-- This file:
--   http://angg.twu.net/LUA/Arith4.lua.html
--   http://angg.twu.net/LUA/Arith4.lua
--           (find-angg "LUA/Arith4.lua")
-- Author: Eduardo Ochs <eduardoochs@gmail.com>
--
-- (defun a () (interactive) (find-angg "LUA/Arith4.lua"))
-- (find-es "lpeg" "lpegrex")
-- (find-lpegrexpage)
-- (find-lpegrextext)
-- (find-lpegrexfile "parsers/lua.lua")

Path.prepend("cpath", "~/usrc/lpeglabel/?.so")
Path.prepend("path",  "~/usrc/lpegrex/?.lua")
lpegrex = require "lpegrex"

Grammar = [==[
  top           <-- plusexpr
  plusexpr      <-| timesexpr ({"+"} timesexpr)*
  timesexpr     <-| norp      ({"*"} norp)*
  norp          <-| num     / ("(" plusexpr ")") 
  num           <-- {%d}
]==]

Grammar = [==[
top           <-- expr

SKIP          <-  %s+
Id            <== NAME
NAME          <-- {NAME_PREFIX NAME_SUFFIX?} SKIP
NAME_PREFIX   <-- [_a-zA-Z]
NAME_SUFFIX   <-- [_a-zA-Z0-9]+
Nil           <== `nil`

opor     :BinaryOp <== `or`->'or' @exprand
opand    :BinaryOp <== `and`->'and' @exprcmp
opcmp    :BinaryOp <== (`==`->'eq' / `~=`->'ne' / `<=`->'le' / `>=`->'ge' / `<`->'lt' / `>`->'gt') @exprbor
opbor    :BinaryOp <== `|`->'bor' @exprbxor
opbxor   :BinaryOp <== `~`->'bxor' @exprband
opband   :BinaryOp <== `&`->'band' @exprbshift
opbshift :BinaryOp <== (`<<`->'shl' / `>>`->'shr') @exprconcat
opconcat :BinaryOp <== `..`->'concat' @exprconcat
oparit   :BinaryOp <== (`+`->'add' / `-`->'sub') @exprfact
opfact   :BinaryOp <== (`*`->'mul' / `//`->'idiv' / `/`->'div' / `%`->'mod') @exprunary
oppow    :BinaryOp <== `^`->'pow' @exprunary
opunary  :UnaryOp  <== (`not`->'not' / `#`->'len' / `-`->'unm' / `~`->'bnot') @exprunary

Paren         <== `(` @expr @`)`

expr          <-- expror
expror        <-- (exprand opor*)~>foldleft
exprand       <-- (exprcmp opand*)~>foldleft
exprcmp       <-- (exprbor opcmp*)~>foldleft
exprbor       <-- (exprbxor opbor*)~>foldleft
exprbxor      <-- (exprband opbxor*)~>foldleft
exprband      <-- (exprbshift opband*)~>foldleft
exprbshift    <-- (exprconcat opbshift*)~>foldleft
exprconcat    <-- (exprarit opconcat*)~>foldleft
exprarit      <-- (exprfact oparit*)~>foldleft
exprfact      <-- (exprunary opfact*)~>foldleft
exprunary     <-- opunary / exprpow
exprpow       <-- (exprsimple oppow*)~>foldleft
exprsimple    <-- [0-9]+
exprprimary   <-- Id / Paren

]==]



patt = lpegrex.compile(Grammar)
bigstr = "(1+2)*3"
ast, errlabel, errpos = patt:match(bigstr)
PPPV(ast, errlabel, errpos)



--[[
* (eepitch-lua52)
* (eepitch-kill)
* (eepitch-lua52)
dofile "Arith4.lua"

--]]




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-- coding:  utf-8-unix
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