Re: String argification

[Duncan Cross <duncan.cross@...>]

On Sun, Feb 27, 2011 at 3:07 PM, David Given <dg@cowlark.com> wrote:
> Does anyone have a cunning piece of pure-Lua code for argifying a
> string? That is, turning this:
>
>        foo bar "baz bloo \"fnord" wibble
>
> into this:
>
>        {'foo', 'bar', 'baz bloo "fnord', 'wibble'}
>
> ...?
>
> I've had a look at the wiki, as this is a fairly stock problem, but
> don't see anything.
>

Probably not especially cunning, but this is my attempt:

  --
  function argify(str)
    local output = {}
    local i = 1 -- current position
    local m     -- temporary match value
    while i <= #str do
      i, m = str:match('%s*()(%S)', i)
      if not m then -- trailing whitespace
        break
      end
      if m == [["]] then
        local j = i + 1
        repeat
          m, j = str:match('(\\?)"()', j)
          if not m then
            error('argify: mismatched quote', 2)
          end
        until (#m == 0)
        output[#output+1] = str:sub(i+1,j-2):gsub('\\"', '"')
        i = j
      else
        output[#output+1], i = str:match('(%S+)()', i)
      end
    end
    return output
  end
  --

-Duncan