Re: Request for 5.4: adding [] as table creation syntax for Lua 6.0

[Rena <hyperhacker@...>]

On Jul 12, 2016 4:36 PM, "Luiz Henrique de Figueiredo" <lhf@tecgraf.puc-rio.br> wrote:
>
> > I think there was a huge missed opportunity here. [] actually looks like a
> > table!
>
> It was like that in Lua 1:
>         a = @f[ 10, 20, 30]
> was the same as
>         t = { 10, 20, 30 }
>         f(t)
>         a = t
> See
>         https://www.lua.org/ftp/refman-1.1.ps.gz
>         https://www.lua.org/semish94.html
>         section "Data types and variables"
>

If there were going to be new syntax, I feel it'd go well with the discussion of arrays:

t = {x, y, z} --same as current meaning
a = [x, y, z] --means: a = array(x, y, z)
Where array() is something like:

function array(...)
  local t = {...}
  return setmetatable(t, {
    __n = select('#', ...),
    __index = <snip>,
    __newindex = <snip>,
    ...etc...
  })
end

I think Lua would benefit from a "standard" array type, even if it is just a table. (Being standard does also mean the possibility to use a more optimal internal representation.) When everyone rolls their own, interoperability is difficult.