Re: "${*:offset:length}" and ksh93/bash compatibility

[Mikael Magnusson <mikachu@xxxxxxxxx>]

On 3/10/22, Peter Stephenson <p.w.stephenson@xxxxxxxxxxxx> wrote:
> On 10 March 2022 at 12:48 Mikael Magnusson <mikachu@xxxxxxxxx> wrote:
>> On 3/10/22, Stephane Chazelas <stephane@xxxxxxxxxxxx> wrote:
>> > Should zsh align with bash/ksh there.
>>
>> If we do, it would probably look something like this (does not handle
>> all cases), unless someone has a better idea...
>
> I think it should change --- the documentation is already clear this is
> here to please users of other shells, not native zsh.  Otherwise we end
> up with what's (as we say where I come from) neither nowt nor something.
>
>   This  syntax  gives  effects  similar to parameter subscripting in the
> form
>   $name[start,end], but is compatible with other shells; note that both
> off‐
>   set  and  length  are interpreted differently from the components of a
> sub‐
>   script.

I realized that this is not limited to $*,

zsh% a=(one two three); echo "${a[@]:0:2}"
one two
zsh% a=(one two three); echo "${a[*]:0:2}"
on
zsh% bash -c 'a=(one two three); echo "${a[@]:0:2}"'
one two
zsh% bash -c 'a=(one two three); echo "${a[*]:0:2}"'
one two

So perhaps this should be attacked in a different place/way than my
test patch (though i think the horrible offset hack is still needed
for $*:0 specifically (and i actually didn't even handle that in the
patch anyway.).)

-- 
Mikael Magnusson