Domain Driven Design is different, Object Orientation means not to code but to model. OO-Languages are modeling languages, not programming languages. Spread the word!

ddd (application/zip, 431 KB)

... ask J.B. Goodenough, also note his mention of preconditions ("domain failures") and postconditions ("range failures").

The paper is not accessible for free (ACM account needed), but I've found a nice piece of summary of exception history (application/pdf, 141 KB) : In the Communications of the ACM in December 1975, John B. Goodenough discussed issues in exception handling, classifying the types of exception usages as (i) dealing with domain or range failure of an operation (ii) indicating the significance of a result, or (iii) permitting monitoring of an operation. When range failure is indicated, the operation may need to be aborted, retried or terminated yielding partial results. A domain failure requires modification of the input or an abort of the operation. Exception type (ii) is not a range failure, but requires that additional information be passed back to the user about the operation. Exception type (iii) is usually resumed after the user examines the information about the operation passed back by the exception. Not all of these are error conditions; Goodenough described them “as a means of conveniently interleaving actions belonging to different levels of abstraction” [6]. After reviewing some existing exception mechanisms of the time, Goodenough discussed requirements for good exception handling, which should ”help prevent and detect programmer errors” according to Gannon and Horning [4]. He argued the effectiveness of lexical (or static) association of handlers with operations that may throw exceptions. These included both language-defined and user-defined (subroutines) operations, with explicit declaration of those exceptions that may be thrown as the result of a call. He advocated compile-time checking of the completeness of exception handling. His model of exception handling included the possibility of resuming execution as well as termination, and allowed the use of default exception handlers. Related: I'm reading currently about Components, I was fascinated by the notion of security facade, and expert components that handle a diagnosis and recovery interface of the core component. Could this be a architecture principle developers should follow? It seems not so popular in these days, but JEE handles these issues somehow...

what an interpretation!

Una Furtiva Lacrima (G. Donizetti)

Una furtiva lagrima negli occhi suoi spuntò... quelle festose giovani invidiar sembrò... Che più cercando io vo? M'ama, lo vedo. Un solo istante i palpiti del suo bel cor sentir!.. Co' i miei sospir confondere per poco suoi sospir!... Cielo, si può morir; di più non chiedo.

Eccola... Oh! qual le accresce beltà l'amor nascente! A far l'indifferente si seguiti così finché non viene ella a spiegarsi.

ABSTRACT: Communication via electronic media of dissemination, Niklas Luhmann assumes in his book Die Gesellschaft der Gesellschaft (1997), is not only different from communication via other media of dissemination, most notably language, writing, and the printing press, but it is also forcing the society to change both its structure and its culture by catastrophically presenting the society with a new overflow of meaning. There is an overflow of data with no hints at to which actions and intentions might lend it accountability. Mediated via the screen, presenting us with a new relation between surface and depth, known before only from religion (and art), communication becomes dependent from structural couplings with an "invisible machine", which add to those structural couplings traditional societies entertain with spirits, ghosts, and gods, and modern society entertains with human consciousness. The present paper is trying to emphasize Luhmann's original insight and to look at the two arguments this insight consists of.

homepage.mac.com

A meditation over a funny manual sentence 'Assembly of Japanese bicycle requires great peace of mind' in »Zen and the Art of Motorcycle Maintenance« reminds me of the intend of the original MVC paper by Trygve Reenskaug - the subjective immersion you should feel when operating an application: The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed. The test of the machine is always your own mind. There isn't any other test - Robert M. Pirsing; Zen and the Art of Motorcycle Maintenance; Chapter 14 By the way, MVC plays the same immersion argument Jeff Bezos brought up for the Kindle design: "books should disappear when they are red"