Posts tagged ‘Void safety’

A safe and stable solution

Reading about the latest hullabaloo around Android’s usage of Java, and more generally following the incessant flow of news about X suing Y in the software industry (with many combinations of X and Y) over Java and other object-oriented technologies, someone with an Eiffel perspective can only smile. Throughout its history, suggestions to use Eiffel have often been met initially — along with “Will Eiffel still be around next year?”, becoming truly riotous after 25 years — with objections of proprietariness, apparently because Eiffel initially came from a startup company. In contrast, many other approaches, from C++ to Smalltalk and Java, somehow managed to get favorable vibes from the media; the respective institutions, from AT&T to Xerox and Sun, must be disinterested benefactors of humanity.

Now many who believed this are experiencing a next-morning surprise, discovering under daylight that the person next to whom they wake up is covered with patents and lawsuits.

For their part, people who adopted Eiffel over the years and went on to develop project after project  do not have to stay awake worrying about legal issues and the effects of corporate takeovers; they can instead devote their time to building the best software possible with adequate methods, notations and tools.

This is a good time to recall the regulatory situation of Eiffel. First, the Eiffel Software implementation (EiffelStudio): the product can be used through either an open-source and a proprietary licenses. With both licenses the software is exactly the same; what differs is the status of the code users generate: with the open-source license, they are requested to make their own programs open-source; to keep their code proprietary, they need the commercial license. This is a fair and symmetric requirement. It is made even more attractive by the absence of any run-time fees or royalties of the kind typically charged by database vendors.

The open-source availability of the entire environment, over 2.5 millions line of (mostly Eiffel) code, has spurred the development of countless community contributions, with many more in progress.

Now for the general picture on the language, separate from any particular implementation. Java’s evolution has always been tightly controlled by Sun and now its successor Oracle. There may actually be technical arguments in favor of the designers retaining a strong say in the evolution of a language, but they no longer seem to apply any more now that most of the Java creators have left the company. Contrast this with Eiffel, which is entirely under the control of an international standards committee at ECMA International, the oldest and arguably the most prestigious international standards body for information technology. The standard is freely available online from the ECMA site [1]. It is also an ISO standard [2].

The standardization process is the usual ECMA setup, enabling any interested party to participate. This is not just a statement of principle but the reality, to which I can personally testify since, in spite of being the language’s original designer and author of the reference book, I lost countless battles in the discussions that led to the current standard and continue in preparation of the next version. While I was not always pleased on the moment, the committee’s collegial approach has led to a much more solid result than any single person could have achieved.

The work of ECMA TC49-TG4 (the Eiffel standard committee) has disproved the conventional view that committees can only design camels. In fact TC49-TG4 has constantly worked to keep the language simple and manageable, not hesitating to remove features deemed obsolete or problematic, while extending the range of the language and increasing the Eiffel programmer’s power of expression. As a result, Eiffel today is an immensely better language than when we started our work in 2002. Without a strong community-based process we would never, for example, have made Eiffel the first widespread language to guarantee void-safety (the compile-time removal of null-pointer-dereferencing errors), a breakthrough for software reliability.

Open, fair, free from lawsuits and commercial fights, supported by an enthusiastic community: for projects that need a modern quality-focused software framework, Eiffel is a safe and stable solution.


[1] ECMA International: Standard ECMA-367: Eiffel: Analysis, Design and Programming Language, 2nd edition (June 2006), available here (free download).

[2] International Organization for Standardization: ISO/IEC 25436:2006: Information technology — Eiffel: Analysis, Design and Programming Language, available here (for a fee; same text as [1], different formatting).

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

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: in

         x.f (...)

the value of x is a reference, which normally denotes an object but could at any time be void (or “null”). If this happens, the resulting “void call” will cause an exception and, usually, a crash.  No amount of testing can remove the risk entirely; the only satisfactory solution is a static one, enforcing void safety at the language level.

To this end, Eiffelists of various nationalities have assembled in the Cloud and sketched the following manifesto, to be published in the English language:

        Avoid a Void: The Eradication of Null Dereferencing
        Bertrand Meyer, Alexander Kogtenkov, Emmanuel Stapf
        White paper available here.
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