G'day all. As some of you know, I'm hacking up Edison. I'd like some suggestions on namespace issues. Note that at the moment, "Edison" has its own top-level name in the libraries document, and I'm happy for things to stay that way for now. First, an overview. Edison is a library of data structures, based around three main concepts: - A Sequence is any container where order is maintained (e.g. stacks, queues, deques, lists etc). - A Collection is a container where order is not maintained, or rather, is maintained by constraints on the ADT (e.g. sets, bags, priority queues etc). - An Association is a container which maps some key type to some data type (e.g. search trees, hash tables etc). The main feature of Edison which distinguishes it from other data structure libraries is that you do not choose data structures by the set of operations which you can perform on them because, for example, all Sequences support the same set of operations. Instead, you pick your data structure by implementation, and live with the fact that some operations are going to be slow on some implementations (e.g. snoc on simple lists is O(n)). Clearly, this is suboptimal. From a programmer's perspective, I shouldn't have to remember the difference between a BinaryRandList and a JoinList. Hence, I have started to implement what I call "facade" types, which wrap underlying implementations to give them names which better reflect what they are used for. Rather than use an Edison.ListSeq, you use an Edison.Stack and use meaningful operations like push and pop rather than cons and tail. I also want to support concurrently accessible data structures, embedded in the IO monad, which will probably be implemented as wrapper functions on top of channels or ports. So now there are three kinds of ways to look at a data structure: - As a concrete implementation - As a facade, exposing those operations that it is optimised for - As a concurrently accessible abstraction The simplest namespace would be something like this: Edison -- Top-level modules may include: Prelude Sequence Collection Association Facade -- Need a better name Stack Queue Deque FiniteMap FiniteTrie Concurrent Stack Queue Deque FiniteMap FiniteTrie Impl Sequence BraunSeq MyersStack Collection SplayHeap BalancedSet BalancedBag Assoc PatriciaLoMap Another option is to dump everything in "Facade" into the top level, but presumably that would require everything in Concurrent to be in the top level too which seems to pollute the top-level namespace a bit too much. Thoughts? Cheers, Andrew Bromage