-- This file:
--   http://angg.twu.net/LUA/Lpeg3.lua.html
--   http://angg.twu.net/LUA/Lpeg3.lua
--           (find-angg "LUA/Lpeg3.lua")
-- Author: Eduardo Ochs <eduardoochs@gmail.com>
--
-- (defun e2 () (interactive) (find-angg "LUA/Lpeg2.lua"))
-- (defun e  () (interactive) (find-angg "LUA/Lpeg3.lua"))



lpeg = require("lpeg")

-- (find-es "lpeg" "globals")
B,C,P,R,S,V = lpeg.B,lpeg.C,lpeg.P,lpeg.R,lpeg.S,lpeg.V
Cb,Cc,Cf,Cg = lpeg.Cb,lpeg.Cc,lpeg.Cf,lpeg.Cg
Cp,Cs,Ct    = lpeg.Cp,lpeg.Cs,lpeg.Ct
Carg,Cmt    = lpeg.Carg,lpeg.Cmt

-- (find-angg "LUA/LpegRex1.lua" "rectfromast")
rectfromast = function (o)
    if type(o) == "number" then return Rect.from(o) end
    if type(o) == "string" then return Rect.from(o) end
    if type(o) == "table" then
      local out = rectfromast(o[#o]):syn1()
      for i=#o-2,1,-2 do
        local lowerleft = rectfromast(o[i])
        local left = lowerleft:syn1(o[i+1])
        local left_ = left:pad0(1, left:width()+2, "_")
        out = left_ .. out
      end
      return out
    end
    PP("rectfromast can't handle this", o)
  end

Ast = Class {
  type = "Ast",
  from = function (...) return Ast({...}) end,
  fromsimp = function (...)
      local L = {...}                  -- if ... has a single argument
      if #L == 1 then return L[1] end  -- then return a simplified result.
      return Ast.from(...)
    end,
  __tostring = function (o) return rectfromast(o):tostring() end,
  __index = {
  },
}

-- (find-es "lpeg" "lpeg-quickref")
pskip  = P(" ")^0
pnum   = (R("09")^1):C() * pskip
plit   = function (str) return P(str)     * pskip end
ptok   = function (str) return P(str):C() * pskip end
passoc = function (pexp, ptoks)
    return (pexp * (ptoks * pexp)^0) / Ast.fromsimp
  end
passocs = function (pexpname, ptokstr)
    local pexp = V(pexpname)
    local toknames = split(ptokstr)
    local ptoks = ptok(toknames[1])
    for i=2,#toknames do ptoks = ptoks + ptok(toknames[i]) end
    return (pexp * (ptoks * pexp)^0) / Ast.fromsimp
  end

pexpr = P({
  "add",
   add    = passocs("mul",  "+ -"),
   mul    = passocs("norp", "* /"),
   norp   = pnum + plit("(") * V("add") * plit(")"),
})

--[[
* (eepitch-lua51)
* (eepitch-kill)
* (eepitch-lua51)
dofile "Lpeg3.lua"
= pexpr:match( "1*2 + 3 + 4*5*6 + 7")
= pexpr:match("(1*2 + 3 + 4*5*6 + 7)")
= pexpr:match("(1*2 + 3 + 4*5*6 + 7) * 8")

PPP(pexpr:match( "1*2 + 3 + 4*5*6 + 7"))

--]]




-- Local Variables:
-- coding:  utf-8-unix
-- End: