On Sep 15, 2004, at 2:32 AM, Sebastian Sastre wrote:

> Hi everybody, Avi,
>  
>     for a BTree, a message like
>     
>      >>keysStartingWith: aString
>   
>     that returns a set of keys will be *very* useful.
>  
>     I wonder if anybody has implemented an extension of the available 
> Avi's BTree, or other implementation of your own, that supports this 
> kind of wilcarded key search.
>
>     Avi, any clue of how to extend your BTree implementation to 
> archieve this? I'm stuck and can't figure out how does it work that 
> abbreviations mechanism.

I'm not sure which abbreviations mechanism you mean; if you're talking 
about BTreeStringKeys, don't go there - it's way too messy.  What you 
want to do should be at the node level anyway, and not worry about the 
details of how the keys are stored.

And yes, my BTree class could definitely use some extra iteration 
protocol for ranges of keys and so on.  Maybe I'll find some time today 
to release a new version.

However, for what you're asking, my guess is that the best data 
structure is a Trie.  I was talking to someone recently about this who 
was going to implement one; hopefully he'll pipe up and you can compare 
notes with him.

>     I'm working on an IndexedCollection that uses BTree to support 
> it's indexes. I can make it available when it works.

Cool.

Avi