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Re: my kingdom for a hash table!

Ben writes:

> Amy writes:

>> In MOOSE, I'm using hash tables for verb lookup for in-db parsing.
>> I implemented this by having each hash slot be a property on the
>> object.

> If you don't like that, keep in mind that:
> 	object.(propname)
> is almost exactly the same as:
> 	values[propname in keys]

...right now, at least.

> I would have to do some experiments to determine which one is faster,
> but in most situations I would expect them to be very nearly equal.
> Both are linear searches, of course, 

It will be a lot easier to make `object.(propname)' run faster than
`values[propname in keys]', and there are plenty of incentives to
expend effort there.  For that reason, I'd prefer the propname

As Amy mentioned, keeping lists reasonably short is probably a good
thing.  Somebody with more time for exposition for me should detail

> but take advantage of the fact that it's a linear search in C code
> rather than any other kind of search in MOO code.

The other advantage that `object.(propname)' takes advantage of is
that it will be working with relatively short string-valued keys; it
can make sense to avoid strcmps by trying hashes first if strcmp isn't
heavily optimized by your C compiler.  As Ben notes this clearly calls
for experiment rather than guesses pulled out of a hat.
Jay Carlson

Flat text is just *never* what you want.   ---stephen p spackman

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