Friday, May 14, 2004

Method invocation order for multiple inheritance junkies

Michele Simionato explains the C3 algorithm for Method Resolution Order as used in Python 2.3.

Those not interested in same might like to take a look simply to marvel at the ASCII art.

Method invocation order for multiple inheritance junkies

Michele Simionato explains the C3 algorithm for Method Resolution Order as used in Python 2.3.

Those not interested in same might like to take a look simply to marvel at the ASCII art.

Method invocation order for multiple inheritance junkies

Michele Simionato explains the C3 algorithm for Method Resolution Order as used in Python 2.3.

Those not interested in same might like to take a look simply to marvel at the ASCII art.

Thursday, May 13, 2004

Message exchange, stateless services and Domain Specific Languages in Service Oriented Computing

Via Radovan Janecek comes this interesting 3 page PDF Microsoft's Next Frontier.

Loose coupling via stateless, message oriented interactions. Yummy. Domain Specific Languages. Doubly yummy.

As I see it, C# and Java are today's assemblers. Speed of application delivery trumps speed of application execution 99 times out of 100 (welcome to capitalism). Then there is Moore's law. Add them together and I think its likely that the action will move to DSLs (Domain Specific languages0 that target the VMs for those two runtimes).

DSLs that allow developers to work naturally with documents as first class "objects" (for want of a better word) are required. In years to come, I hope we all collectively cringe at todays crop of Event/Pull/Tree/Marshalling abstractions for XML processing. LAML, xduce and HaXML offer tantalising glimpes of where we might be headed. (I predict lots of GUIs fronting these things).

DSLs that allow "event driven" business process description. PI-Calculus is on everyones lips but don't forget Petri-nets or even plain old Finite State Machines.

DSLs that embrace the dynamic typing implicit in moving "type checking" away from objects/records and into document types (grammers). (Jython for dynamic typing, maybe something like Haskell's polymorphic types with some sort of native type for Tree Automata ) for those who want compile time document type validation.

DSLs that cross-translate to XML (XNFs = XML Normal Form:-) but provide human-oriented grokkable syntaxes. RelaxNG Compact Syntax leads the way but I predict the XUL's/XAML's of this world will follow suit.

Wednesday, May 12, 2004

More JVM languages

I visited http://grunge.cs.tu-berlin.de/~tolk/vmlanguages.html for the first time in a while and lo! a bunch of new languages for the JVM have been added.
The description of Aardappel (of which I know nothing) caught my eye:

    Aardappel is a new language, which computes by concurrently reducing trees (using a form of tree-rewriting) which sit together in tree-spaces (bags) and communicate amongst eachother (exchanging parts of themselves, in Linda-like fashion), and in general having a jolly good time alltogether. The language is 100% graphical. Oh yes, the language is linear as well.

Any language that works by having a jolly good time alltogether has to be worth checking out right?

PYX and .NET

I recently contributed a couple of XML hacks to an upcoming O'Reilly book XML Hacks.

As a consequence, I got to pick a bunch of O'Reilly books which arrived today.

Flicking through .NET and XML and what do I see? The PYX notation being used to illustrate .NETs XmlReader model.


Tuesday, May 11, 2004

The demise of Hara-Kiri programming

"Error handling" as we techies call it, should not be confused with "error recovery", "robustness" or such like. No, error handling as practices in the trenches is all about honour. Catch an error condition and then, with all the grace you can muster, fall over.

The demise of hara-kiri programming is an ITWorld article about error handling in these increasingly decentralised (read "web services") days.

Evolution of a Haskell programmer

Evolution of a Haskell programmer. Both funny and educational. Whats not to like?

Sunday, May 09, 2004

Spam, liquid market securities and DOS attacks

If you are a geek in search of of reading material that is eclectic, challenging and endlessly fascinating look no further than Nick Szabo.

Nick's latest offering A scarce object economy combines a security model , a micropayment system and an automated currency hedge mechanism that enables Joe Public to use sophisticated financial engineering at low cost.