Short works

Books : reviews

Bertrand Meyer.
Object-oriented Software Construction.
Prentice Hall. 1988

rating : 2 : great stuff

An excellent introduction to OO software design from a formalist viewpoint, based around, but not dependent on, the Eiffel language.

Bertrand Meyer.
Introduction to the Theory of Programming Languages.
Prentice Hall. 1990

rating : 2.5 : great stuff

Denotational and axiomatic semantics for the masses.

Jean Bezivin, Bertrand Meyer, Jean-Marc Nerson.
Technology of Object-Oriented Languages and Systems: proceedings of TOOLS 2, Paris, 1990.
Angkor. 1990

Bertrand Meyer.
Eiffel: the Language.
Prentice Hall. 1992

rating : 3 : worth reading

The book of the language, from its inventor, written in his usual discursive style. A good read for understanding the language, rather harder, but still possible, to use as a laguange reference.

Bertrand Meyer.
Object-oriented Software Construction: 2nd edn.
Prentice Hall. 1997

A complete reworking of the first edition, and extended to cover new areas. Some think this long-awaited second edition is not an improvement on its slimmer original. I haven't read it yet.

Bertrand Meyer.
Agile!: the good, the hype and the ugly.
Springer. 2014

rating : 2.5 : great stuff
review : 8 January 2015

Are you attracted by the promises of agile methods but put off by the fanaticism of many agile texts? Would you like to know which agile techniques work, which ones do not matter much, and which ones will harm your projects? Then you need Agile!: the first exhaustive, objective review of agile principles, techniques and tools.

Agile methods are one of the most important developments in software over the past decades, but also a surprising mix of the best and the worst. Until now every project and developer had to sort out the good ideas from the bad by themselves. This book spares you the pain. It offers both a thorough descriptive presentation of agile techniques and a perceptive analysis of their benefits and limitations.

I’ve been a fan of aspects of Agile Programming ever since I first read about it. In particular the incremental style works very well in building software to support scientific research, where you really don’t know what you need to do next until you have run the prior experiments and come up with the next hypotheses; the discipline of YAGNI (“You ain’t gonna need it”) can save a lot of time and effort here. The “always have a working system” (continuous integration) part also works well for student projects, with their rigidly time-boxed hand-in dates. However, I also have a background in formal methods, so some of the more seemingly heretical and potentially “hacky” bits of the process do raise an eyebrow.

That’s where Agile! comes in. Bertrand Meyer is in the “strong software engineering” camp, strong on specification and design, and the inventor of “design by contract” in the 1980s, an approach of which I’m also a fan. What is he going to say about this new approach?

Unsurprisingly, he thinks some of it is bad; very bad. More surprisingly, possibly, he thinks some of it is not just good, but even “brilliant” (his term). He goes through the various components of the various Agile approaches, describing and critiquing them. He puts most emphasis on Scrum, with which he is most familiar (even being a certified Scrum Master), but also covers Crystal, XP, and Lean.

In summary, the ugly includes the lack of upfront specification and design (even allowing for the fact it will change later) and specifically user stories as the basis for requirements and test-driven development as the basis for design; the hype includes pair programming and collective code ownership the good includes refactoring; the brilliant includes iterative development, continuous integration, and test first development (associating a test with every piece of functionality).

His argument for up-front specification and design includes the need for finding good abstractions, which will not automatically emerge from a test-code-refactor cycle. A specification is more abstract than a test suite, because it covers all the cases (thereby removing the problem of induction, or inducing the general from the specific). Similarly, he argues that user stories are to requirements what test cases are to specifications, including the same problems of lack of generality and completeness. We presumably need another aphorism to complement Dijsktra’s famous observation that testing can show the presence of bugs, but never their absence. Maybe it should be something like user stories can show the inclusion of functionality, but never its omission.

My only peeve about the book is some of the typography. Occasional paragraphs that are “asides” are set in a smaller font size. Every time, I initially parsed these as quotations, and had to backtrack. Notwithstanding this minor point, Agile! is an excellent thoughtful critique of Agile methods. Although Meyer introduces and describes all the concepts he critiques, I don’t think it is a stand-alone text, as those descriptions are somewhat brief. However, is should be required reading for anyone using, or about to use, an Agile approach.

At 170pp, it is a fast, if dense, read. I laughed out loud on several occasions. For example, he comments on the picture accompanying the agile manifeso:

p1. The sight of a half-dozen middle-aged, jeans-clad, potbellied gentlemen turning their generous behinds to us appears to have provided the decisive sex appeal. Personally, had I wanted to convey the suggestion of agility, I might have turned to something like the cover photograph of this book — which only demonstrates how out of tune I am with the times, since the above picture was successful beyond anyone’s dreams.

Papers/Articles : reviews

Bertrand Meyer. On Formalism in Specification. IEEE Software, 6-26. Jan. 1985

Introduces The Seven Sins of the Specifier