Left-bias and non-structural equality.

[Jean-Philippe Bernardy]

On 1/8/06, Adrian Hey <ahey at iee.org> wrote:
> On thing that occurred to me was that calling the AVL tree based sets
> "Set" might be the wrong thing to do anyway. If we want to allow for
> future implementations to be based on other data structures then we
> probably shouldn't usurp the name "Set", but rather call it SetAVL or
> something. (To allow a consistent naming scheme to be used if someone
> ever produces SetRedBlack say). Both SetAVL and SetRedBlack would
> be instances of the "Set" type constructor class (presumably).
>
> So maybe the thing to do would be to keep Data.Set (with biasing specified)
> for the present, but just put a pointer there in the Haddock to a new
> module Data.SetAVL (which does not specify biasing). This scheme would
> also allow the current Set implementation to be retained if it turns
> out to have some advantages over AVL (seems a bit rash to discard it
> completely anyway), but it would be called Data.SetAdams (or something..)

As I was writing to Adrian this morning, that's exactly what I am proposing. :)

To clarify things, I've put up some more explanations on the wiki:

http://haskell.org/hawiki/StandardCollectionLibraries

Cheers,
JP.