Re: Nested table constructor with reference to other children

[Philipp Janda <siffiejoe@...>]

On 30.10.2011 15:39, Marc Balmer wrote:
> Hi

Hi!

> I am trying create a table with subtables, where subtables reference
> each other, using the table constructor syntax:
>
> a = {
>    one = {
>      a = 1,
>      b = 2
>    },
>    two = {
>      a = 1,
>      b = one  -- set's b to nil
>    }
> }
>
> Is there a way to write this constructor, so that a.two.b is set to
> a.one instead of nil?  Or do I have to fixup the table after construction?

The best I can come up with is this:
$ cat > ref.lua
local temp = {}
local function v( s )
  return function( t )
    temp[ s ] = t
  end
end
local function r( s )
  return temp[ s ]
end

a = {
  one = v"one"{
    a = 1,
    b = 2
  },
  two = {
    a = 1,
    b = r"one"
  }
}

print( a.two.b.a )
^D

It seems to work, but I didn't find any guarantees about table 
constructor evaluation order by quickly skimming the ref manual ...

> Thanks,
> Marc

Philipp