Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!uakari.primate.wisc.edu!aplcen!boingo.med.jhu.edu!haven!mimsy!oasys!dtoa1!roth
From: roth@dtoa1.dt.navy.mil (Roth)
Newsgroups: comp.lang.fortran
Subject: Re: dynamic storage
Message-ID: <6245@oasys.dt.navy.mil>
Date: 5 Mar 91 19:51:14 GMT
References: <38747@netnews.upenn.edu>
Sender: news@oasys.dt.navy.mil
Reply-To: roth@dtoa1.dt.navy.mil (Pete Roth)
Organization: David Taylor Research Center, Bethesda, MD
Lines: 48

In article <38747@netnews.upenn.edu> lmeyer@eniac.seas.upenn.edu (Basya Meyer) writes:
>As a 'c' programmer who must work in fortran, I need your help!  Is there
>any way in fortran to create something (roughly approximating) a stack or
>linked list?  I would like to allocate spaces in memory as I go along.
>
>Thanks,
>
>Basya

Assuming your compiler is Fortran 77 or earlier:

Part 1: implement your stack as an array, and use an integer
as a pointer into it. Briefly, without error checking, the data looks like
		integer stkptr
		real(?) stack( 100 )
		data stkptr / 0 /
& a push looks like
		subroutine push( areal )
		if ( stkptr .LT. 100 ) then
			stkptr = stkptr + 1
			stack( stkptr ) = areal
		else
			print *, 'stack overflow'
		endif
		end
etc.

Part 2: linked list as two arrays: first array is integer, and holds the
index of the location of the datum in the second array.
		integer lstptr( 100 )
		real(?) list( 100 )

an ordered list will have lstptr(1) = 1, lstptr(2) = 2, etc.

Part 3: Allocate memory as you go along is not fortran unfortunately,
but your system may have an interface that allows you to do that.

Apologies for not having something I can just e-mail you.

Recommended reading: Day, A. Colin, FORTRAN TECHNIQUES, Cambridge University
Press, 32 E 57th St, NYNY, 1979 (latest edition) ISBN 0 521 09719 3 paper
ISBN 0 521 08549 7 hardback

Also: Kernighan & Plauger, SOFTWARE TOOLS, Addison Wesley (I think; it looks
like someone stole my copy...)

Peter N Roth      roth@dtoa1.dt.navy.mil
Objects in this office are closer than they appear.