From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <zsh-workers-return-17311-mason-zsh=primenet.com.au@sunsite.dk>
Received: (qmail 7009 invoked from network); 10 Jun 2002 17:53:39 -0000
Received: from sunsite.dk (130.225.247.90)
  by ns1.primenet.com.au with SMTP; 10 Jun 2002 17:53:39 -0000
Received: (qmail 17171 invoked by alias); 10 Jun 2002 17:53:03 -0000
Mailing-List: contact zsh-workers-help@sunsite.dk; run by ezmlm
Precedence: bulk
X-No-Archive: yes
X-Seq: 17311
Received: (qmail 17151 invoked from network); 10 Jun 2002 17:52:59 -0000
Date: Mon, 10 Jun 2002 13:52:56 -0400
From: Steve Simmons <scs@ans.net>
To: zsh-workers@sunsite.dk
Subject: Possible zsh bug with unique tied vars in 4.0.4?
Message-ID: <20020610175255.GA10947@ans.net>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.3.27i

The following sequence of commands shows unexpected performance in
zsh when using tied variables and unique processing.  In brief, if
you have tied variables FOO and foo and typeset one of them to unique
(-U), you can use the other to assign non-unique values to the first.
This is counter-intuitive at best :-), and I can see no use for this
feature.  The manual page leads one strongly to believe that a single
variable is created which simply has two names and two presentations;
the experiment below shows that clearly there are other differences
as well.

In most cases this wouldn't matter as I would declare such variables
with

   $ typeset -Tx -U FOO foo

However, when applying -U to useful special vars like PATH you cannot
redeclare the overall type, nor can you simply do

   $ typeset -U PATH

as that leads to the anomalous performance as shown below.  One must
set uniqueness on both forms;

   $ typeset -U PATH
   $ typeset -U path

otherwise $PATH and $path start getting out of sync.

This lack of tieing of secondary variable characteristics may apply
to other items as well (justification, etc); I've not experimented.

I'm running zsh version 4.0.4 on FreeBDS 4.6 RC2.

Steve


superior$ typeset -Tx FOO foo
superior$ echo $FOO

superior$ echo $foo

superior$ FOO="a:b" 
superior$ echo $FOO
a:b
superior$ echo $foo
a b
superior$ foo=($foo a c)
superior$ echo $foo
a b a c
superior$ echo $FOO
a:b:a:c
superior$ typeset -U foo
superior$ echo $foo
a b c
superior$ echo $FOO
a:b:c
superior$ FOO="a:c:$FOO"
superior$ echo $FOO
a:c:a:b:c
superior$ echo $foo
a c a b c
superior$ foo=($foo)
superior$ echo $foo
a c b
superior$ echo $FOO
a:c:b
superior$ echo $ZSH_VERSION
4.0.4
superior$ uname -a
FreeBSD superior.inland-sea.com 4.6-RC FreeBSD 4.6-RC #8: Fri Jun  7 21:27:23 EDT 2002 root@superior.inland-sea.com:/usr/src/sys/compile/SUPERIOR  i386