Ralf's Sudelbücher

While pondering about how to get a grip on software architecture, I now and again of course stumble upon questions on communication between distributed software parts. WCF then springs up as the state-of-the-art technology to answer those questions. But more and more I´m asking myself: Is WCF all there is we need to know about communication in distributed software? Is it the holy grail with its beautiful abstraction over SOAP, WSDL, COM+, HTTP, MSMQ etc.?

In der nächsten Woche, am16.1.2006, beginnt wieder die traditionelle OOP Konferenz in München: http://www.oopconference.de

To refresh myself from obscure information models like Pile and restless thinking about software architecture I decided to pick up a new hobby: compiler construction ;-) Or rather I decided to apply my long time interest in this topic to a good cause: When I talked to Niklaus Wirth - the father of Pascal - in November at the iX conference he told me, he was about to release an updated version of his book "Compiler Construction" (read the complete book here: [PDF]) - which happens to be one of my all time favorite computer text books.

I fired a little too fast when I did my previous posting. Although I wouldn´t say what I wrote is wrong, I´d say it´s not in proper shape yet. There are quite some aspects (sic!) to take into account concerning software design and I´m not yet satisfied with what I have. Software Cells and Software Universe was a good starting point, they help a lot in practice - but still they are limiting and need to be refocused. So for the moment you should forget about the "Classifyiing bubbles" part of the previous posting, where I introduced very concrete levels of abstraction for software. They are not entirely wrong, but I´d like to present them differently in the future. However, I´m still content with the new emphasis I put on edges! They will become even more important today.

I keep hearing, services (as in SOA) are about edges. If that´s the case, what are these edges connecting? There are no edges without vertices.

Ok, finally - after another digression on Pile fundamentals (and I guess, more needs to be said, but not right now) - I´ll quickly describe my prototype implementation of a Pile engine as well as a Pile agent/client to use it for searching in plain text files.

After some philosophical digressions now on to "More matter, less art" as Hamlet´s mother says. Lets step up the ladder of abstraction and look at how to put the elementary particle, those associations, to some tangible use. How about implementing a little full text search application? That´s what I did to check my understanding of Pile. Although there exists such an application at pileworks.org, I thought it would help me more to try to build it myself instead of just studying existing code.

In my previouse posting I´ve described the Pile view of the "world of data": focus on associations, not data. Todays I wanted to put meat on this theoretical skelleton and show you code I wrote. But first let me insert a little philosophical deviation. It might help to distinguish Pile from other (more or less novel) approaches to "data management" - and either draw more fire from the RDBMS camp or drive them off altogether :-) We´ll see...