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- Subject: Re: Next Lua (5.2) feature request : slicing
- From: Mildred <ml.mildred593@...>
- Date: Wed, 22 Nov 2006 00:22:40 +0100
Le mar 21/11/2006 Ã 23:53 Mike Pall Ã Ãcrit:
> Mildred wrote:
> > Why do not add slicing in the next release of Lua ?
> > [...]
> > Any toughts about it ?
Maybe it is possible without adding new opcodes.
IO was just thinking that actually, the  syntax accept only one value
and that it could be possible to put multiples values in there. And
then, the default behaviour would be :
- for tables to extract a part of it
- if the __index metamethod is defined, just give the multiples
values as parameter
Ahd the tab[x:y] syntax would simply be syntaxic shugar for tab[x,y].
It seems very light to me. The idea is just to add support for
multiples values in the  and do something useful with them. But I
don't know lua internals, so maybe it is not. But I think, if it is
easy to do, why not have it ?
Also, in my post, there was something else, indexing strings by default
(change metatable). To be able to do ("abc").
Speaking about strings, I think slicing is much more useful with string
than with tables, so it is a good idea to have it. You can see that
we have a string.sub but no table.sub function :)
The problem with that solution is that slicing assigment is not
possible. Something like a[1:3]=b[2:4], but I don't think it is very
used. And it is still better to have basic slicing than nothing.
Mildred <xmpp:email@example.com> <http://mildred632.free.fr/>
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