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From: Bart Schaefer <schaefer@brasslantern.com>
To: Felipe Contreras <felipe.contreras@gmail.com>
Cc: Roman Perepelitsa <roman.perepelitsa@gmail.com>,
	Zsh hackers list <zsh-workers@zsh.org>
Subject: Re: Bug with unset variables
Date: Thu, 12 Nov 2020 11:26:28 -0800	[thread overview]
Message-ID: <CAH+w=7ZwyKq_RxM_RXWu42Y-RbCkRtrLTqesfqCmFNc_C_CwoA@mail.gmail.com> (raw)
In-Reply-To: <CAMP44s09or4ZtTiPW8yz8K+jpVqFKQVZtQnNUfA0zVda5zFH-g@mail.gmail.com>

On Thu, Nov 12, 2020 at 10:47 AM Felipe Contreras
<felipe.contreras@gmail.com> wrote:
>
> No. Zsh is not consistent. I did not type /typeset var=''/, I typed
> /typeset var/.

At the global level you cannot write

VAR

to create a variable named "VAR".

VAR=

both creates a variable and assigns it empty string.

So now we have to decide what to do when with local variables.  They
can either have a totally new semantic, or we can follow the semantic
for globals.  Guess which one makes more sense when you are adding
local scope to a language which previously had only two possible
conceptions of variables (exist and are empty, or do not exist at
all).

That said ...

> Adding a setopt option for the new behavior doesn't break a lot of
> existing zsh code.

It probably wouldn't break any _scripts_ even to modify the behavior
of KSH_TYPESET for this.  Whether we can cleanly perform an implicit
unset in the C code structure, and (if not) whether cobbling this in
is worthwhile, I haven't investigated or formed an opinion.


  parent reply	other threads:[~2020-11-12 19:26 UTC|newest]

Thread overview: 53+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-11 15:57 Felipe Contreras
2020-11-11 16:13 ` Roman Perepelitsa
2020-11-11 16:56   ` Felipe Contreras
2020-11-11 17:02     ` Roman Perepelitsa
2020-11-11 18:03       ` Felipe Contreras
2020-11-11 18:16         ` Roman Perepelitsa
2020-11-11 20:42           ` Felipe Contreras
2020-11-12  0:20             ` Mikael Magnusson
2020-11-12  1:10               ` Felipe Contreras
2020-11-12  8:45             ` Roman Perepelitsa
2020-11-12 10:47               ` Peter Stephenson
2020-11-12 18:48                 ` Bart Schaefer
2020-11-12 19:49                 ` Felipe Contreras
2020-11-12 18:46               ` Felipe Contreras
2020-11-12 19:10                 ` Roman Perepelitsa
2020-11-12 21:08                   ` Felipe Contreras
2020-11-13  8:51                     ` Roman Perepelitsa
2020-11-14  0:52                       ` Felipe Contreras
2020-11-14  5:41                         ` Roman Perepelitsa
2020-11-16 19:41                           ` Felipe Contreras
2020-11-16 20:22                             ` Roman Perepelitsa
2020-11-17 20:28                               ` Felipe Contreras
2020-11-18 22:45                                 ` Daniel Shahaf
2020-11-22  1:20                                   ` Felipe Contreras
2020-11-23  4:00                                     ` Daniel Shahaf
2020-11-23  6:18                                       ` Felipe Contreras
2020-11-19  2:59                                 ` Bart Schaefer
2020-11-22  1:50                                   ` Felipe Contreras
2020-11-17 20:54                             ` Bart Schaefer
2020-11-22  1:49                               ` Felipe Contreras
2020-11-23  6:48                                 ` Bart Schaefer
2020-11-23  7:26                                   ` Felipe Contreras
2020-11-23 20:26                                     ` Bart Schaefer
2020-11-23 23:39                                       ` Felipe Contreras
2020-11-24  0:52                                         ` Bart Schaefer
2020-11-25  8:46                                           ` Felipe Contreras
2020-11-27 15:44                                             ` Daniel Shahaf
2020-11-27 20:49                                               ` Felipe Contreras
2020-11-27 20:59                                                 ` Daniel Shahaf
2020-11-27 21:33                                                   ` Bart Schaefer
2020-11-27 23:37                                                     ` Daniel Shahaf
2020-11-27 23:45                                                       ` Bart Schaefer
2020-11-28  0:24                                                       ` Bart Schaefer
2020-11-28  7:32                                                         ` Bart Schaefer
2020-11-28 12:05                                                         ` Felipe Contreras
2020-11-12 19:26                 ` Bart Schaefer [this message]
2020-11-12 21:48                   ` Felipe Contreras
2020-11-13 22:17                     ` Bart Schaefer
2020-11-14  0:58                       ` Felipe Contreras
2020-11-11 18:36         ` Bart Schaefer
2020-11-11 21:08           ` Felipe Contreras
2020-11-11 17:02     ` Peter Stephenson
2020-11-11 18:05       ` Felipe Contreras

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