Re: [Haskell-cafe] ANN: unordered-containers - a new, faster hashing-based containers library

On Sat, Feb 19, 2011 at 3:04 PM, Johan Tibell wrote:

On Sat, Feb 19, 2011 at 11:58 AM, Louis Wasserman wrote:

...

A couple thoughts: size takes O(n).  That's just depressing.  Really.

This applies to all the container types. We could support O(1) size at the cost of slowing down e.g lookup, insert, and delete a little bit. I haven't measure how much yet. Would it be worth it?

Getting a bit picky, but for the record, Data.Map and Data.Sequence provide O(1) size, and Data.HashTable I believe stores the information but doesn't expose it from its tiny API. That's not an argument either way for what a HashMap should do, however :-) Cheers, Sterl.