Issue: PATHNAME-SUBDIRECTORY-LIST, PATHNAME-COMPONENT-CASE, PATHNAME-WILD

[David A. Moon <Moon@STONY-BROOK.SCRC.Symbolics.COM>]

    Date: 19 Sep 88 16:23 PDT
    From: masinter.pa@Xerox.COM

    I think it might be worthwhile to organize the pathname issues by operating
    system, e.g., What's the right way for CL to talk to Unix-like file systems?
    What do you think?

I think that focussing the pathname issues by using specific operating
systems as examples is a great idea.  I think that prescribing in the
Common Lisp spec how specific operating systems are to be treated is
possibly a good idea, but has some potential problems -- it makes the
Common Lisp spec dependent on specific operating systems that might
change out from under it; it might overspecify something that should
have been left to the discretion of implementors, in overreaction to the
present situation; it might encourage users to write nonportable
programs by paying attention only to the part of the spec for the
operating system they happened to develop on, ignoring the more general
portability concerns.  These problems are not fatal if handled right.

I'm certain that handling each operating system in isolation, with no
coherency among them, is a recipe for disaster.  It could increase
portability among multiple implementations on a single operating system,
but further damage portability between differing operating systems.
Unless you believe that no operating system but Unix will survive,
this would be doing no service to the users of Common Lisp.

I think this implies that you can't duck the PATHNAME-COMPONENT-CASE
issue so easily: you can't just say that each operating system can make
an individual choice.

Whether this will go over politically is difficult to judge.  It didn't
work at all in 1983-4.