[plt-scheme] Weak hash tables

Robby Findler <robby at cs.uchicago.edu> writes:

> Perhaps surprisingly, I had an opportunity to implement a trie a few
> months ago and populated it with a 264k word dictionary. 

I guess some people have more opportunity than others.

> I found it went about twice as fast if the children were held in a
> hash-table, rather than in 26-element array (in mzscheme and I heard
> from others that the same was true in Java). I was surprised (I had
> tried the array first), but I guess it just reminds us that there
> are a lot of factors that go into performance. I have no idea what
> they are in this case, tho. :)

Something weird is going on here.  Since a hash table is generally
*implemented* as an array, how could it be *faster*?