Design by Contract
Smaller, better textbook
A new version of my Touch of Class [1] programming textbook is available. It is not quite a new edition but more than just a new printing. All the typos that had been reported as of a few months ago have been corrected. The format is also significantly smaller. This change is more than a … Read more
More expressive loops for Eiffel
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
Just another day at the office
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
“Touch of Class” published
My textbook Touch of Class: An Introduction to Programming Well Using Objects and Contracts [1] is now available from Springer Verlag [2]. I have been told of many bookstores in Europe that have it by now; for example Amazon Germany [3] offers immediate delivery. Amazon US still lists the book as not yet published [4], but … Read more
Contracts written by people, contracts written by machines
What kind of contract do you write? Could these contracts, or some of them, be produced automatically? The idea of inferring contracts from programs is intriguing; it also raises serious epistemological issues. In fact, one may question whether it makes any sense at all. I will leave the question of principle to another post, in … Read more