Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!mailrus!purdue!i.cc.purdue.edu!h.cc.purdue.edu!s.cc.purdue.edu!ags
From: ags@s.cc.purdue.edu (Dave Seaman)
Newsgroups: comp.lang.fortran
Subject: Re: Dubious Fortran Construct
Message-ID: <3684@s.cc.purdue.edu>
Date: 14 Dec 88 22:45:26 GMT
References: <22994@sgi.SGI.COM> <11800009@modcomp>
Reply-To: ags@s.cc.purdue.edu (Dave Seaman)
Organization: Purdue University
Lines: 37

In article <11800009@modcomp> joe@modcomp.UUCP writes:
 [ You all know what the code example looks like by now ]
>Because the CONTINUE statement is being used as the terminating statement of
>two scopes, an ambiguity exists, since GOTO can only branch into a single
                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>scope.  Which scope is selected is not stated by the f77 standard.  
 ^^^^^

A GOTO cannot branch INTO any scope whatsoever.  See paragraph 11.10.8 of
the standard.  The important word here is INTO, meaning "from the outside
to the inside".  A GOTO can branch WITHIN as many scopes as it pleases, but
it cannot enter a scope except through the top.  There is no ambiguity.

>Your
>implied intepretation of "select that scope which makes sense for the GOTO
>in question" is a nice feature that Smart Compilers (like mine (:->)) can
>implement.  

I don't know who you are referring to here.  You quoted my argument that
the construct is illegal, so I take it you are addressing me.  But I have
never attempted to "interpret" that which is not allowed by the standard in
the first place.  I do not object to extensions, as long as it is
understood that that is what they are.

>However, wording to *require* that behavior is not present in
>the standard.  Hence any program that makes use of the ambiguity is
>nonstandard conforming.

You are correct in stating that standard does not require any particular
behavior when confronted by a program that is not standard-conforming.  As
I have explained, there is no ambiguity:  the program most definitely is
not standard-conforming.  The compiler may do absolutely anything it likes
with the program, including refusing to compile it.

Dave Seaman
-- 
Dave Seaman	  					
ags@j.cc.purdue.edu