On Sat, 30 Nov 2013 16:55:58 -0600, Anthony Babonas wrote: >Don't forget the hyphen and x'C0'. > Hyphen is strange. JCL allows hyphen in data set names in some contexts; reports it as a syntax error elsewhere. I believe this is documented.
ISPF LM services allows hyphen in member names in some contexts; reports it as a syntax error elsewhere. Is there any rationale for this erratic behavior? Conway's Law? I understand that x'C0' was a mistake. A coder wrote some sequence of CVD and UNPK, forgetting to repair the sign nybble (perhaps in SVC numbers?) It was immediately recognized as too deeply embedded to repair, and institutionalized. I'm not an assembler programmer. Mentally, I can't envision the exact instruction sequence or should have been. With a brief exposure to MVS, I started to learn CMS. I was shocked (briefly) to learn that file names might begin with numeric digits; in fact be entirely numeric. Why not in OS/360 data set names? In an era of severe storage and CPU cycle constraints, the lexical analyzer would have been simpler for not needing to treat the first character specially. Would allowing numeric data set names have introduced a syntactic ambiguity in JCL or elsewhere? Member names couldn't unambiguously be numeric because of GDG levels. Earlier in this thread, someone did some arithmetic showing that the current data set name conventions allow more data sets than could be stored on any current or reasonably envisioned volume. Therefore there's no rationale for enlarging the name space. Beware such arguments based on name space cardinality -- I suspect that there would be enough available data set names if only letters in the first third of the alphabet were permitted, so why allow any more? Becayse some programmers like the flexibility. I would like the flexibility of lower case alphabetics. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
