[ZODB-Dev] OOBTree: Persistent Objects as keys

Toby Dickenson tdickenson@geminidataloggers.com
Wed, 20 Feb 2002 10:05:28 +0000


On Tuesday 19 February 2002 5:39 pm, Jim Fulton wrote:

> There would also be a registry for registering handlers
>for standard types.

Hmm. You are suggesting that the registry/interface is used to derive a 
2-parameter comparison function, right?

We would have to pass *both* objects through the registry/interface, and only 
proceed if both objects being compared use the *same* comparison function. 
Raise an exception if they use a different comparison function.

Then we need to provide several standard comparison function for the standard 
orders: integer_number_order, plain_string_dictionary_order, etc. Each 
function proceeds by converting both of its operands into the canonical 
representation for that order (using long(), str(), etc) and comparing those 
using the standard cmp().

I dont see any problem with that.