Subject: Re: Question on the role of :absolute and :relative directories and logical pathnames
From: Erik Naggum <>
Date: Tue, 01 May 2001 17:37:59 GMT
Newsgroups: comp.lang.lisp
Message-ID: <>

* Martin ``rydis'' Rydstr|m <>
> If I understood them correctly, :absolute means "absolute relative to the
> base of the translation for the logical host", whereas :relative could vary
> with working directories and so on.

  Yes, it could, but it has nothing to with that..  :absolute or :relative
  _only_ affect which translation rule applies.  Any meaning you might
  think of is relative to the value of logical-pathname-translations for
  the relevant host, not an absolute.

> PVE> I think that foo:;bar;source.lisp and foo:bar;source.lisp have a
> PVE> different meaning, and that the second can legally be translated (on
> PVE> some unix machine) to /bar/source.lisp. Irrespective of where the
> PVE> logical pathname foo points to.
> No, I don't think it could. Or, well, maybe it /could/, but that'd be a
> rather extreme reading of a vague spec. (Based on what I have been able
> to glance from the HyperSpec.)
> You define the translation, both for relative and absolute logical
> pathnames, and I see very little point in having the implementation not
> care about the translation for the "absolute translation".

  Well, actually, in a pathological translation rule, you _might_ get that
  result, but then it would be intended by the programmer.

> Logical pathnames seem very interesting, but every time I try to really
> understand, I get either very confused or very disappointed.

  The problem is probably that you don't view them sufficiently abstractly
  but want to _do_ stuff with them.  This generally fails.  They are like
  URLs: don't say squat about anything specific, but are just "locators"
  and depend entirely on the translations for their meaning.

  I found no peace in solitude.
  I found no chaos in catastrophe.
			-- :wumpscut: