Subjunctives in Fortran

Humor
1

Any language worth its salt has subjunctives. Consider the (now obsolete and non-standard) DEFNE FILE statement. It goes:

  DEFINE FILE LUN (NREC,RECL,U,N)

The U is a mandatory keyword ( :grinning: ). It probably once meant unformatted.
Now this doesn’t open a file. What it means is “If you were to access a file on this LUN, this is what it would look like”.

Are there other subjunctives? Perhaps the WHENEVER statement in Pro-Fortran or the ON statement in HP-UX.

2

If only it were that easy to make Fortran read and write stream I/O from stdin and stdout. That would be a PERFECT subjunctive.

Do I want a core dump or traceback? Can I process a signal? Do I want a verbose or debug mode? Should I exit on error or using an undefined or NaN value? They lurk everywhere.

3

Think of an optional compiler switch and you probably have one.