Re: FFTW and Fortran.
From: William Clodius (wclodius_at_lanl.gov)
Date: 16 Jun 2004 16:03:26 -0700
Richard Maine <firstname.lastname@example.org> wrote in message news:<email@example.com>...
> Kamaraju Kusumanchi <firstname.lastname@example.org> writes:
> > (1) in, out are already reserved words in fortran 90...
> I suspect that you know this, and just omitted the explanation of
> what you meant, but in case you didn't know.... and even if you
> did know, to make sure that other readers aren't mislead...
> No, there are no reserved words in Fortran. (See footnote 1).
> All Fortran keywords, specifically including "in" and "out"
> may also be used for variable names and other purposes. You
> might make a style choice to avoid using them, but that is a
> personal style choice rather than a requirement of the standard.
> I don't personally think that variables named "in" and "out" are
> likely to be confused with intent(in) and intent(out), so I freely
> use them, but that's a personal judgement.
> Footnote 1. There is one exception in a limited context. Anyway this
> is the only one I can think of. The intrinsic type names (integer,
> real, logical, character, complex, and doubleprecision) may not be
> used as derived type names, so they are reserved in that context.
> They may be used for other things such as variable names (though I'd
> recommend against it) - just not for derived type names.
Footnote 2. I believe END in some limited contexts (perhaps only in
fixed form) behaves as a reserved word to simplify the parsing and
lexical analysis of Fortran programs. You really have to work hard at
doing something obviously dumb to encounter this, but I believe that
(note END starts in column seven and 2 is in column 6) in
& = DUMB
the processor is allowed to treat the END as indicating the end of the
program unit, and not a variable to be assigned the value of DUMB.