A Farewell to Jean

If you asked me what my favorite programming language is, you might be surprised when I don't say Fortran. No, my favorite is Ada, the language named for the first computer programmer and the result of an international competition sponsored by the US Department of Defense. Jean Ichbiah, the creator of the "Green" language which became Ada, died January 26 at the age of 66.

I met Jean, briefly, back in 1984 when I was working on DEC's VAX Ada compiler project. In March of 1984 I had the delightful task of traveling to Versilles, France, to deliver to Ichbiah's company Alsys a magtape containing the first beta test version of VAX Ada. I spent a week with the Alsys team helping them shake out the compiler, which went on to be one of the most highly regarded implementations of the language. My main assignment from 1983 through 1988 was project leader for VAXELN Ada, a variant which ran on VAX systems under the real-time and embedded OS VAXELN, created by Dave Cutler just before he left DEC for Microsoft. In August 1988 I then joined the VAX Fortran compiler team.

Ada was an elegant and full-featured language with extremely expressive declaration features, multitasking, exception handling, a module facility with intelligent separate compilation and much more. The language gave the programmer the ability to tell the compiler what was allowed and not allowed to happen in the program and this enabled the compiler to do checking at a level rarely seen in other languages. I liked to say that if you could get an Ada program to compile, it would probably run correctly the first time. This, of course, was one of the things that the DoD wanted.

The DoD mandate that Ada must be used in defense contracts was both a blessing and a curse for Ada. A blessing in that it jumpstarted the widespread use of the language, but a curse in that many developers were dragged kicking and screaming into the world of Ada and non-defense programmers often avoided Ada specifically because of the DoD connection. After ten years, the screaming became loud enough that the DoD dropped the Ada mandate, and Ada use pretty much dropped out of sight. The orignal Ada 83 language was updated to Ada 88 and again in 1995, but DEC and most other vendors did not update their implementations.

What's the relevance of Ada to Fortran? Some of the major Fortran 90 features, such as modules and generics, are derived at least in part from Ada. Fortran's separate compilation model made it difficult to implement one of Ada's most elegant module features, IS SEPARATE, which permitted the implementation of a module procedure to be compiled separately from its declaration. The "submodules" proposal for Fortran 2008 finally brings that to the language.

So what's my second favorite language? SNOBOL.
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anonymous's picture

I think it was in 1982 that Keating asked me if we were interested in building an Ada compiler for the VAX, to which I said yes, provided we could use our own intermediate representation which was used by PL/I instead of Diana, and that understandably didn't happen.

anonymous's picture

Ada is alive and well: the language standard got a minor update in 2001, and a major update that was coincidentally published by ISO/IEC last week.

While it is true that a number of vendors did not update their compilers for the 1995 standard, many did. Today we have a number of vendors providing Ada compilers: AdaCore (a GPLed compiler in the GCC family), Aonix, Green Hills, Rational (now part of IBM), DDC-I, RR Software, SofCheck, and others that I've forgotten. And there is an active user community, especially in Europe.

Indeed, I've spent virtually all of my professional life working with Ada in one form or another (27 years, gulp).

Clay B.'s picture

There's a twin blast from the past. I haven't seriously thought of Ada since the ACM SIGADA conference in 1986(?) in Seattle, and SNOBOL has been a compressed spheroid of ice crystals since my Programming Languages class in 1984.

I like LOGO as a programming language, myself.

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