-- $Id: grammar1.lua,v 1.7 2008/08/22 10:11:19 hahe Exp $

require "lpeg"

txt = "( (123) (1(abc) 23))"

ob = lpeg.P("(")
cb = lpeg.P(")")

pat = lpeg.P{
  "braced",
  braced = ob * lpeg.V("inside") * cb,
  inside = (lpeg.V("innermost") + lpeg.V("braced") + (1 - (ob + cb)))^0,
  innermost = ob * lpeg.C((1 - (ob + cb))^0) * cb,
}

pat = pat * lpeg.P(-1)

pat = lpeg.Ct(pat)

x = lpeg.match(pat, txt)

for k, v in pairs(x) do
  print(k, v)
end