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Implementation issue? (re proplist on keyword)

| Date: 5 Dec 1985  01:17 PST (Thu)
| From: Doug Cutting <DOUG@SU-CSLI.ARPA>
| Subject: Bad to hang properties off keywords to install their semantics
|     Date: Thursday, 5 December 1985  00:20-PST
|     From: Rem at IMSSS
| 			[...] it takes a long time each time you use that
|     keyword for the function to scan down the keyword's property list
|     looking for the one item that tells this particular function what to
|     do while ignoring all the other properties that are used by other
|     functions. [...]
| This seems like an implementation issue and has little to do with
| what the language standard should be.
Common LISP has already gotten into the implementation mess here by
insisting adamently that a property list MUST be an alternating list
rather than an ASSOC list or a hashtable etc. Since we've forced the
implementor to make it a linear list of a given format, we ought not
to then encourage LUSER programmers to mis-use it by hanging one
property per function off this one poor daisy-chain
(linear-liked-list) so that the ensemble of such additions in a large
system makes simple functions run very slow searching down that list.