-- This file:
--   http://anggtwu.net/LUA/PegDebug1.lua.html
--   http://anggtwu.net/LUA/PegDebug1.lua
--          (find-angg "LUA/PegDebug1.lua")
-- Author: Eduardo Ochs <eduardoochs@gmail.com>
--
-- (defun e () (interactive) (find-angg "LUA/PegDebug1.lua"))
-- (find-es "lpeg" "pegdebug0")
-- (find-es "lpeg" "pegdebug")
-- Moved to: (find-angg "LUA/Gram2.lua" "LpegDebug")


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




pegdebug = {
  _NAME = "pegdebug",
  _VERSION = 0.41,
  _COPYRIGHT = "Paul Kulchenko",
  _DESCRIPTION = "Debugger for LPeg expressions and processing",
}

function pegdebug.trace(grammar, opts)
  opts = opts or {}
  local function line(s) return (string.format("%q", s):gsub("\\\n", "\\n")) end
  local function pretty(...)
    -- if serpent then return serpent({...}, {comment = false}):sub(2,-2) end
    local res = {}
    for i = 1, select('#', ...) do
      local v = select(i, ...)
      local tv = type(v)
      res[i] = tv == 'number' and v or tv == 'string' and line(v) or tostring(v)
    end
    return table.concat(res, ", ")
  end
  local level = 0
  local start = {}
  local print = print
  if type(opts.out) == 'table' then
    print = function(...) table.insert(opts.out, table.concat({...}, "\t")) end
  end
  for k, p in pairs(grammar) do
    local enter = Cmt(P(true), function(s, p, ...)
        start[level] = p
        if opts['+'] ~= false then
          print((" "):rep(level).."+", k, p, line(s:sub(p,p)))
        end
        level = level + 1
        return true
      end)
    local leave = Cmt(P(true), function(s, p, ...)
        level = level - 1
        if opts['-'] ~= false then
          print((" "):rep(level).."-", k, p)
        end
        return true
      end) * (P(1) - P(1))
    local eq = Cmt(P(true), function(s, p, ...)
        level = level - 1
        if opts['='] ~= false then
          print((" "):rep(level).."=", k, start[level]..'-'..(p-1), line(s:sub(start[level],p-1)))
        end
        return true
      end)
    if k ~= 1 and (not opts.only or opts.only[k]) then
      if opts['/'] ~= false
      and (type(opts['/']) ~= 'table' or opts['/'][k] ~= false) then
        -- Cp() is needed to only get captures (and not the whole match)
        p = Cp() * p / function(pos, ...)
            print((" "):rep(level).."/", k, pos, select('#', ...), pretty(...))
            return ...
          end
      end
      grammar[k] = enter * p * eq + leave
    end
  end
  return grammar
end

-- return pegdebug

LpegDebug = Class {
  type = "LpegDebug",
  from = function (name)
      return LpegDebug {name=name}
    end,
  __tostring = function (lpd) return mytostringp(lpd) end,
  __index = {
    subst = function (lpd, fmt, pos)
        local name = lpd.name
        local A = {name=name, pos=pos}
        return (fmt:gsub("<(.-)>", A))
      end,
    f = function (lpd, fmt)
        return function (subj,pos,...)
            printf(lpd:subst(fmt, pos))
            return pos,...
          end
      end,
    cmt0  = function (lpd, fmt, pat) return pat:Cmt(lpd:f(fmt)) end,
    cmtt  = function (lpd, fmt) return lpd:cmt0(fmt, lpeg.P(true)) end,
    pbeg  = function (lpd) return lpd:cmtt("(<name>:<pos>\n") end,
    pmid  = function (lpd) return lpd:cmtt(" <name>:<pos>\n") end,
    pend  = function (lpd) return lpd:cmtt(" <name>:<pos>)\n") end,
    pfail = function (lpd) return lpd:cmtt(" <name>:fail)\n") end,
    dbg   = function (lpd, pat)
        return lpd:pbeg()*pat*lpd:pend()
             + lpd:pfail()*P(false)
      end,
  },
}



--[[
* (eepitch-lua51)
* (eepitch-kill)
* (eepitch-lua51)
dofile "PegDebug1.lua"
lpd = LpegDebug.from("A")
= lpd
= lpd:subst("foo")
= lpd:subst("foo<name>")
= lpd:subst("foo<name><pos>.", 42)

pa = P"aa":Cs()
pb = P"bb":Cs()
pt = P(true)
pbeg  = lpd:pbeg()
pmid  = lpd:pmid()
pend  = lpd:pend()
pfail = lpd:pfail()
pbeg = lpd:pbeg()
pbeg = lpd:cmtt("(<name>:<pos>\n")
pmid = lpd:cmtt(" <name>:<pos>\n")
pend = lpd:cmtt(" <name>:<pos>)\n")

= (pa*pb) : match("aabbcc")
= (pbeg*pa*pmid*pb*pend) : match("aabbcc")
= lpd:dbg(pa*pb)  : match("aabbcc")
= lpd:dbg(pa*pb)  : match("aacc")
=        (pa*pb)  : match("aacc")

ldebug = function (name, pat) return LpegDebug.from(name):dbg(pat) end

= ldebug("ab", pa*pb) : match("aabbcc")
= ldebug("ab", pa*pb) : match("aac")

--]]







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