Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!unmvax!brainerd
From: brainerd@unmvax.unm.edu (Walt Brainerd)
Newsgroups: comp.lang.fortran
Subject: Re: dpANS Fortran 8x
Message-ID: <150@unmvax.unm.edu>
Date: 16 Jun 89 18:06:35 GMT
References: <147@unmvax.unm.edu> <13939@lanl.gov>
Distribution: usa
Organization: University of New Mexico at Albuquerque
Lines: 27

In article <13939@lanl.gov>, jlg@lanl.gov (Jim Giles) writes:
> If you haven't got a complete definition of the semantics of POINTERS,
> 
In my last posting, I quoted verbatim the complete semantics of pointers
quoted directly from the new proposed standard.

> Also, if the new functionality is separable from the old, traditional,
> uses of pointers, why does this new functionality share the same syntax?
> This violates the principle of orthogonality in language design.  Separate
> features should have separate syntax.  So: aliasing array sections should
> be _different_ than implementing recursive data structures!

The _point_ I was trying to make with the example, is that the "new" and "old"
uses are exactly the same and _should_ share the same syntax.

If you think of a pointer as just an ADDRESS
(possibly one that can be incremented and multiplied by 7, etc.),
(this sort of thing certainly has occurred in Fortran implementions)
then the proposed Fortran pointers do not fit with that model.
If you think of a pointer as a POINTER (pointing to, referencing, or aliasing
another object), then all uses of pointers in the proposed Fortran standard
fit within this notion (including "tradidional" uses of pointers
to implement linked lists and other data structures).
In summary, the uses and description of pointers are consistent as proposed;
it may not fit some notions of what people have thought of as pointers.

Walt Brainerd  Unicomp, Inc.  brainerd@unmvax.unm.edu