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From: Peter Stephenson <p.w.stephenson@ntlworld.com>
To: zsh-users@zsh.org
Subject: Re: How to impose a numeric sort on negative numbers?
Date: Fri, 03 Jul 2020 21:08:38 +0100	[thread overview]
Message-ID: <3f4d22d506fc069965c1e37d0f06ee585a5073dc.camel@ntlworld.com> (raw)
In-Reply-To: <CAH+w=7Y31mfOrFyYUnAZwR5Bx1vOmTUJFVmKi6qhr1uEP1u=4w@mail.gmail.com>

On Thu, 2020-07-02 at 08:46 -0700, Bart Schaefer wrote:
> Peter Stephenson wrote on Wed, 01 Jul 2020 20:42 +0100:
> > > +++ b/Doc/Zsh/expn.yo
> > > @@ -1097,6 +1097,11 @@ are sorted before those with fewer or none.  Hence the array `tt(foo1 foo02
> > >  foo2 foo3 foo20 foo23)' is sorted into the order shown.
> > >  May be combined with `tt(i)' or `tt(O)'.
> > >  )
> > > +item(tt(DASH()))(
> > > +As tt(n), but a leading minus sign indicates a negative decimal
> > > +integer.  A solo `tt(DASH())' not followed by an integer does
> > > +not trigger numeric sorting.
> > > +)
> 
> It might be possible to change this.  For numeric sort, the function
> eltpcmp() in sort.c ignores everything other than digits that compares
> the same in any pair of the strings.  It could recognize a leading
> hyphen as special.

(I've committed it with DASH() turned into -.)

The doc was just to record the fact that I didn't treat a "-" as "-0",
just as a character "-".  That was a deliberate choice --- I'm
assuming the usual case of a numeric sort will have at least one
decimal digit in the part to be sorted and anything else is
just a hyphen (and definitely not a dash).

pws



  reply	other threads:[~2020-07-03 20:09 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-01 17:45 Sebastian Gniazdowski
2020-07-01 18:02 ` Mikael Magnusson
2020-07-01 18:07   ` Sebastian Gniazdowski
2020-07-01 18:12     ` Roman Perepelitsa
2020-07-03 18:12     ` Lewis Butler
2020-07-03 18:35       ` Bart Schaefer
2020-07-01 19:42   ` Peter Stephenson
2020-07-02 11:36     ` Daniel Shahaf
2020-07-02 12:00       ` Peter Stephenson
2020-07-03 16:21         ` Hyphens, minuses, and dashes (was: Re: How to impose a numeric sort on negative numbers?) Daniel Shahaf
2020-07-02 15:46       ` How to impose a numeric sort on negative numbers? Bart Schaefer
2020-07-03 20:08         ` Peter Stephenson [this message]
2020-07-03 20:15           ` Bart Schaefer
2020-07-03 22:23           ` Daniel Shahaf
2020-07-07 16:14             ` Daniel Shahaf
2020-07-07 16:18               ` Daniel Shahaf
2020-07-01 18:48 ` Lawrence Velázquez
2020-07-06  7:15   ` Sebastian Gniazdowski

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