Path: utzoo!attcan!uunet!lll-winken!csd4.milw.wisc.edu!uxc!uxc.cso.uiuc.edu!uxd.cso.uiuc.edu!uxe.cso.uiuc.edu!hirchert
From: hirchert@uxe.cso.uiuc.edu
Newsgroups: comp.lang.fortran
Subject: Re: DO loops, anyone? - Apologies!
Message-ID: <50500108@uxe.cso.uiuc.edu>
Date: 17 Mar 89 20:59:00 GMT
References: <459@orange19.qtp.ufl.edu>
Lines: 23
Nf-ID: #R:orange19.qtp.ufl.edu:459:uxe.cso.uiuc.edu:50500108:000:1138
Nf-From: uxe.cso.uiuc.edu!hirchert    Mar 17 14:59:00 1989


Rostyslaw Jarema Lewyckyj (urjlew@ecsvax.UUCP) writes:

>The problem is that the standard allows a code construction that
>easily leads to misuse and stepping over the legal limits. I.e.
>the standard permits a DO loop to end with non trivial executable
>statements (eg  k=k+1 rather than continue or enddo) and it allows
>the closure of multiple DO loops on one statement. 
>...
>I think that the rational solution is to amend the standard (put it
>in 8x or 9x if 8x never makes it) to require DO loops to be terminated
>one at a time with CONTINUE or ENDDO statements.

Fortran 8x has been designed on the assumption that it must be upwards
compatible from FORTRAN 77, but that features can be changed in the next
revision if we warn them about the change in this this revision.  The
warning is declare a feature to be obsolescent.  Both of the practices
you mention have been declared obsolescent.  This means that a Fortran 8x
processor will have to be able to warn you about these practices and that
future processors may make them errors.

Kurt W. Hirchert     hirchert@ncsa.uiuc.edu
National Center for Supercomputing Applications