From: Junio C Hamano <gitster@pobox.com>
To: Felipe Contreras <felipe.contreras@gmail.com>
Cc: git@vger.kernel.org
Subject: Re: [PATCH 1/3] completion: be nicer with zsh
Date: Sun, 29 Jan 2012 21:50:44 -0800 [thread overview]
Message-ID: <7v4nvdeo23.fsf@alter.siamese.dyndns.org> (raw)
In-Reply-To: <7v8vkperli.fsf@alter.siamese.dyndns.org> (Junio C. Hamano's message of "Sun, 29 Jan 2012 20:34:17 -0800")
Junio C Hamano <gitster@pobox.com> writes:
> Avoiding zsh's bug that cannot use conditional assignment on the no-op
> colon command (if the bug is really that; it is somewhat hard to imagine
> if the bug exists only for colon command, though) *is* by itself a good
> justification for this change, even though the resulting code is harder to
> read for people who are used to read shell scripts.
Just from my curiosity, I am wondering what zsh does when given these:
bar () { echo "frotz nitfol xyzzy" }
unset foo; : ${foo:=$(bar)}; echo "<$?,$foo>"
unset foo; true ${foo:=$(bar)}; echo "<$?,$foo>"
unset foo; echo >/dev/null ${foo:=$(bar)}; echo "<$?,$foo>"
The first one is exactly your "And yet another bug in zsh[1] causes a
mismatch; zsh seems to have problem emulating wordspliting, but only when
the ':' command is involved.", so we already know it "seems to have
problem emulating word-splitting" (by the way, can we replace that with
exact description of faulty symptom? e.g. "does not split words at $IFS"
might be what you meant but still when we are assigning the result to a
single variable, it is unclear how that matters).
Note that I am not suggesting to rewrite the existing ": ${var:=val}" with
"echo ${var:val} >/dev/null" at all. Even if "echo >/dev/null" makes it
work as expected, your rewrite to protect it with an explicit conditional
e.g. "test -n ${foo:-} || foo=$(bar)" would be a lot better than funny
construct like "echo >/dev/null ${foo:=$(bar)", because it is not an
established shell idiom to use default assignment with anything but ":".
Thanks.
next prev parent reply other threads:[~2012-01-30 5:50 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-29 23:41 [PATCH 0/3] completion: trivial cleanups Felipe Contreras
2012-01-29 23:41 ` [PATCH 1/3] completion: be nicer with zsh Felipe Contreras
2012-01-30 4:34 ` Junio C Hamano
2012-01-30 5:50 ` Junio C Hamano [this message]
2012-01-30 10:30 ` Felipe Contreras
2012-01-30 10:35 ` Felipe Contreras
2012-01-30 18:07 ` Junio C Hamano
2012-01-30 18:21 ` Felipe Contreras
2012-01-29 23:41 ` [PATCH 2/3] completion: remove old code Felipe Contreras
2012-01-30 2:36 ` Jonathan Nieder
2012-01-30 3:24 ` Felipe Contreras
2012-01-30 3:27 ` Jonathan Nieder
2012-01-30 4:27 ` Junio C Hamano
2012-01-30 10:51 ` Felipe Contreras
2012-01-30 11:19 ` Frans Klaver
2012-01-30 11:55 ` Felipe Contreras
2012-01-30 12:21 ` Frans Klaver
2012-01-30 13:59 ` Felipe Contreras
2012-01-30 14:02 ` Jonathan Nieder
2012-01-29 23:41 ` [PATCH 3/3] completion: remove unused code Felipe Contreras
2012-01-30 2:50 ` Jonathan Nieder
2012-01-30 3:29 ` Jonathan Nieder
2012-01-30 3:30 ` Felipe Contreras
2012-01-30 7:44 ` Thomas Rast
2012-01-30 8:22 ` Junio C Hamano
2012-01-30 10:38 ` Felipe Contreras
2012-01-30 13:19 ` Thomas Rast
2012-01-30 13:51 ` Felipe Contreras
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: http://vger.kernel.org/majordomo-info.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=7v4nvdeo23.fsf@alter.siamese.dyndns.org \
--to=gitster@pobox.com \
--cc=felipe.contreras@gmail.com \
--cc=git@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://80x24.org/mirrors/git.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).