From: Sebastian Gniazdowski <sgniazdowski@gmail.com>
To: Sebastian Gniazdowski <sgniazdowski@gmail.com>,
Zsh Users <zsh-users@zsh.org>
Subject: Re: Can you loop in math mode?
Date: Mon, 19 Aug 2019 08:41:12 +0200 [thread overview]
Message-ID: <CAKc7PVDO5PecrA43B8fG96V+i0MZOFzs_RGjVP8myWhCuPpFwQ@mail.gmail.com> (raw)
In-Reply-To: <20190819062028.dkewms2nxt37o4te@chaz.gmail.com>
I'm writing a function that computes lengths of the lines in BUFFER
and builds up an array, where each element is a sum of the previous
and the current line / element.
So I have:
integer idx sum
lines_lengths=( ${lines_lengths[@]/(#m)*/$(( sum += ${#MATCH}+1 ))} )
However, I would also like to take into account screen lines, so i.e.
gradually decline ${#MATCH} by COLUMNS bit by bit, assigning a new
element also for each screen-line. Like the following function does:
.zed-compute-llen() {
len=${#1}
while (( len > COLUMNS )) {
sum+=COLUMNS
lines_lengths[++idx]=( $sum )
len=len-COLUMNS
}
sum+=len+1
lines_lengths[++idx]=( $sum )
}
So basically, I would want to do this in the // substitution, like so:
: ${lines_lengths[@]/(#m)*/$(( append(${#MATCH}) ))}
which now thus just resolved :] I don't even need the string-math
function, append should add multiple lines_lengths elements if len >
COLUMNS, that's all.
But thanks for the answer, I think I could use recursion for this too.
On Mon, 19 Aug 2019 at 08:20, Stephane Chazelas
<stephane.chazelas@gmail.com> wrote:
>
> 2019-08-19 02:16:20 +0200, Sebastian Gniazdowski:
> [...]
> > is some kind of a looping possible in math mode?
> [...]
>
> Can you maybe be more specific as to what you're trying to do?
>
> You can use recursion:
>
> $ n=6 a='(n-->1 ? a*(n+1) : 1)' zsh -c 'echo $((a))'
> 720
>
> (6!)
>
> Including via math functions, but within limits.
>
> $ n=0 a='(++n <= 255 ? a+2 : 1)' zsh -c 'echo $((a))'
> zsh:1: math recursion limit exceeded: (++n <= 255 ? a+2 : 1)
>
> And you can of course have command substitutions inside an
> arithmetic expression:
>
> $ echo $(( 1 $(for i ({2..6}) print "*$i") ))
> 720
>
> --
> Stephane
--
Sebastian Gniazdowski
News: https://twitter.com/ZdharmaI
IRC: https://kiwiirc.com/client/chat.freenode.net:+6697/#zplugin
Blog: http://zdharma.org
next prev parent reply other threads:[~2019-08-19 6:42 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAKc7PVDnSqZMpQz=8L5b+SijziN1aUYkm0C-Pv3FMSVy-mg_0Q__8285.33232431568$1566173873$gmane$org@mail.gmail.com>
2019-08-19 6:20 ` Stephane Chazelas
2019-08-19 6:41 ` Sebastian Gniazdowski [this message]
2019-08-19 6:43 ` Sebastian Gniazdowski
2019-08-19 0:16 Sebastian Gniazdowski
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