Path: utzoo!attcan!uunet!convex!convex1.convex.com!rosenkra
From: rosenkra@convex1.convex.com (William Rosencranz)
Newsgroups: comp.lang.fortran
Subject: Re: another side effect question
Keywords: function, print
Message-ID: <104561@convex.convex.com>
Date: 2 Aug 90 07:45:48 GMT
References: <968@nikhefh.nikhef.nl>
Sender: usenet@convex.com
Organization: Convex Computer Corporation; Richardson, TX
Lines: 54

In article <968@nikhefh.nikhef.nl> t19@nikhefh.nikhef.nl (Geert J v Oldenborgh) writes:
>
>While on the subject of side effect of functions, is there anything in the 
>(77) standard which prohibits
>
>      PRINT *,AAP(1.)
>      END
>      REAL FUNCTION AAP(X)
>      PRINT *,'THIS IS AAP'
>      AAP = X
>      END
>
>
>None of the Fortrans I use properly prints this.  Yet, I find it a useful 
>construct to remind me which set of functions I am using (of course only 
>printing on the first call).
>
>Geert Jan van Oldenborgh
>oldenborgh@nikhef.nl

you can't do i/o during a print statement, i believe, since this is recursive
which fortran does not like too much.

note that you CAN do this in C:

	double app();

	main ()
	{
		printf ("%6.4f\n", app(1.));
	}

	double app(arg)
	double arg;
	{
		printf ("THIS IS AAP\n");
		return (arg);
	}

it would result in:

	THIS IS AAP
	1.0000

C has no problems at all with recursion, in general, another reason it
should not be dismissed...

-bill
rosenkra%c1yankee@convex.com

(my opinions, not my employer's...)

Bill Rosenkranz            |UUCP: {uunet,texsun}!convex!c1yankee!rosenkra
Convex Computer Corp.      |ARPA: rosenkra%c1yankee@convex.com