Eiffel

Another DOSE of distributed software development

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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




Verification As a Matter Of Course

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At the ACM Symposium on Applied Computing (SAC) in Sierre last week, I gave a talk entitled “How you will be programming in 10 years”, describing a number of efforts by various people, with a special emphasis on our work at both ETH and Eiffel Software, which I think point to the future of software … Read more




A couple of loop examples

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(This entry originated as a post on the EiffelStudio user group mailing list.)  Here are a couple of actual examples of the new loop variants discussed in the blog entry immediately preceding this one. They came out of my current work; I started updating a program to take advantage of the new facility. As a typical example, … Read more




More expressive loops for Eiffel

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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




The theory and calculus of aliasing

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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.







Just another day at the office

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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

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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




Void safety: Getting rid of the spectre of null-pointer dereferencing

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A spectre is haunting programming — the spectre of null-pointer dereferencing. All the programming languages of old Europe and the New World have entered into a holy alliance to make everyone’s programs brittle:  Java, C, Pascal, C++, C# and yes, until recently, Eiffel. The culprit is the use of references to denote objects used in calls: … Read more