simple-observer
===============

This is a Haskell implementation of the Observer design pattern [1,2],
providing a typeclass and an example implementation (Synchronous)
which is perfectly usable in its own right.

This package is based on Observable.hs by Bastiaan Heeren [3],
originally published as part of an exercise [4] for his students.  It
has been modified, extended and packaged by Andy Gimblett [5,6].

TODO
----

* Implement a mechanism for removal of observers.  Consider Tom
  Lokhorst's suggestion on haskell-cafe [7].

Changelog
---------

2009.11.11 v0.0.1 - first release, renamed from observer to
                    simple-observer in recognition that there are more
                    sophisticated ways to skin this particular cat.

2009.10.30 v0.0.0 - first Cabalised version, unreleased.

--

[1] Gamma et al: `Design Patterns: Elements of Reusable
    Object-Oriented Software', Addison-Wesley, 1994.
[2] http://en.wikipedia.org/wiki/Observer_pattern
[3] http://people.cs.uu.nl/bastiaan/
[4] http://www.cs.uu.nl/wiki/bin/view/Afp0607/ExerciseWXHaskell
[5] http://www.cs.swan.ac.uk/~csandy/
[6] email:haskell@gimbo.org.uk
[7] http://www.haskell.org/pipermail/haskell-cafe/2009-November/068915.html