In the beginning, there was only one source form for FORTRAN (as it was then known) programs. Each statement was exactly 72 characters long – no more, no less. (See note below.) Columns 1-5 were for statement labels, whole line comments were indicated with a C in column 1, and column 6 was reserved for a continuation indicator. Blanks in the statement field, outside of quoted literals, were ignored. The standard didn’t (and still doesn’t) talk about how source programs are fed into a compiler, but on systems where there were “file types”, the types .for, .f and .ftn were usually recognized as being Fortran.
MoreDoctor Fortran in “I Can C Clearly Now, Part I”
Spend any time in the comp.lang.fortran newsgroup, or other places where programming languages are discussed, and you’ll soon see a new “Which is better, Fortran or C?” thread show up. These never fail to produce heated comments from people who should know better. My answer is that neither is “better” – each has its strengths and weaknesses.
MoreDoctor Fortran Gets Explicit – Again!
Nearly 11 years ago (!) I wrote an item for the Visual Fortran Newsletter on explicit interfaces in Fortran. In recent weeks, I have had to refer quite a few customers to this article, suggesting that many Fortran programmers don’t understand the role and rules of explicit interfaces. However, when I reread the item, I realized that things had changed a bit since Fortran 95, so I figured it was time to revisit the issue.
MoreDoctor Fortran in “Lest Old Acquaintance Be Forgot”
In some of my earlier posts I’ve discussed new features in the Fortran language that might be unfamiliar to some. But this time I’m going to go the other way and describe some really old language features – so old that many newer Fortran programmers are mystified when they see them – but these features are still supported by many current compilers, including Intel Fortran. So let’s set the Wayback Machine to the 1960s and have a look around.
MoreThe Real Doctors of Fortran
In this blog, I refer to myself as “Doctor Fortran”. It’s a joke that started more than ten years ago when I decided to write an “advice column” for what was then the Digital Visual Fortran Newsletter. Everyone liked it so much I stuck with it, but I’ve always been aware of the people who deserve that title far more than I – the members of the Fortran standards committee. As it happens, I am an “alternate” member of the committee representing Intel, but most of the time we are represented by Stan Whitlock. Intel Fortran developer Lorri Menard is our other alternate member. I’ve now attended three standards meetings and thought I’d write up my experience of the most recent and give readers a feel for how the Fortran language’s evolution is guided and its cohesiveness maintained.
MoreThirty Years of Zonker Kookies
It is a beautiful autumn day here in Southern New Hampshire. The air is clear and crisp, the sun is bright and the trees have (finally!) brought out some color, which I can see looking out the window near my cube. But soon, I will pack up the rest of my things and leave that view, and the cube, forever.
MoreDoctor Fortran in “Think, Thank, Thunk”
One of the various responsibilities I have is for the compiler samples (both Fortran and C++). For Intel Visual Fortran, we have a lot of samples – for the other compilers, fewer. The Windows Fortran samples are a mixed lot; some came to us from Microsoft Fortran Powerstation (with or without extensive modification) and some were developed by us (mostly, yours truly.)
MoreDoctor Fortran in “I’ve Come Here For An Argument, Side 2”
My earlier post, “I’ve Come Here For An Argument”, was very popular with my fellow support engineers, as it provided a convenient answer to questions they frequently receive. (For me too, which in part is why I wrote it!) But some people (cough, Ron, cough) are never satisfied, and I’ve been asked to write a follow-up on what else can go wrong when you don’t understand all of Fortran’s argument-passing rules. So, here we go…
MoreDoctor Fortran in “Revert! Revert! The End (of the format) is Nigh!”
Recently, a customer wrote that he wanted to write out the values of an array, all in one line, where the number of elements was not known at compile time. His first attempt at this was:
MoreDoctor Fortran in “I’ve Come Here For An Argument”
One of the most fundamental aspects of Fortran programming is passing arguments to procedures. It is also one of the most misunderstood aspects. In this space today I’ll try to make things clearer.
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