From leslie.polzer at gmx.net  Tue Apr 29 20:38:08 2008
From: leslie.polzer at gmx.net (Leslie P. Polzer)
Date: Tue, 29 Apr 2008 22:38:08 +0200 (CEST)
Subject: [fset-devel] Map functions
Message-ID: <64196.88.73.225.14.1209501488.squirrel@mail.stardawn.org>


Hello,

first, let me sketch my problem:

I need to manage an ordered inventory of things with a fixed number
of slots (in the general sense of the word).
Adding new things is mostly done by assigning them to a slot, but
it would be nice to be able to just say "add this item" whereupon
it will be stuffed into an arbitrary free slot.
For removal the same rules are in effect.
Slots can be empty, accessing them should return NIL.

I have found the MAP type to be most appropriate for this, but
I'm running into problems. For example, there's no
SETF expander for WITH2, thus rendering ADJOINF non-functional
for MAPs. Also, I haven't found any way to find/remove elements
in the image of the map, all operations seem to work on the domain
only.

Can you help me?
Should I subclass MAP or another collection type?

  Leslie

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