Damien Cassou wrote:
> What don't you like? If I have no feedback, I can't improve and learn.

One of the things that I personally don't like is that you seem to be 
repeating the same conceptual mistakes of the original library. For 
example, what is the *conceptual* difference between an 
NSReadableCollectionStream and an NSWriteableCollectionStream and an 
NSReadWriteCollectionStream? These seem arbitrary (and not very helpful) 
distinctions that would be better modeled by having a single 
NSCollectionStream which -if that is really necessary- has an attribute 
controlling whether it's going to be used read-only or not.

If I were to rewrite streams I'd actually start at a different point. 
Not by making these micro-distinctions about readability and writability 
(which seem to make up most of the traits in the version that I looked 
at) but rather define three basic types of streams:
* Internal streams: Which are collections+cursor, providing the full 
collection interface to streams (which is hugely useful).
* External streams: Which are modeling I/O (so they are potentially 
infinite sources, can block, are often asynchronous etc)
* Translating streams: Which are streams that perform operations on 
other streams (CRLF conversions, compression, decompression)

If you were to structure a stream library along these lines I think 
you'll find that most of the uses for traits would go away because 
besides the core protocol (which would appear in class Stream) there is 
actually very little duplication of responsibilities in there.

Cheers,
   - Andreas