-- This file:
--   http://angg.twu.net/LUA/PrecParser1.lua.html
--   http://angg.twu.net/LUA/PrecParser1.lua
--           (find-angg "LUA/PrecParser1.lua")
-- Author: Eduardo Ochs <eduardoochs@gmail.com>
--
-- (defun p  () (interactive) (find-angg "LUA/PrecParser1.lua"))
-- (defun o  () (interactive) (find-angg "LUA/Parenthesize2.lua"))
-- (defun oo () (interactive) (find-angg "LUA/Parenthesize1.lua"))
-- (defun s  () (interactive) (find-angg "LUA/Stack1.lua"))

require "Parenthesize2"      -- (find-angg "LUA/Parenthesize2.lua")
require "Stack1"             -- (find-angg "LUA/Stack1.lua")

numberify = function (str) return str:match("^[0-9]+$") and str+0 or str end

PrecParse = Class {
  type    = "PrecParse",
  new     = function () return PrecParse {} end,
  __tostring = function (pp) return tostring(trees(unpack(pp))) end,
  -- See: (find-es "lua5" "methodsover")
  __index = methodsover(Stack.__index) {
    -- See: (find-angg "LUA/Stack1.lua")
    halfpre   = function (pp) local op   = pp:pop();  return pp:push(pre(op,"?")) end,
    halfbin   = function (pp) local a,op = pp:pop2(); return pp:push(bin(a,op,"?")) end,
    closepre  = function (pp) local a,b  = pp:pop2(); return pp:push(pre(a[0],b)) end,
    closebin  = function (pp) local a,b  = pp:pop2(); return pp:push(bin(a[1], a[0], b)) end,
    closepost = function (pp) local a,op = pp:pop2(); return pp:push(post(a,op)) end,
    --
    orbp1 = function (pp) return opi:orbp(pp:pick(1)) end,  -- use the global opi
    reducep = function (pp, lbp) return #pp>=2 and pp:orbp1()>lbp end,
    reduce1 = function (pp)
        if opi:oprefix(pp:pick(1)) then return pp:closepre() end
        if opi:oinfix (pp:pick(1)) then return pp:closebin() end
        error("bad reduce")
      end,
    reduceforlbp = function (pp, lbp)
        while pp:reducep(lbp) do pp:reduce1() end
        return pp
      end,
    reduceforop = function (pp, op) return pp:reduceforlbp(opi:oplbp(op)) end,
    reduceall   = function (pp, op) return pp:reduceforlbp(0) end,
    --
    half = function (pp)
        if opi:opinfix (pp:pick(0)) then return pp:halfbin() end
        if opi:opprefix(pp:pick(0)) then return pp:halfpre() end
        error("bad half")
      end,
    --
    pushx = function (pp, x)
        if     opi:opinfix  (x) then return pp:reduceforop(x):push(x):half()
        elseif opi:opprefix (x) then return pp               :push(x):half()
        elseif opi:oppostfix(x) then return pp:reduceforop(x):push(x):closepost()
        else return pp:push(x)
        end
      end,
    pushxs = function (pp, str)
        for i,x in ipairs(split(str)) do pp:pushx(numberify(x))
        end
        return pp
      end,
  },
}


--[[
* (eepitch-lua51)
* (eepitch-kill)
* (eepitch-lua51)
dofile "PrecParser1.lua"
s = PrecParse.new()
= s:pushs    (2, "*")
= s:halfbin  ()
= s:pushs    ("u-")
= s:halfpre  ()
= s:pushs    (3)
= s:closepre ()
= s:closebin ()
= s:pushs    ("!")
= s:closepost()

* (eepitch-lua51)
* (eepitch-kill)
* (eepitch-lua51)
dofile "PrecParser1.lua"
s = PrecParse.new()
= opi:opinfo("+")
= opi:oplbp("+")
= opi:oprbp("+")
= opi:oplbp("!")
= opi:oprbp("!")
= opi:oplbp("u-")
= opi:oprbp("u-")

* (eepitch-lua51)
* (eepitch-kill)
* (eepitch-lua51)
dofile "PrecParser1.lua"
s = PrecParse.new()
= s:pushs(1)
= s:pushs("+"):halfbin()
= s:pushs(2)
= s:pushs("+"):halfbin()
= s:pushs(3)
= s:pushs("^"):halfbin()
= s:pushs(4)
= s:pushs("^"):halfbin()
= s:pushs(5)
= s:pushs("^"):halfbin()
= s:pushs(6)
= s:reduceforop("*")
= s:reduceall()

* (eepitch-lua51)
* (eepitch-kill)
* (eepitch-lua51)
dofile "PrecParser1.lua"
s = PrecParse.new()
= s:pushx(2)
= s:pushx("*")
= s:pushx(3)
= s:pushx("+")
= s:pushx("u-")
= s:pushx(4)
= s:pushx("!")
= s:pushx("^")
= s:pushx(5)
= s:pushx("+")

s = PrecParse.new()
= s:pushxs("2 * 3 + u- 4 ! ^ 5 +")
= s:pushxs("6 + 7")
= s:reduceall()
= s[1]
= opi:text(s[1])

--]]






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