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devel / comp.lang.lisp / Re: How to implement property list

Re: How to implement property list

<844kd02x56.fsf@gmail.com>

https://www.rocksolidbbs.com/devel/article-flat.php?id=16639&group=comp.lang.lisp#16639

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NNTP-Posting-Date: Sun, 11 Jul 2021 19:28:37 -0500
From: sgonedes1977@gmail.com (steve)
Newsgroups: comp.lang.lisp
Subject: Re: How to implement property list
References: <5f58894e$0$10271$e4fe514c@news.xs4all.nl>
Date: Sun, 11 Jul 2021 20:28:37 -0400
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by: steve - Mon, 12 Jul 2021 00:28 UTC

albert@cherry.(none) (albert) writes:

> I finally understand that property lists are much more
> essential to lisp than I thought. Also it seems that
> different properties may not at all be related even if they
> happen to apply to the same symbol.
>
> A naive approach for implementation is :
> - assuming a symbol has a token (probably a memory address or an index)
> - assuming a property has a name.
>
> 1 Establish for each property a hash table of an appropriate length p.
> 2 Use the symbol's token as a hash, probably just index%p .

I would use an alist. the symbols are eq, the property lists should be
small, this is a very fast lookup. the problem is with packages. symbols
get around.

lisp is very fast with list, I use acons ((sym1 (values....))
(sym2 (values... )))

> Would this simplistic approach work?

I would go simpler ..

Subject	Author
Re: How to implement property list	steve