On 25 Jun 2014, at 9:26 , phil@highoctane.be wrote:

On Wed, Jun 25, 2014 at 9:01 AM, Marcus Denker <marcus.denker@inria.fr> wrote:

On 24 Jun 2014, at 21:52, stepharo <stepharo@free.fr> wrote:

> Where which package?
> Because we should track it and publish a new package.
>
>
We should think about have an OrderedDictionary in the base system�

It is very useful indeed. Question: what are the consequences of using OrderedDictionary vs Dictionary? I read the class comment but would welcome some additional info.

Phil

Depends on the implementation, but in general the consequences are worse performance (and potentially memory use) for large (10+ entries? Haven�t benched) Collections.

If it�s done the naive way, as an OrderedCollection of Association with an expanded access protocol, O(n) rather than O(1) access is the big one.

If done with pairing Dictionary/OrderedCollection internally to provide O(1) access, additional memory/insertion/removal overhead.