pathnames [Re: files, printers, etc. [Re: The feel of a Lisp
Alaric B. Williams
Sat, 10 May 1997 10:49:45 +0000
> Alaric B. Williams:
> ;; (*employees* 'pictures #(picture of Lionel))
> ;; (*employees* 'names "Lionel B. Snell")
> ;; (*employees* 'surname "Snell"
> ;; Those are source code. My syntax is designed as what the user types in -
> Trust me - if that's a syntax for an end-user (i.e. NOT a lisp
> programmer), users won't want to go anywhere near the machine.
> An end-user is not going to be able to make sense out of that - they
> don't want to know LISP quoting rules, and they probably don't want to
> know LISP syntax at all.
Perhaps middle-user is the right term - the kind of person
who would use UNIX shells. Indeed, a true end-user would,
like you say below, never touch pathnames!
In this case, the employees database filer has to register itself
with the pathname manager, rather than just leave a "path" object
in the user repl environment called *employees*. Which has it's
pros and cons.
But to define a more formal semantics, a filer registers itself by
putting a path object in the appropriate environment such that it
reads it's arguments from left to right as a hierarchical subdivision
of itself, which may even be cyclic.
Thus, the syntax isn't unusual. We still quote symbols, unless we
/mean/ a variable reference.
The make-path function looks at a list, which must start with a path object,
and passes the rest of the list to the dereferencing function in the path
object, and returns the result, which is another path object.
(make-path (*employees* ...))
is the Lisp source to parse said path.
That's a string. Representing things as strings when they are really lists
is a UNIX trick :-(
> Better yet, don't make them type paths at all. Write an integrated
> file system/OOFS/POS/Object browser with drag and drop. I almost never
> type paths by hand anymore in my everyday computer usage.
Me too, but the underlying CLI thing is important for Real Men (tm) to
Alaric B. Williams (email@example.com)
---<## OpenDOS FAQ ##>---
Plain HTML: http://www.delorie.com/opendos/faq/
Fancy HTML: http://www.deltasoft.com/faq0000.html