Lambda the Ultimate

F# 1.9.1 has been released with a bunch of new features. LTU readers would probably be interested in the work on unifying object oriented and functional code:

# Active Patterns. Active patterns give a form of extensible pattern matching on abstract values. F# active patterns allow you to pattern match against .NET object values such as XML, System.Type values and LINQ Expression trees. In this redesigned version they become an official part of the language and some novel additions give a lightweight and non-intrusive mechanism to both partial patterns, parameterized patterns and "complete" decompositions (views) of types.

# Implicit Class Construction. This lovely feature makes writing classes considerably more succinct and helps to further bridge the gap between type-inferred functional programming and object-oriented programming.

More info is available at Don Syme's blog here.