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Re: Scheme style auto-resizing hashtable (fwd)



On Fri, 6 Nov 1998, Maciej Stachowiak wrote:

> 
> jglascoe@jay.giss.nasa.gov writes:
> > 
> > so what do I have here?  "dictionary" and "meaningful identifiers". hmm.
> > I also considered using "hash-table" (used by CL, so I just said "No."),
> > "assoc-array" (one letter longer than "dictionary", you lose), and even
> > "auto-hash" (where did that come from?).
> > 
> 
> A dictionary could be implemented as a hash table, an association list,
> a procedure, a red-black tree, an AVL tree, a B-Tree, an ordered
> association list, etc. To reserve the name `dictionary' for the
> hashtable implementation seems arrogant to me. 
> 

the great Larry Wall wrote that the three virtues of a programmer are
hubris, laziness, and impatience.  I believe all Schemers on this mailing
list are guilty on all three counts (some more guilty than others,
perhaps).

I say this: the whole dictionary => ordered entries concept is more than a
little tenuous.  If, at sometime in the future, somebody writes a
collection type data structure with ordered elements, then I propose they
name the type either "ordered-collection" or "telephone-book"!

On Mon, 2 Nov 1998, Jay Glascoe wrote:

> On Tue, 3 Nov 1998, Tel wrote:
> 
> > Hash tables don't maintain order of the keys. Dictionaries are in 
> > alphabetical order (last time I looked at a paper one was a while
> > back).  You have to be a little bit careful when freely associating
> > concepts. 
>
> I don't want to keep my entries ordered!
>
> but is "ordered entries" really an integral attribute of dictionaries? 
> Aren't paper dictionaries ordered because people can't hash the word
> they're looking up in their heads?  Or is e.g., "aardvark" somehow
> related to the Aare River in Switzerland? 

ah yes, the old "aardvark" related to the "Aare River" argument.  But
"telephone-book", now we're talink!  "Hansen, James" IS probably related
to "Hansen, James Jr.".

"telephone-book", *telephone-book*, TELEPHONE-BOOK !!

> > "last time I looked at a paper one was a while back"
>
> right, on-line
> dictionaries can internally store their entries in whatever order they
> darn well please.  Does this make any difference to the user?  Does this
> make, e.g. http://www.m-w.com/ not a *real* dictionary? 

ah, but there aren't many on-line telephone books, now are there?

> I'll comment on the latest revision of your suggested API in a later
> message.
> 
>  - Maciej
> 

as always, thanks for your input Maciej.

BTW, how about simply "table"?  that's what Dylan calls its hash tables.


	Jay Glascoe
	jglascoe@jay.giss.nasa.gov


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