[TxMt] Matching nested pairs

[Gavin Kistner]

I decided to just make my own Lua module, by hacking an existing  
module and (for now) making up my own UUID. I'm 95% done, but for two  
(related) issues:

In Lua, you can have a multi-line string delimited by [[ ... ]]. For  
example:

local theMessage = [[
Hello world
How are you doing?
]]

I've got that one covered. However, Lua is tricky and allows you to  
have nested [[..]] pairs within this block. So, for example:

local theExample = [[
Hello world
In Lua, a string can contain nested [[...]] pairs.
This includes a case like [[ hi [[ there ]] ]]
More string]]

Is it possible to do this? I don't think so in general PCRE, but  
didn't know if TextMate or Oniguruma had some sweet balancing.

Right now I have:
         {    name = 'string.quoted.multiline.lua';
             begin = '(?<!--)\[\[';
             end = '\]\]';
             swallow = '\[\[(.|\r)*?\]\]|\\.';
         },
which handles a single pair of [[..]] on the same line inside a  
block, but doesn't handle multiple nesting or (for reasons I don't  
understand) handle a single pair across multiple lines. Where can I  
find more information on the 'swallow' bit?