Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!wuarchive!wums2!bethge
From: bethge@wums.wustl.edu
Newsgroups: comp.lang.fortran
Subject: Re: Fortran functions
Message-ID: <1452.25c8b994@wums.wustl.edu>
Date: 2 Feb 90 04:35:00 GMT
References: <1990Jan30.191039.12165@siia.mv.com>
Distribution: na
Lines: 33

In article <1990Jan30.191039.12165@siia.mv.com>, wje@siia.mv.com
(Bill Ezell) writes:
> 	character*5 foo
> 	character*5 ans
> 	ans = foo(arg)
> where foo is a function, not in the same file. Foo is not declared external.
> ... how does [the compiler] know that the use of foo is a function call,
> and not a subscript operation?

Simple. If FOO has not previously been declared as an array, then FOO()
cannot be a subscript operation, so it must be a function call.

The "CHARACTER*5 FOO" is *not* an array declaration, because in Fortran
a  character  string  is  *not*  simply  an array of characters, but is
rather a distinct type of object.  (Fortran is IMHO superior to several
other popular languages in this respect.)

This also answers your other question:
> ... is there any difference between:
> 	character*5 var
> 	character var*5
> 	character var(5)

The first two are identical, and are character strings of length 5. The
third  is  an  array  of  characters (actually, of character strings of
length 1), with dimension 5.  It is *not* the same.

If a character string were an array, it could  not  be  returned  as  a
function value, right?

_______________________________________________________________________
Paul H. Bethge                                    bethge@wums.wustl.edu
Washington University, St. Louis                     bethge@wums.bitnet