Bertrand Meyer's technology+ blog
Software engineering, programming methodology, languages, verification, general technology, publication culture, and more
The software world is not flat; it is multipolar. Gone are the days of one-site, one-team developments. The increasingly dominant model today is a distributed team; the place where the job gets done is the place where the appropriate people reside, even if it means that different parts of the job get done in different … Read more
More than once I have emphasized here [1] [2] the urgency of rules requiring systematic a posteriori analysis of software mishaps that have led to disasters. I have a feeling that many more posts will be necessary before the idea registers. Some researchers are showing the way. In a June 2009 article [4], Tetsuo Tamai … Read more
In response to many requests, I have made available [1] the slides of my education keynote at ICSE earlier this month. The theme was “From programming to software engineering: notes of an accidental teacher”. Some of the material has been presented before, notably at the Informatics Education Europe conference in Venice in 2009. (In research you can … Read more
In the decades since structured programming, many of the advances in software engineering have come out of non-university sources, mostly of four kinds: Start-up technology companies (who played a large role, for example, in the development of object technology). Industrial research labs, starting with Xerox PARC and Bell Labs. Independent (non-university-based) author-consultants. Independent programmer-innovators, who start open-source communities … Read more
I am blogging live from the “Cloud Futures” conference organized by Microsoft in Redmond [1]. We had two excellent keynotes today, by Ed Lazowska [1] and David Patterson. Lazowska emphasized the emergence of a new kind of science — eScience — based on analysis of enormous amounts of data. His key point was that this … Read more
New variants of the loop construct have been introduced into Eiffel, allowing a safer, more concise and more abstract style of programming. The challenge was to remain compatible with the basic loop concept, in particular correctness concerns (loop invariant and loop variant), to provide a flexible mechanism that would cover many different cases of iteration, … Read more
Thus we are permitted to prove that the unqualified call creates certain aliasings, on the assumption that it starts in its own alias environment but has access to the caller’s environment through the inverted variable, and then to assert categorically that the qualified call has the same aliasings transposed back to the original environment. This change of environment to prove the unqualified property, followed by a change back to the original environment to prove the qualified property, explains well the aura of magic which attends a programmer’s first introduction to object-oriented programming.
In the past few weeks I wrote a program to compute the aliases of variables and expressions in an object-oriented program (based on a new theory [1]). For one of the data structures, I needed a specific notion of equality, so I did the standard thing in Eiffel: redefine the is_equal function inherited from the … Read more
Once again, and we are not learning! La Repubblica of last Thursday [1] and other Italian newspapers have reported on a “computer” error that temporarily brought thousands of accounts at the national postal service bank into the red. It is a software error, due to a misplacement of the decimal points in some transactions. As usual … Read more