pathnames [Re: files, printers, etc. [Re: The feel of a Lisp
Alaric B. Williams
Tue, 6 May 1997 21:36:15 +0000
> >> I think this is subtley locking yourself into a particular paradigm of
> >> a Unix style tree structure.
> >Not necessarily - the only thing I am asserting here is that groups
> >of objects may contain groups of objects. Those symbols, that
> >reference objects inside groups, could be anything - a group of
> >large-number prime factorisations,
> Well groups within groups is a tree structure by definition.
Not quite... it's a directed graph, IIRC - for a group can
be in itself and all that.
> Yes, so if you want to use pictures as identifiers that implys that
> there could be several algorithms for getting at the object you
> want. It might be you want to get objects by name, by colour, by
> description, by location etc. So a simple (foo bar baz) meaning "the
> baz object in the bar collection in the foo collection" is not enough
You could write:
(*employees* 'pictures #(picture of Lionel))
(*employees* 'names "Lionel B. Snell")
(*employees* 'surname "Snell"
The directory objects "pictures", "names", and "surname" are all in
fact accessors for one database-like object.
> >> >((.) Hello!)
> >> If you want a CWD you can just store one in a variable.
> >That's what the . was, rather than a global concept... just a standard
> Well if it's a standard then that kind of implys a global
> concept. Perhaps I don't understand you right.
I don't explain myself too well, I'm afraid. The . is the idenitifier of
a variable, yes; just in line with the UNIXy convention, this particular
person has called his PWD "."!
> >The CWD is really only a user-level concept anyway; it only complicates
> >programming tasks IMHO.
> >=> a new syntax:
> >(make-path *internet* "abwillms.demon.co.uk" 'Public 'Hello!)
> You're still assuming simple tree structure with a single key for
> getting at your objects.
But no :-)
Alaric B. Williams (email@example.com)
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