Re: [PATCH] Supplant the "while case ... break ;; esac" idiom
- From
Johannes Schindelin <johannes.schindelin@gmx.de>
- Date
- Sep 24, 2007, 10:33 UTC
- Message-ID
- <Pine.LNX.4.64.0709241128460.28395@racer.site>
- In-Reply-To
- <20070924080436.GB9112@artemis.corp>
Hi,
On Mon, 24 Sep 2007, Pierre Habouzit wrote:
Show 30 quoted lines
> On Mon, Sep 24, 2007 at 08:01:34AM +0000, Pierre Habouzit wrote:
> > On Mon, Sep 24, 2007 at 07:57:31AM +0000, David Kastrup wrote:
> > > "David Symonds" <dsymonds@gmail.com> writes:
> > >
> > > > On 24/09/2007, David Kastrup <dak@gnu.org> wrote:
> > > >> Mike Hommey <mh@glandium.org> writes:
> > > >>
> > > >> > On Sun, Sep 23, 2007 at 10:42:08PM +0200, David Kastrup wrote:
> > > >> >> -while case $# in 0) break ;; esac
> > > >> >> +while test $# != 0
> > > >> >
> > > >> > Wouldn't -ne be better ?
> > > >>
> > > >> Why?
> > > >
> > > > Because -ne does a numeric comparison, != does a string comparison,
> > > > and it's a numeric comparison happening, semantically speaking.
> > >
> > > I don't see the point in converting $# and 0 into numbers before
> > > comparing them. "!=" is quite more readable, and the old code also
> > > compared the strings.
> >
> > Fwiw $# already is a number. Hence test $# -ne 0 is definitely a
> > better test.
> >
> > $# != 0 would yield sth like (strcmp(sprintf("%d", argc), "0"))
> > $# -ne 0 would yield sth like (argc != atoi("0")).
>
> Of course this holds only for shell where test/[ is a builtin, which
> is the at least the case for zsh, bash, and dash (but not posh).The reason we used "case" is that this has always been a builtin (has to be, because it changes workflow).
Therefore I am somewhat uneasy that the patch went in so easily, especially given a message that flies in the face of our endeavours to make git less dependent on any given shell (as long as it is not broken to begin with).
Ciao, Dscho