lmeyer@eniac.seas.upenn.edu (Basya Meyer) (03/06/91)
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
roth@dtoa1.dt.navy.mil (Roth) (03/06/91)
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.
session@uncw.UUCP (Zack C. Sessions) (03/07/91)
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 There is no true dynamic memory allocation possible with standard FORTRAN. As another follow-up poster has shown, implementation of stacks, linked lists (as well as queues, etc.) is nothing more than an exercise in Data Structures. What some do (if both a C AND a FORTRAN compiler is available) is use C subroutines to perform the dynamic allocation. Zack Sessions session@uncw.UUCP
khb@chiba.Eng.Sun.COM (Keith Bierman fpgroup) (03/07/91)
In article <1050@uncw.UUCP> session@uncw.UUCP (Zack C. Sessions) writes:
an exercise in Data Structures. What some do (if both a C AND a FORTRAN
compiler is available) is use C subroutines to perform the dynamic
C is irrelvant. It is really an OS service issue. On many systems
(VAX, Sun, CDC, etc.) you can do it in extended Fortran. You may
prefer BLISS, Cybil, assembler or old Norse .....
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Keith H. Bierman kbierman@Eng.Sun.COM | khb@chiba.Eng.Sun.COM
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Mountain View, CA 94043session@uncw.UUCP (Zack C. Sessions) (03/07/91)
khb@chiba.Eng.Sun.COM (Keith Bierman fpgroup) writes: >In article <1050@uncw.UUCP> session@uncw.UUCP (Zack C. Sessions) writes: > an exercise in Data Structures. What some do (if both a C AND a FORTRAN > compiler is available) is use C subroutines to perform the dynamic >C is irrelvant. It is really an OS service issue. On many systems >(VAX, Sun, CDC, etc.) you can do it in extended Fortran. You may >prefer BLISS, Cybil, assembler or old Norse ..... >Keith H. Bierman kbierman@Eng.Sun.COM | khb@chiba.Eng.Sun.COM I did not imply that C was _required_ to do dynamic memory allocation. Certainly other languages do as well, most notably PL/1 with it's ALLOCATE statement. I was merely pointing out an alternative since dynamic memory allocation is NOT part of standard FORTRAN, but MAY be available with some implementations of *Extended* FORTRAN. Oh, and since I *did* suggest C, it may be obvious that I would prefer C. Zack Sessions session@uncw.UUCP
lmeyer@eniac.seas.upenn.edu (Basya Meyer) (03/07/91)
In article <KHB.91Mar6151242@chiba.Eng.Sun.COM> khb@chiba.Eng.Sun.COM (Keith Bierman fpgroup) writes: >(VAX, Sun, CDC, etc.) you can do it in extended Fortran. You may >prefer BLISS, Cybil, assembler or old Norse ..... Thank you to all who replied--you have been very helpful and informative. I think I'll try the old Norse.... Basya