From owner-sc22wg5+sc22wg5-dom8=www.open-std.org@open-std.org Tue Jun 16 23:13:04 2015 Return-Path: X-Original-To: sc22wg5-dom8 Delivered-To: sc22wg5-dom8@www.open-std.org Received: by www.open-std.org (Postfix, from userid 521) id 09C573586E6; Tue, 16 Jun 2015 23:13:03 +0200 (CEST) Delivered-To: sc22wg5@open-std.org Received: from mail-yh0-f42.google.com (mail-yh0-f42.google.com [209.85.213.42]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (No client certificate requested) by www.open-std.org (Postfix) with ESMTP id 1018B3568C8 for ; Tue, 16 Jun 2015 23:13:03 +0200 (CEST) Received: by yhak3 with SMTP id k3so20496302yha.2 for ; Tue, 16 Jun 2015 14:13:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=a3NYUmcSc2AhFXLE2QmeGezk7XZEC3d8jFBt/8/at7k=; b=cCYZqzgFecIVbHBRfcyxEOEgZm56M1L1PtNfzVJjaYpKsuMogIyG5zJbjdFEdbqMnc 5o/CUjTZYnni6cic57HoPO7tHeZOAvk8WoJcKds8bSKmyRZs2PdF/kSkioDRtD7mqxdK Gub43tHC4M/EpPfE9Ker03yXKp1BmwIGCmqOFcr+hQA1kxxqfCFSC/4rkuAZCU18olzi mFQldwqKf3VTO/aRlK7N2KpcDzDd+iPRkT5tFi0nzlfAdS3u4jpKcJDFnaRLXRWx72M+ N1DnQnyCFvCNIqM0mZ8iywDzOqDgJ+5/X+B1Y6SdKOTxllbQ3v4qZt3iyDkiqVZZ9J0k Kyxw== MIME-Version: 1.0 X-Received: by 10.170.47.197 with SMTP id 188mr2876924ykp.62.1434489181908; Tue, 16 Jun 2015 14:13:01 -0700 (PDT) Received: by 10.13.253.5 with HTTP; Tue, 16 Jun 2015 14:13:01 -0700 (PDT) In-Reply-To: References: Date: Tue, 16 Jun 2015 14:13:01 -0700 Message-ID: Subject: Re: Assignment to ero-sized strings and arrays From: Walt Brainerd To: fortran standards email list for J3 , "sc22wg5@open-std.org" Content-Type: multipart/alternative; boundary=001a1139e6aa1f38c20518a90a0f Sender: owner-sc22wg5@open-std.org Precedence: bulk --001a1139e6aa1f38c20518a90a0f Content-Type: text/plain; charset=UTF-8 OK, I agree with Malcolm that just because there are false statements in the standard, it doesn't mean implementors will follow them. But to make the standard consistent, the following should be added: No value is assigned to the variable if it is of type integer, real, or complex and its value is zero. And for completeness, we need to include the logical type. What is the exceptional value for logical? I guess false is the better candidate. On Tue, May 26, 2015 at 3:27 PM, Walt Brainerd wrote: > I am willing to try this one more time. > > Tell me I am crazy, stupid, or whatever; it has happened before. > > But to ignore this puzzles me. Is anybody going to correct this error? > > 7.2.1.3(1) of the F08 standard says: > > No value is assigned to the variable if it is of type character and zero > length, or is an array of size zero. > > It is still in N2014, if that is the latest. > > Consider the program: > > program f > character(len=:), allocatable :: c > c = "" > print *, len(c), "X"//C//"X" > c = "QQQ" > print *, len(c), "X"//C//"X" > end program f > > The sentence quoted says that the second assignment does not > assign the value QQQ because the length of c is zero. I don't > think that is what is intended. > > Just delete the sentence' it was silly, but wasn't wrong in F95. > > -- > Walt Brainerd > -- Walt Brainerd --001a1139e6aa1f38c20518a90a0f Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
OK, I agree with Malcolm that just because there are false=
statements in the standard, it doesn't mean implementors
will follow them.

But to make the standard consis= tent, the following should be added:

No value is assigned to the variable if i= t is of type integer, real, or
complex and its value is zero.

And for completeness, we need to include = the logical type.
What is the exceptional value for logical? I guess false is
the better candidate.

= On Tue, May 26, 2015 at 3:27 PM, Walt Brainerd <walt.brainerd@gmail.= com> wrote:
I am willing to try this one more time.

Tell me I am c= razy, stupid, or whatever; it has happened before.

But t= o ignore this puzzles me. Is anybody going to correct this error?

7.2.1.3(1) of = the F08 standard says:
No value is assign= ed to the variable if it is of type character and zero
length, or= is an array of size zero.

It is still in N2014, i= f that is the latest.

Consider the program:
<= div>
program f
character(len=3D:), allocata= ble :: c
c =3D ""= ;
print *, len(c), "X= "//C//"X"
c= =3D "QQQ"
print= *, len(c), "X"//C//"X"
end program f

The sente= nce quoted says that the second assignment does not
assign the value QQQ because the length of c is z= ero. I don't
think tha= t is what is intended.
Just delete the sentence= ' it was silly, but wasn't wrong in F95.

--
Walt Brain= erd



--
Walt Brainerd
--001a1139e6aa1f38c20518a90a0f--