suggesting > that faeces are added to your breakfast cereal), or even GO TO ... DEPENDING > ON ..., or even GO TO, or NEXT SENTENCE, or the new EXIT formats. > > I am suggesting the historic record and current observable practice seem to > indicate that the new EXIT formats will be (ab)used and new forms of minor > chaos will ensue. > > At that point, I'm not going to sit back and tell you "I told you so". I'm > telling you now :-) > > We can attempt to ameliorate with "best practice for the use of new forms of > EXIT (if you really feel you must use them)". > > To me, "structured programming" is not limited by the availability of > language constructs for "structure". For too many, present company excluded > until known otherwise, simple using structured constructs does not make a > program "structured". > > "Here's EXIT PERFORM, that looks like a construct in another language that is > regarded as an aid to structured programming, so I'll use it, then my program > will be structured". Similar to "But my program works, it uses INITIALIZE > [when of course it doesn't, and the INITALIZEs are all of fields whose > contents are replaced by the next line of code]", or "I got a clean compile > but somehow my program doesn't work". > > Of course, anyone can say anything bad they like about ALTER, and get away > with it, as it is hated. Same with COBOL. As well as "external myth" there's > self-generated internal myth (like S0C1 for reading a file which is not open, > and many, many others). > > On Thursday, 14 July 2016 06:35:39 UTC+2, Edward Gould wrote: >>> —————————————SNIP------------------------------------ >>> ALTER is bad because its not obvious when you look at a piece of code where >>> it might actually branch to. >>> >> >> >> Alter has *ALWAYS* been bad. >> >> Ed > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
