From: Felipe Contreras <felipe.contreras@gmail.com>
To: Bart Schaefer <schaefer@brasslantern.com>
Cc: Zsh hackers list <zsh-workers@zsh.org>
Subject: Re: One possible answer to typeset vs. unset
Date: Wed, 23 Dec 2020 17:00:25 -0600 [thread overview]
Message-ID: <CAMP44s2VE9_e+g1Z+ViH_qkCntjDpPjt72PTYP-20nUhsYyUBg@mail.gmail.com> (raw)
In-Reply-To: <CAH+w=7aQeZjFAaJZ+E5DWQG45jvh-VvkT=PAMarpugaL+KcJ4w@mail.gmail.com>
Hello Bart,
Sorry about the delay, I've been busy with other projects.
I merged my approach and your approach and I'll be sending a patch to
show the resulting differences.
On Fri, Dec 4, 2020 at 6:52 PM Bart Schaefer <schaefer@brasslantern.com> wrote:
> On Fri, Dec 4, 2020 at 3:04 AM Felipe Contreras
> <felipe.contreras@gmail.com> wrote:
> >
> > Next, I think all the instances in which PM_UNSET is checked should be
> > verified, to see if PM_DECLAREDNULL makes sense in those. I'll do
> > that.
>
> In cases I've discovered so far, it's actually more likely that one
> has to check whether PM_UNSET and PM_DECLARED are boolean different,
> rather than whether both are (not) set.
Literally the first instance of PM_USET I checked shows a discrepancy
between my approach and your approach.
f () {
local var
print ${(t)var}
}
f
With my approach this prints "scalar-local" (I think correctly). With
your approach it doesn't print anything.
> > And I think that's it. All that's left is deciding what flag would
> > turn this mode on.
>
> I'm leaning toward POSIXBUILTINS.
Would ksh emulation enable this flag?
> > Lastly, I don't know if there is any low-hanging fruit, for example;
> > doing the same as bash 5.0 with localvar_inherit and localvar_unset.
>
> I thoroughly dislike localvar_inherit. I wonder if it's in bash 5.0
> just to be able to compare the suggested semantics from that rejected
> POSIX proposal we've previously discussed. I may be biased by long
> use of the zsh semantic, but treating global -> local like environ ->
> global seems weird, unless there's also a way to "export" a local back
> to global.
After considering it further I don't think it makes sense to have this
as default.
No other language does something like that.
> > I don't quite get localvar_unset, but seems to also be a sensible default.
>
> If I'm reading the bash manual correctly, localvar_unset means that
> "unset foo" behaves like "local foo; unset foo". Thus (Chet will
> probably correct me):
If so I don't think it makes sense to have this as default.
--
Felipe Contreras
next prev parent reply other threads:[~2020-12-23 23:00 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-28 19:49 Bart Schaefer
2020-11-28 20:00 ` Bart Schaefer
2020-11-28 20:21 ` Bart Schaefer
2020-12-01 8:54 ` Felipe Contreras
2020-12-03 21:19 ` Bart Schaefer
2020-12-04 11:04 ` Felipe Contreras
2020-12-04 15:49 ` Bart Schaefer
2020-12-04 19:47 ` Bart Schaefer
2020-12-05 0:22 ` Bart Schaefer
2020-12-05 0:28 ` Bart Schaefer
2020-12-05 0:51 ` Bart Schaefer
2020-12-05 22:17 ` Bart Schaefer
2020-12-23 23:00 ` Felipe Contreras [this message]
2020-12-02 17:18 ` Vincent Lefevre
2020-12-02 18:03 ` Bart Schaefer
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