Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!cs.uoregon.edu!ns.uoregon.edu!milton!seymour
From: seymour@milton.u.washington.edu (Richard Seymour)
Newsgroups: comp.lang.fortran
Subject: Re: pointers in MIPS Fortran?
Message-ID: <1991May16.215418.1021@milton.u.washington.edu>
Date: 16 May 91 21:54:18 GMT
References: <1991May15.162734@IASTATE.EDU> <1991May16.214854.29357@milton.u.washington.edu>
Organization: University of Washington, Seattle
Lines: 26

In article <1991May15.162734@IASTATE.EDU> keinert@IASTATE.EDU (Keinert Fritz) writes:
...about finding an undocumented "pointer(p,real)" declaration in 
>DEC f77 version 2.1 compiler (for MIPS-based DEC 2100), but
>	real x
>	pointer  (p, x)
>makes p a pointer to a real variable. You can do things like   
> p=x   (p is now pointing to x),    
> x=p  (assign to x the value of whatever p is pointing to), and so on.

although not as true-pointer-like as the above quote implies, you have
somewhat similar abilities in many DEC fortrans: both VMS and PDP-11.
In VMS fortran, creative use of the  %LOC(variable) and %VAL(variable)
in code or subroutine calls can produce pointer-like operations.
Something like:     point=%LOC(variable)
                     call foo(%VAL(point))
                     ....
                    subroutine foo(target)
                   x=target

"x" will end up receiving whatever datum was inside "variable"
and if you'd used   call foo(%VAL(point+4))
"x" would get whatever was in the longword FOLLOWING variable...

additonally, you could do   x=%REF(%VAL(point+4)) in the main program
for the same result.
--dick