contrib, build: bundle LuaSrcDiet and make it available in build targets

7 files changed, 3756 insertions, 0 deletions

diff --git a/contrib/luasrcdiet/Makefile b/contrib/luasrcdiet/Makefile
new file mode 100644
index 000000000..81a96f6a8
--- /dev/null
+++ b/contrib/luasrcdiet/Makefile
@@ -0,0 +1,2 @@
+include ../../build/config.mk
+include ../../build/module.mk
\ No newline at end of file
diff --git a/contrib/luasrcdiet/lua/COPYRIGHT b/contrib/luasrcdiet/lua/COPYRIGHT
new file mode 100644
index 000000000..b91ffa8d4
--- /dev/null
+++ b/contrib/luasrcdiet/lua/COPYRIGHT
@@ -0,0 +1,38 @@
+LuaSrcDiet License
+------------------
+
+LuaSrcDiet is licensed under the terms of the MIT license reproduced
+below. This means that LuaSrcDiet is free software and can be used for
+both academic and commercial purposes at absolutely no cost.
+
+Parts of LuaSrcDiet is based on Lua 5 code. See COPYRIGHT_Lua51
+(Lua 5.1.3) for Lua 5 license information.
+
+For details and rationale, see http://www.lua.org/license.html .
+
+===============================================================================
+
+Copyright (C) 2005-2008 Kein-Hong Man <khman@users.sf.net>
+Lua 5.1.3 Copyright (C) 1994-2008 Lua.org, PUC-Rio.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+===============================================================================
+
+(end of COPYRIGHT)
diff --git a/contrib/luasrcdiet/lua/LuaSrcDiet.lua b/contrib/luasrcdiet/lua/LuaSrcDiet.lua
new file mode 100755
index 000000000..d9a41f24b
--- /dev/null
+++ b/contrib/luasrcdiet/lua/LuaSrcDiet.lua
@@ -0,0 +1,670 @@
+#!/usr/bin/env lua
+--[[--------------------------------------------------------------------
+
+  LuaSrcDiet
+  Compresses Lua source code by removing unnecessary characters.
+  For Lua 5.1.x source code.
+
+  Copyright (c) 2008 Kein-Hong Man <khman@users.sf.net>
+  The COPYRIGHT file describes the conditions
+  under which this software may be distributed.
+
+  See the ChangeLog for more information.
+
+----------------------------------------------------------------------]]
+
+--[[--------------------------------------------------------------------
+-- NOTES:
+-- * Remember to update version and date information below (MSG_TITLE)
+-- * TODO: to implement pcall() to properly handle lexer etc. errors
+-- * TODO: verify token stream or double-check binary chunk?
+-- * TODO: need some automatic testing for a semblance of sanity
+-- * TODO: the plugin module is highly experimental and unstable
+----------------------------------------------------------------------]]
+
+-- standard libraries, functions
+local string = string
+local math = math
+local table = table
+local require = require
+local print = print
+local sub = string.sub
+local gmatch = string.gmatch
+
+-- support modules
+local llex = require "llex"
+local lparser = require "lparser"
+local optlex = require "optlex"
+local optparser = require "optparser"
+local plugin
+
+--[[--------------------------------------------------------------------
+-- messages and textual data
+----------------------------------------------------------------------]]
+
+local MSG_TITLE = [[
+LuaSrcDiet: Puts your Lua 5.1 source code on a diet
+Version 0.11.2 (20080608)  Copyright (c) 2005-2008 Kein-Hong Man
+The COPYRIGHT file describes the conditions under which this
+software may be distributed.
+]]
+
+local MSG_USAGE = [[
+usage: LuaSrcDiet [options] [filenames]
+
+example:
+  >LuaSrcDiet myscript.lua -o myscript_.lua
+
+options:
+  -v, --version       prints version information
+  -h, --help          prints usage information
+  -o <file>           specify file name to write output
+  -s <suffix>         suffix for output files (default '_')
+  --keep <msg>        keep block comment with <msg> inside
+  --plugin <module>   run <module> in plugin/ directory
+  -                   stop handling arguments
+
+  (optimization levels)
+  --none              all optimizations off (normalizes EOLs only)
+  --basic             lexer-based optimizations only
+  --maximum           maximize reduction of source
+
+  (informational)
+  --quiet             process files quietly
+  --read-only         read file and print token stats only
+  --dump-lexer        dump raw tokens from lexer to stdout
+  --dump-parser       dump variable tracking tables from parser
+  --details           extra info (strings, numbers, locals)
+
+features (to disable, insert 'no' prefix like --noopt-comments):
+%s
+default settings:
+%s]]
+
+------------------------------------------------------------------------
+-- optimization options, for ease of switching on and off
+-- * positive to enable optimization, negative (no) to disable
+-- * these options should follow --opt-* and --noopt-* style for now
+------------------------------------------------------------------------
+
+local OPTION = [[
+--opt-comments,'remove comments and block comments'
+--opt-whitespace,'remove whitespace excluding EOLs'
+--opt-emptylines,'remove empty lines'
+--opt-eols,'all above, plus remove unnecessary EOLs'
+--opt-strings,'optimize strings and long strings'
+--opt-numbers,'optimize numbers'
+--opt-locals,'optimize local variable names'
+--opt-entropy,'tries to reduce symbol entropy of locals'
+]]
+
+-- preset configuration
+local DEFAULT_CONFIG = [[
+  --opt-comments --opt-whitespace --opt-emptylines
+  --opt-numbers --opt-locals
+]]
+-- override configurations: MUST explicitly enable/disable everything
+local BASIC_CONFIG = [[
+  --opt-comments --opt-whitespace --opt-emptylines
+  --noopt-eols --noopt-strings --noopt-numbers
+  --noopt-locals
+]]
+local MAXIMUM_CONFIG = [[
+  --opt-comments --opt-whitespace --opt-emptylines
+  --opt-eols --opt-strings --opt-numbers
+  --opt-locals --opt-entropy
+]]
+local NONE_CONFIG = [[
+  --noopt-comments --noopt-whitespace --noopt-emptylines
+  --noopt-eols --noopt-strings --noopt-numbers
+  --noopt-locals
+]]
+
+local DEFAULT_SUFFIX = "_"      -- default suffix for file renaming
+local PLUGIN_SUFFIX = "plugin/" -- relative location of plugins
+
+--[[--------------------------------------------------------------------
+-- startup and initialize option list handling
+----------------------------------------------------------------------]]
+
+-- simple error message handler; change to error if traceback wanted
+local function die(msg)
+  print("LuaSrcDiet: "..msg); os.exit()
+end
+--die = error--DEBUG
+
+if not string.match(_VERSION, "5.1", 1, 1) then  -- sanity check
+  die("requires Lua 5.1 to run")
+end
+
+------------------------------------------------------------------------
+-- prepares text for list of optimizations, prepare lookup table
+------------------------------------------------------------------------
+
+local MSG_OPTIONS = ""
+do
+  local WIDTH = 24
+  local o = {}
+  for op, desc in gmatch(OPTION, "%s*([^,]+),'([^']+)'") do
+    local msg = "  "..op
+    msg = msg..string.rep(" ", WIDTH - #msg)..desc.."\n"
+    MSG_OPTIONS = MSG_OPTIONS..msg
+    o[op] = true
+    o["--no"..sub(op, 3)] = true
+  end
+  OPTION = o  -- replace OPTION with lookup table
+end
+
+MSG_USAGE = string.format(MSG_USAGE, MSG_OPTIONS, DEFAULT_CONFIG)
+
+------------------------------------------------------------------------
+-- global variable initialization, option set handling
+------------------------------------------------------------------------
+
+local suffix = DEFAULT_SUFFIX           -- file suffix
+local option = {}                       -- program options
+local stat_c, stat_l                    -- statistics tables
+
+-- function to set option lookup table based on a text list of options
+-- note: additional forced settings for --opt-eols is done in optlex.lua
+local function set_options(CONFIG)
+  for op in gmatch(CONFIG, "(%-%-%S+)") do
+    if sub(op, 3, 4) == "no" and        -- handle negative options
+       OPTION["--"..sub(op, 5)] then
+      option[sub(op, 5)] = false
+    else
+      option[sub(op, 3)] = true
+    end
+  end
+end
+
+--[[--------------------------------------------------------------------
+-- support functions
+----------------------------------------------------------------------]]
+
+-- list of token types, parser-significant types are up to TTYPE_GRAMMAR
+-- while the rest are not used by parsers; arranged for stats display
+local TTYPES = {
+  "TK_KEYWORD", "TK_NAME", "TK_NUMBER",         -- grammar
+  "TK_STRING", "TK_LSTRING", "TK_OP",
+  "TK_EOS",
+  "TK_COMMENT", "TK_LCOMMENT",                  -- non-grammar
+  "TK_EOL", "TK_SPACE",
+}
+local TTYPE_GRAMMAR = 7
+
+local EOLTYPES = {                      -- EOL names for token dump
+  ["\n"] = "LF", ["\r"] = "CR",
+  ["\n\r"] = "LFCR", ["\r\n"] = "CRLF",
+}
+
+------------------------------------------------------------------------
+-- read source code from file
+------------------------------------------------------------------------
+
+local function load_file(fname)
+  local INF = io.open(fname, "rb")
+  if not INF then die("cannot open \""..fname.."\" for reading") end
+  local dat = INF:read("*a")
+  if not dat then die("cannot read from \""..fname.."\"") end
+  INF:close()
+  return dat
+end
+
+------------------------------------------------------------------------
+-- save source code to file
+------------------------------------------------------------------------
+
+local function save_file(fname, dat)
+  local OUTF = io.open(fname, "wb")
+  if not OUTF then die("cannot open \""..fname.."\" for writing") end
+  local status = OUTF:write(dat)
+  if not status then die("cannot write to \""..fname.."\"") end
+  OUTF:close()
+end
+
+------------------------------------------------------------------------
+-- functions to deal with statistics
+------------------------------------------------------------------------
+
+-- initialize statistics table
+local function stat_init()
+  stat_c, stat_l = {}, {}
+  for i = 1, #TTYPES do
+    local ttype = TTYPES[i]
+    stat_c[ttype], stat_l[ttype] = 0, 0
+  end
+end
+
+-- add a token to statistics table
+local function stat_add(tok, seminfo)
+  stat_c[tok] = stat_c[tok] + 1
+  stat_l[tok] = stat_l[tok] + #seminfo
+end
+
+-- do totals for statistics table, return average table
+local function stat_calc()
+  local function avg(c, l)                      -- safe average function
+    if c == 0 then return 0 end
+    return l / c
+  end
+  local stat_a = {}
+  local c, l = 0, 0
+  for i = 1, TTYPE_GRAMMAR do                   -- total grammar tokens
+    local ttype = TTYPES[i]
+    c = c + stat_c[ttype]; l = l + stat_l[ttype]
+  end
+  stat_c.TOTAL_TOK, stat_l.TOTAL_TOK = c, l
+  stat_a.TOTAL_TOK = avg(c, l)
+  c, l = 0, 0
+  for i = 1, #TTYPES do                         -- total all tokens
+    local ttype = TTYPES[i]
+    c = c + stat_c[ttype]; l = l + stat_l[ttype]
+    stat_a[ttype] = avg(stat_c[ttype], stat_l[ttype])
+  end
+  stat_c.TOTAL_ALL, stat_l.TOTAL_ALL = c, l
+  stat_a.TOTAL_ALL = avg(c, l)
+  return stat_a
+end
+
+--[[--------------------------------------------------------------------
+-- main tasks
+----------------------------------------------------------------------]]
+
+------------------------------------------------------------------------
+-- a simple token dumper, minimal translation of seminfo data
+------------------------------------------------------------------------
+
+local function dump_tokens(srcfl)
+  --------------------------------------------------------------------
+  -- load file and process source input into tokens
+  --------------------------------------------------------------------
+  local z = load_file(srcfl)
+  llex.init(z)
+  llex.llex()
+  local toklist, seminfolist = llex.tok, llex.seminfo
+  --------------------------------------------------------------------
+  -- display output
+  --------------------------------------------------------------------
+  for i = 1, #toklist do
+    local tok, seminfo = toklist[i], seminfolist[i]
+    if tok == "TK_OP" and string.byte(seminfo) < 32 then
+      seminfo = "(".. string.byte(seminfo)..")"
+    elseif tok == "TK_EOL" then
+      seminfo = EOLTYPES[seminfo]
+    else
+      seminfo = "'"..seminfo.."'"
+    end
+    print(tok.." "..seminfo)
+  end--for
+end
+
+----------------------------------------------------------------------
+-- parser dump; dump globalinfo and localinfo tables
+----------------------------------------------------------------------
+
+local function dump_parser(srcfl)
+  local print = print
+  --------------------------------------------------------------------
+  -- load file and process source input into tokens
+  --------------------------------------------------------------------
+  local z = load_file(srcfl)
+  llex.init(z)
+  llex.llex()
+  local toklist, seminfolist, toklnlist
+    = llex.tok, llex.seminfo, llex.tokln
+  --------------------------------------------------------------------
+  -- do parser optimization here
+  --------------------------------------------------------------------
+  lparser.init(toklist, seminfolist, toklnlist)
+  local globalinfo, localinfo = lparser.parser()
+  --------------------------------------------------------------------
+  -- display output
+  --------------------------------------------------------------------
+  local hl = string.rep("-", 72)
+  print("*** Local/Global Variable Tracker Tables ***")
+  print(hl.."\n GLOBALS\n"..hl)
+  -- global tables have a list of xref numbers only
+  for i = 1, #globalinfo do
+    local obj = globalinfo[i]
+    local msg = "("..i..") '"..obj.name.."' -> "
+    local xref = obj.xref
+    for j = 1, #xref do msg = msg..xref[j].." " end
+    print(msg)
+  end
+  -- local tables have xref numbers and a few other special
+  -- numbers that are specially named: decl (declaration xref),
+  -- act (activation xref), rem (removal xref)
+  print(hl.."\n LOCALS (decl=declared act=activated rem=removed)\n"..hl)
+  for i = 1, #localinfo do
+    local obj = localinfo[i]
+    local msg = "("..i..") '"..obj.name.."' decl:"..obj.decl..
+                " act:"..obj.act.." rem:"..obj.rem
+    if obj.isself then
+      msg = msg.." isself"
+    end
+    msg = msg.." -> "
+    local xref = obj.xref
+    for j = 1, #xref do msg = msg..xref[j].." " end
+    print(msg)
+  end
+  print(hl.."\n")
+end
+
+------------------------------------------------------------------------
+-- reads source file(s) and reports some statistics
+------------------------------------------------------------------------
+
+local function read_only(srcfl)
+  local print = print
+  --------------------------------------------------------------------
+  -- load file and process source input into tokens
+  --------------------------------------------------------------------
+  local z = load_file(srcfl)
+  llex.init(z)
+  llex.llex()
+  local toklist, seminfolist = llex.tok, llex.seminfo
+  print(MSG_TITLE)
+  print("Statistics for: "..srcfl.."\n")
+  --------------------------------------------------------------------
+  -- collect statistics
+  --------------------------------------------------------------------
+  stat_init()
+  for i = 1, #toklist do
+    local tok, seminfo = toklist[i], seminfolist[i]
+    stat_add(tok, seminfo)
+  end--for
+  local stat_a = stat_calc()
+  --------------------------------------------------------------------
+  -- display output
+  --------------------------------------------------------------------
+  local fmt = string.format
+  local function figures(tt)
+    return stat_c[tt], stat_l[tt], stat_a[tt]
+  end
+  local tabf1, tabf2 = "%-16s%8s%8s%10s", "%-16s%8d%8d%10.2f"
+  local hl = string.rep("-", 42)
+  print(fmt(tabf1, "Lexical",  "Input", "Input", "Input"))
+  print(fmt(tabf1, "Elements", "Count", "Bytes", "Average"))
+  print(hl)
+  for i = 1, #TTYPES do
+    local ttype = TTYPES[i]
+    print(fmt(tabf2, ttype, figures(ttype)))
+    if ttype == "TK_EOS" then print(hl) end
+  end
+  print(hl)
+  print(fmt(tabf2, "Total Elements", figures("TOTAL_ALL")))
+  print(hl)
+  print(fmt(tabf2, "Total Tokens", figures("TOTAL_TOK")))
+  print(hl.."\n")
+end
+
+------------------------------------------------------------------------
+-- process source file(s), write output and reports some statistics
+------------------------------------------------------------------------
+
+local function process_file(srcfl, destfl)
+  local function print(...)             -- handle quiet option
+    if option.QUIET then return end
+    _G.print(...)
+  end
+  if plugin and plugin.init then        -- plugin init
+    option.EXIT = false
+    plugin.init(option, srcfl, destfl)
+    if option.EXIT then return end
+  end
+  print(MSG_TITLE)                      -- title message
+  --------------------------------------------------------------------
+  -- load file and process source input into tokens
+  --------------------------------------------------------------------
+  local z = load_file(srcfl)
+  if plugin and plugin.post_load then   -- plugin post-load
+    z = plugin.post_load(z) or z
+    if option.EXIT then return end
+  end
+  llex.init(z)
+  llex.llex()
+  local toklist, seminfolist, toklnlist
+    = llex.tok, llex.seminfo, llex.tokln
+  if plugin and plugin.post_lex then    -- plugin post-lex
+    plugin.post_lex(toklist, seminfolist, toklnlist)
+    if option.EXIT then return end
+  end
+  --------------------------------------------------------------------
+  -- collect 'before' statistics
+  --------------------------------------------------------------------
+  stat_init()
+  for i = 1, #toklist do
+    local tok, seminfo = toklist[i], seminfolist[i]
+    stat_add(tok, seminfo)
+  end--for
+  local stat1_a = stat_calc()
+  local stat1_c, stat1_l = stat_c, stat_l
+  --------------------------------------------------------------------
+  -- do parser optimization here
+  --------------------------------------------------------------------
+  if option["opt-locals"] then
+    optparser.print = print  -- hack
+    lparser.init(toklist, seminfolist, toklnlist)
+    local globalinfo, localinfo = lparser.parser()
+    if plugin and plugin.post_parse then        -- plugin post-parse
+      plugin.post_parse(globalinfo, localinfo)
+      if option.EXIT then return end
+    end
+    optparser.optimize(option, toklist, seminfolist, globalinfo, localinfo)
+    if plugin and plugin.post_optparse then     -- plugin post-optparse
+      plugin.post_optparse()
+      if option.EXIT then return end
+    end
+  end
+  --------------------------------------------------------------------
+  -- do lexer optimization here, save output file
+  --------------------------------------------------------------------
+  optlex.print = print  -- hack
+  toklist, seminfolist, toklnlist
+    = optlex.optimize(option, toklist, seminfolist, toklnlist)
+  if plugin and plugin.post_optlex then         -- plugin post-optlex
+    plugin.post_optlex(toklist, seminfolist, toklnlist)
+    if option.EXIT then return end
+  end
+  local dat = table.concat(seminfolist)
+  -- depending on options selected, embedded EOLs in long strings and
+  -- long comments may not have been translated to \n, tack a warning
+  if string.find(dat, "\r\n", 1, 1) or
+     string.find(dat, "\n\r", 1, 1) then
+    optlex.warn.mixedeol = true
+  end
+  -- save optimized source stream to output file
+  save_file(destfl, dat)
+  --------------------------------------------------------------------
+  -- collect 'after' statistics
+  --------------------------------------------------------------------
+  stat_init()
+  for i = 1, #toklist do
+    local tok, seminfo = toklist[i], seminfolist[i]
+    stat_add(tok, seminfo)
+  end--for
+  local stat_a = stat_calc()
+  --------------------------------------------------------------------
+  -- display output
+  --------------------------------------------------------------------
+  print("Statistics for: "..srcfl.." -> "..destfl.."\n")
+  local fmt = string.format
+  local function figures(tt)
+    return stat1_c[tt], stat1_l[tt], stat1_a[tt],
+           stat_c[tt],  stat_l[tt],  stat_a[tt]
+  end
+  local tabf1, tabf2 = "%-16s%8s%8s%10s%8s%8s%10s",
+                       "%-16s%8d%8d%10.2f%8d%8d%10.2f"
+  local hl = string.rep("-", 68)
+  print("*** lexer-based optimizations summary ***\n"..hl)
+  print(fmt(tabf1, "Lexical",
+            "Input", "Input", "Input",
+            "Output", "Output", "Output"))
+  print(fmt(tabf1, "Elements",
+            "Count", "Bytes", "Average",
+            "Count", "Bytes", "Average"))
+  print(hl)
+  for i = 1, #TTYPES do
+    local ttype = TTYPES[i]
+    print(fmt(tabf2, ttype, figures(ttype)))
+    if ttype == "TK_EOS" then print(hl) end
+  end
+  print(hl)
+  print(fmt(tabf2, "Total Elements", figures("TOTAL_ALL")))
+  print(hl)
+  print(fmt(tabf2, "Total Tokens", figures("TOTAL_TOK")))
+  print(hl)
+  --------------------------------------------------------------------
+  -- report warning flags from optimizing process
+  --------------------------------------------------------------------
+  if optlex.warn.lstring then
+    print("* WARNING: "..optlex.warn.lstring)
+  elseif optlex.warn.mixedeol then
+    print("* WARNING: ".."output still contains some CRLF or LFCR line endings")
+  end
+  print()
+end
+
+--[[--------------------------------------------------------------------
+-- main functions
+----------------------------------------------------------------------]]
+
+local arg = {...}  -- program arguments
+local fspec = {}
+set_options(DEFAULT_CONFIG)     -- set to default options at beginning
+
+------------------------------------------------------------------------
+-- per-file handling, ship off to tasks
+------------------------------------------------------------------------
+
+local function do_files(fspec)
+  for _, srcfl in ipairs(fspec) do
+    local destfl
+    ------------------------------------------------------------------
+    -- find and replace extension for filenames
+    ------------------------------------------------------------------
+    local extb, exte = string.find(srcfl, "%.[^%.%\\%/]*$")
+    local basename, extension = srcfl, ""
+    if extb and extb > 1 then
+      basename = sub(srcfl, 1, extb - 1)
+      extension = sub(srcfl, extb, exte)
+    end
+    destfl = basename..suffix..extension
+    if #fspec == 1 and option.OUTPUT_FILE then
+      destfl = option.OUTPUT_FILE
+    end
+    if srcfl == destfl then
+      die("output filename identical to input filename")
+    end
+    ------------------------------------------------------------------
+    -- perform requested operations
+    ------------------------------------------------------------------
+    if option.DUMP_LEXER then
+      dump_tokens(srcfl)
+    elseif option.DUMP_PARSER then
+      dump_parser(srcfl)
+    elseif option.READ_ONLY then
+      read_only(srcfl)
+    else
+      process_file(srcfl, destfl)
+    end
+  end--for
+end
+
+------------------------------------------------------------------------
+-- main function (entry point is after this definition)
+------------------------------------------------------------------------
+
+local function main()
+  local argn, i = #arg, 1
+  if argn == 0 then
+    option.HELP = true
+  end
+  --------------------------------------------------------------------
+  -- handle arguments
+  --------------------------------------------------------------------
+  while i <= argn do
+    local o, p = arg[i], arg[i + 1]
+    local dash = string.match(o, "^%-%-?")
+    if dash == "-" then                 -- single-dash options
+      if o == "-h" then
+        option.HELP = true; break
+      elseif o == "-v" then
+        option.VERSION = true; break
+      elseif o == "-s" then
+        if not p then die("-s option needs suffix specification") end
+        suffix = p
+        i = i + 1
+      elseif o == "-o" then
+        if not p then die("-o option needs a file name") end
+        option.OUTPUT_FILE = p
+        i = i + 1
+      elseif o == "-" then
+        break -- ignore rest of args
+      else
+        die("unrecognized option "..o)
+      end
+    elseif dash == "--" then            -- double-dash options
+      if o == "--help" then
+        option.HELP = true; break
+      elseif o == "--version" then
+        option.VERSION = true; break
+      elseif o == "--keep" then
+        if not p then die("--keep option needs a string to match for") end
+        option.KEEP = p
+        i = i + 1
+      elseif o == "--plugin" then
+        if not p then die("--plugin option needs a module name") end
+        if option.PLUGIN then die("only one plugin can be specified") end
+        option.PLUGIN = p
+        plugin = require(PLUGIN_SUFFIX..p)
+        i = i + 1
+      elseif o == "--quiet" then
+        option.QUIET = true
+      elseif o == "--read-only" then
+        option.READ_ONLY = true
+      elseif o == "--basic" then
+        set_options(BASIC_CONFIG)
+      elseif o == "--maximum" then
+        set_options(MAXIMUM_CONFIG)
+      elseif o == "--none" then
+        set_options(NONE_CONFIG)
+      elseif o == "--dump-lexer" then
+        option.DUMP_LEXER = true
+      elseif o == "--dump-parser" then
+        option.DUMP_PARSER = true
+      elseif o == "--details" then
+        option.DETAILS = true
+      elseif OPTION[o] then  -- lookup optimization options
+        set_options(o)
+      else
+        die("unrecognized option "..o)
+      end
+    else
+      fspec[#fspec + 1] = o             -- potential filename
+    end
+    i = i + 1
+  end--while
+  if option.HELP then
+    print(MSG_TITLE..MSG_USAGE); return true
+  elseif option.VERSION then
+    print(MSG_TITLE); return true
+  end
+  if #fspec > 0 then
+    if #fspec > 1 and option.OUTPUT_FILE then
+      die("with -o, only one source file can be specified")
+    end
+    do_files(fspec)
+    return true
+  else
+    die("nothing to do!")
+  end
+end
+
+-- entry point -> main() -> do_files()
+if not main() then
+  die("Please run with option -h or --help for usage information")
+end
+
+-- end of script
diff --git a/contrib/luasrcdiet/lua/llex.lua b/contrib/luasrcdiet/lua/llex.lua
new file mode 100644
index 000000000..a637f3048
--- /dev/null
+++ b/contrib/luasrcdiet/lua/llex.lua
@@ -0,0 +1,355 @@
+--[[--------------------------------------------------------------------
+
+  llex.lua: Lua 5.1 lexical analyzer in Lua
+  This file is part of LuaSrcDiet, based on Yueliang material.
+
+  Copyright (c) 2008 Kein-Hong Man <khman@users.sf.net>
+  The COPYRIGHT file describes the conditions
+  under which this software may be distributed.
+
+  See the ChangeLog for more information.
+
+----------------------------------------------------------------------]]
+
+--[[--------------------------------------------------------------------
+-- NOTES:
+-- * This is a version of the native 5.1.x lexer from Yueliang 0.4.0,
+--   with significant modifications to handle LuaSrcDiet's needs:
+--   (1) llex.error is an optional error function handler
+--   (2) seminfo for strings include their delimiters and no
+--       translation operations are performed on them
+-- * ADDED shbang handling has been added to support executable scripts
+-- * NO localized decimal point replacement magic
+-- * NO limit to number of lines
+-- * NO support for compatible long strings (LUA_COMPAT_LSTR)
+-- * Please read technotes.txt for more technical details.
+----------------------------------------------------------------------]]
+
+local base = _G
+local string = require "string"
+module "llex"
+
+local find = string.find
+local match = string.match
+local sub = string.sub
+
+----------------------------------------------------------------------
+-- initialize keyword list, variables
+----------------------------------------------------------------------
+
+local kw = {}
+for v in string.gmatch([[
+and break do else elseif end false for function if in
+local nil not or repeat return then true until while]], "%S+") do
+  kw[v] = true
+end
+
+-- NOTE: see init() for module variables (externally visible):
+--       tok, seminfo, tokln
+
+local z,                -- source stream
+      sourceid,         -- name of source
+      I,                -- position of lexer
+      buff,             -- buffer for strings
+      ln                -- line number
+
+----------------------------------------------------------------------
+-- add information to token listing
+----------------------------------------------------------------------
+
+local function addtoken(token, info)
+  local i = #tok + 1
+  tok[i] = token
+  seminfo[i] = info
+  tokln[i] = ln
+end
+
+----------------------------------------------------------------------
+-- handles line number incrementation and end-of-line characters
+----------------------------------------------------------------------
+
+local function inclinenumber(i, is_tok)
+  local sub = sub
+  local old = sub(z, i, i)
+  i = i + 1  -- skip '\n' or '\r'
+  local c = sub(z, i, i)
+  if (c == "\n" or c == "\r") and (c ~= old) then
+    i = i + 1  -- skip '\n\r' or '\r\n'
+    old = old..c
+  end
+  if is_tok then addtoken("TK_EOL", old) end
+  ln = ln + 1
+  I = i
+  return i
+end
+
+----------------------------------------------------------------------
+-- initialize lexer for given source _z and source name _sourceid
+----------------------------------------------------------------------
+
+function init(_z, _sourceid)
+  z = _z                        -- source
+  sourceid = _sourceid          -- name of source
+  I = 1                         -- lexer's position in source
+  ln = 1                        -- line number
+  tok = {}                      -- lexed token list*
+  seminfo = {}                  -- lexed semantic information list*
+  tokln = {}                    -- line numbers for messages*
+                                -- (*) externally visible thru' module
+  --------------------------------------------------------------------
+  -- initial processing (shbang handling)
+  --------------------------------------------------------------------
+  local p, _, q, r = find(z, "^(#[^\r\n]*)(\r?\n?)")
+  if p then                             -- skip first line
+    I = I + #q
+    addtoken("TK_COMMENT", q)
+    if #r > 0 then inclinenumber(I, true) end
+  end
+end
+
+----------------------------------------------------------------------
+-- returns a chunk name or id, no truncation for long names
+----------------------------------------------------------------------
+
+function chunkid()
+  if sourceid and match(sourceid, "^[=@]") then
+    return sub(sourceid, 2)  -- remove first char
+  end
+  return "[string]"
+end
+
+----------------------------------------------------------------------
+-- formats error message and throws error
+-- * a simplified version, does not report what token was responsible
+----------------------------------------------------------------------
+
+function errorline(s, line)
+  local e = error or base.error
+  e(string.format("%s:%d: %s", chunkid(), line or ln, s))
+end
+local errorline = errorline
+
+------------------------------------------------------------------------
+-- count separators ("=") in a long string delimiter
+------------------------------------------------------------------------
+
+local function skip_sep(i)
+  local sub = sub
+  local s = sub(z, i, i)
+  i = i + 1
+  local count = #match(z, "=*", i)  -- note, take the length
+  i = i + count
+  I = i
+  return (sub(z, i, i) == s) and count or (-count) - 1
+end
+
+----------------------------------------------------------------------
+-- reads a long string or long comment
+----------------------------------------------------------------------
+
+local function read_long_string(is_str, sep)
+  local i = I + 1  -- skip 2nd '['
+  local sub = sub
+  local c = sub(z, i, i)
+  if c == "\r" or c == "\n" then  -- string starts with a newline?
+    i = inclinenumber(i)  -- skip it
+  end
+  local j = i
+  while true do
+    local p, q, r = find(z, "([\r\n%]])", i) -- (long range)
+    if not p then
+      errorline(is_str and "unfinished long string" or
+                "unfinished long comment")
+    end
+    i = p
+    if r == "]" then                    -- delimiter test
+      if skip_sep(i) == sep then
+        buff = sub(z, buff, I)
+        I = I + 1  -- skip 2nd ']'
+        return buff
+      end
+      i = I
+    else                                -- newline
+      buff = buff.."\n"
+      i = inclinenumber(i)
+    end
+  end--while
+end
+
+----------------------------------------------------------------------
+-- reads a string
+----------------------------------------------------------------------
+
+local function read_string(del)
+  local i = I
+  local find = find
+  local sub = sub
+  while true do
+    local p, q, r = find(z, "([\n\r\\\"\'])", i) -- (long range)
+    if p then
+      if r == "\n" or r == "\r" then
+        errorline("unfinished string")
+      end
+      i = p
+      if r == "\\" then                         -- handle escapes
+        i = i + 1
+        r = sub(z, i, i)
+        if r == "" then break end -- (EOZ error)
+        p = find("abfnrtv\n\r", r, 1, true)
+        ------------------------------------------------------
+        if p then                               -- special escapes
+          if p > 7 then
+            i = inclinenumber(i)
+          else
+            i = i + 1
+          end
+        ------------------------------------------------------
+        elseif find(r, "%D") then               -- other non-digits
+          i = i + 1
+        ------------------------------------------------------
+        else                                    -- \xxx sequence
+          local p, q, s = find(z, "^(%d%d?%d?)", i)
+          i = q + 1
+          if s + 1 > 256 then -- UCHAR_MAX
+            errorline("escape sequence too large")
+          end
+        ------------------------------------------------------
+        end--if p
+      else
+        i = i + 1
+        if r == del then                        -- ending delimiter
+          I = i
+          return sub(z, buff, i - 1)            -- return string
+        end
+      end--if r
+    else
+      break -- (error)
+    end--if p
+  end--while
+  errorline("unfinished string")
+end
+
+------------------------------------------------------------------------
+-- main lexer function
+------------------------------------------------------------------------
+
+function llex()
+  local find = find
+  local match = match
+  while true do--outer
+    local i = I
+    -- inner loop allows break to be used to nicely section tests
+    while true do--inner
+      ----------------------------------------------------------------
+      local p, _, r = find(z, "^([_%a][_%w]*)", i)
+      if p then
+        I = i + #r
+        if kw[r] then
+          addtoken("TK_KEYWORD", r)             -- reserved word (keyword)
+        else
+          addtoken("TK_NAME", r)                -- identifier
+        end
+        break -- (continue)
+      end
+      ----------------------------------------------------------------
+      local p, _, r = find(z, "^(%.?)%d", i)
+      if p then                                 -- numeral
+        if r == "." then i = i + 1 end
+        local _, q, r = find(z, "^%d*[%.%d]*([eE]?)", i)
+        i = q + 1
+        if #r == 1 then                         -- optional exponent
+          if match(z, "^[%+%-]", i) then        -- optional sign
+            i = i + 1
+          end
+        end
+        local _, q = find(z, "^[_%w]*", i)
+        I = q + 1
+        local v = sub(z, p, q)                  -- string equivalent
+        if not base.tonumber(v) then            -- handles hex test also
+          errorline("malformed number")
+        end
+        addtoken("TK_NUMBER", v)
+        break -- (continue)
+      end
+      ----------------------------------------------------------------
+      local p, q, r, t = find(z, "^((%s)[ \t\v\f]*)", i)
+      if p then
+        if t == "\n" or t == "\r" then          -- newline
+          inclinenumber(i, true)
+        else
+          I = q + 1                             -- whitespace
+          addtoken("TK_SPACE", r)
+        end
+        break -- (continue)
+      end
+      ----------------------------------------------------------------
+      local r = match(z, "^%p", i)
+      if r then
+        buff = i
+        local p = find("-[\"\'.=<>~", r, 1, true)
+        if p then
+          -- two-level if block for punctuation/symbols
+          --------------------------------------------------------
+          if p <= 2 then
+            if p == 1 then                      -- minus
+              local c = match(z, "^%-%-(%[?)", i)
+              if c then
+                i = i + 2
+                local sep = -1
+                if c == "[" then
+                  sep = skip_sep(i)
+                end
+                if sep >= 0 then                -- long comment
+                  addtoken("TK_LCOMMENT", read_long_string(false, sep))
+                else                            -- short comment
+                  I = find(z, "[\n\r]", i) or (#z + 1)
+                  addtoken("TK_COMMENT", sub(z, buff, I - 1))
+                end
+                break -- (continue)
+              end
+              -- (fall through for "-")
+            else                                -- [ or long string
+              local sep = skip_sep(i)
+              if sep >= 0 then
+                addtoken("TK_LSTRING", read_long_string(true, sep))
+              elseif sep == -1 then
+                addtoken("TK_OP", "[")
+              else
+                errorline("invalid long string delimiter")
+              end
+              break -- (continue)
+            end
+          --------------------------------------------------------
+          elseif p <= 5 then
+            if p < 5 then                       -- strings
+              I = i + 1
+              addtoken("TK_STRING", read_string(r))
+              break -- (continue)
+            end
+            r = match(z, "^%.%.?%.?", i)        -- .|..|... dots
+            -- (fall through)
+          --------------------------------------------------------
+          else                                  -- relational
+            r = match(z, "^%p=?", i)
+            -- (fall through)
+          end
+        end
+        I = i + #r
+        addtoken("TK_OP", r)  -- for other symbols, fall through
+        break -- (continue)
+      end
+      ----------------------------------------------------------------
+      local r = sub(z, i, i)
+      if r ~= "" then
+        I = i + 1
+        addtoken("TK_OP", r)                    -- other single-char tokens
+        break
+      end
+      addtoken("TK_EOS", "")                    -- end of stream,
+      return                                    -- exit here
+      ----------------------------------------------------------------
+    end--while inner
+  end--while outer
+end
+
+return base.getfenv()
diff --git a/contrib/luasrcdiet/lua/lparser.lua b/contrib/luasrcdiet/lua/lparser.lua
new file mode 100644
index 000000000..a1e10e016
--- /dev/null
+++ b/contrib/luasrcdiet/lua/lparser.lua
@@ -0,0 +1,1295 @@
+--[[--------------------------------------------------------------------
+
+  lparser.lua: Lua 5.1 parser in Lua
+  This file is part of LuaSrcDiet, based on Yueliang material.
+
+  Copyright (c) 2008 Kein-Hong Man <khman@users.sf.net>
+  The COPYRIGHT file describes the conditions
+  under which this software may be distributed.
+
+  See the ChangeLog for more information.
+
+----------------------------------------------------------------------]]
+
+--[[--------------------------------------------------------------------
+-- NOTES:
+-- * This is a version of the native 5.1.x parser from Yueliang 0.4.0,
+--   with significant modifications to handle LuaSrcDiet's needs:
+--   (1) needs pre-built token tables instead of a module.method
+--   (2) lparser.error is an optional error handler (from llex)
+--   (3) not full parsing, currently fakes raw/unlexed constants
+--   (4) parser() returns globalinfo, localinfo tables
+-- * Please read technotes.txt for more technical details.
+-- * NO support for 'arg' vararg functions (LUA_COMPAT_VARARG)
+-- * A lot of the parser is unused, but might later be useful for
+--   full-on parsing and analysis for a few measly bytes saved.
+----------------------------------------------------------------------]]
+
+local base = _G
+local string = require "string"
+module "lparser"
+local _G = base.getfenv()
+
+--[[--------------------------------------------------------------------
+-- variable and data structure initialization
+----------------------------------------------------------------------]]
+
+----------------------------------------------------------------------
+-- initialization: main variables
+----------------------------------------------------------------------
+
+local toklist,                  -- grammar-only token tables (token table,
+      seminfolist,              -- semantic information table, line number
+      toklnlist,                -- table, cross-reference table)
+      xreflist,
+      tpos,                     -- token position
+
+      line,                     -- start line # for error messages
+      lastln,                   -- last line # for ambiguous syntax chk
+      tok, seminfo, ln, xref,   -- token, semantic info, line
+      nameref,                  -- proper position of <name> token
+      fs,                       -- current function state
+      top_fs,                   -- top-level function state
+
+      globalinfo,               -- global variable information table
+      globallookup,             -- global variable name lookup table
+      localinfo,                -- local variable information table
+      ilocalinfo,               -- inactive locals (prior to activation)
+      ilocalrefs                -- corresponding references to activate
+
+-- forward references for local functions
+local explist1, expr, block, exp1, body, chunk
+
+----------------------------------------------------------------------
+-- initialization: data structures
+----------------------------------------------------------------------
+
+local gmatch = string.gmatch
+
+local block_follow = {}         -- lookahead check in chunk(), returnstat()
+for v in gmatch("else elseif end until <eof>", "%S+") do
+  block_follow[v] = true
+end
+
+local stat_call = {}            -- lookup for calls in stat()
+for v in gmatch("if while do for repeat function local return break", "%S+") do
+  stat_call[v] = v.."_stat"
+end
+
+local binopr_left = {}          -- binary operators, left priority
+local binopr_right = {}         -- binary operators, right priority
+for op, lt, rt in gmatch([[
+{+ 6 6}{- 6 6}{* 7 7}{/ 7 7}{% 7 7}
+{^ 10 9}{.. 5 4}
+{~= 3 3}{== 3 3}
+{< 3 3}{<= 3 3}{> 3 3}{>= 3 3}
+{and 2 2}{or 1 1}
+]], "{(%S+)%s(%d+)%s(%d+)}") do
+  binopr_left[op] = lt + 0
+  binopr_right[op] = rt + 0
+end
+
+local unopr = { ["not"] = true, ["-"] = true,
+                ["#"] = true, } -- unary operators
+local UNARY_PRIORITY = 8        -- priority for unary operators
+
+--[[--------------------------------------------------------------------
+-- support functions
+----------------------------------------------------------------------]]
+
+----------------------------------------------------------------------
+-- formats error message and throws error (duplicated from llex)
+-- * a simplified version, does not report what token was responsible
+----------------------------------------------------------------------
+
+local function errorline(s, line)
+  local e = error or base.error
+  e(string.format("(source):%d: %s", line or ln, s))
+end
+
+----------------------------------------------------------------------
+-- handles incoming token, semantic information pairs
+-- * NOTE: 'nextt' is named 'next' originally
+----------------------------------------------------------------------
+
+-- reads in next token
+local function nextt()
+  lastln = toklnlist[tpos]
+  tok, seminfo, ln, xref
+    = toklist[tpos], seminfolist[tpos], toklnlist[tpos], xreflist[tpos]
+  tpos = tpos + 1
+end
+
+-- peek at next token (single lookahead for table constructor)
+local function lookahead()
+  return toklist[tpos]
+end
+
+----------------------------------------------------------------------
+-- throws a syntax error, or if token expected is not there
+----------------------------------------------------------------------
+
+local function syntaxerror(msg)
+  local tok = tok
+  if tok ~= "<number>" and tok ~= "<string>" then
+    if tok == "<name>" then tok = seminfo end
+    tok = "'"..tok.."'"
+  end
+  errorline(msg.." near "..tok)
+end
+
+local function error_expected(token)
+  syntaxerror("'"..token.."' expected")
+end
+
+----------------------------------------------------------------------
+-- tests for a token, returns outcome
+-- * return value changed to boolean
+----------------------------------------------------------------------
+
+local function testnext(c)
+  if tok == c then nextt(); return true end
+end
+
+----------------------------------------------------------------------
+-- check for existence of a token, throws error if not found
+----------------------------------------------------------------------
+
+local function check(c)
+  if tok ~= c then error_expected(c) end
+end
+
+----------------------------------------------------------------------
+-- verify existence of a token, then skip it
+----------------------------------------------------------------------
+
+local function checknext(c)
+  check(c); nextt()
+end
+
+----------------------------------------------------------------------
+-- throws error if condition not matched
+----------------------------------------------------------------------
+
+local function check_condition(c, msg)
+  if not c then syntaxerror(msg) end
+end
+
+----------------------------------------------------------------------
+-- verifies token conditions are met or else throw error
+----------------------------------------------------------------------
+
+local function check_match(what, who, where)
+  if not testnext(what) then
+    if where == ln then
+      error_expected(what)
+    else
+      syntaxerror("'"..what.."' expected (to close '"..who.."' at line "..where..")")
+    end
+  end
+end
+
+----------------------------------------------------------------------
+-- expect that token is a name, return the name
+----------------------------------------------------------------------
+
+local function str_checkname()
+  check("<name>")
+  local ts = seminfo
+  nameref = xref
+  nextt()
+  return ts
+end
+
+----------------------------------------------------------------------
+-- adds given string s in string pool, sets e as VK
+----------------------------------------------------------------------
+
+local function codestring(e, s)
+  e.k = "VK"
+end
+
+----------------------------------------------------------------------
+-- consume a name token, adds it to string pool
+----------------------------------------------------------------------
+
+local function checkname(e)
+  codestring(e, str_checkname())
+end
+
+--[[--------------------------------------------------------------------
+-- variable (global|local|upvalue) handling
+-- * to track locals and globals, we can extend Yueliang's minimal
+--   variable management code with little trouble
+-- * entry point is singlevar() for variable lookups
+-- * lookup tables (bl.locallist) are maintained awkwardly in the basic
+--   block data structures, PLUS the function data structure (this is
+--   an inelegant hack, since bl is nil for the top level of a function)
+----------------------------------------------------------------------]]
+
+----------------------------------------------------------------------
+-- register a local variable, create local variable object, set in
+-- to-activate variable list
+-- * used in new_localvarliteral(), parlist(), fornum(), forlist(),
+--   localfunc(), localstat()
+----------------------------------------------------------------------
+
+local function new_localvar(name, special)
+  local bl = fs.bl
+  local locallist
+  -- locate locallist in current block object or function root object
+  if bl then
+    locallist = bl.locallist
+  else
+    locallist = fs.locallist
+  end
+  -- build local variable information object and set localinfo
+  local id = #localinfo + 1
+  localinfo[id] = {             -- new local variable object
+    name = name,                -- local variable name
+    xref = { nameref },         -- xref, first value is declaration
+    decl = nameref,             -- location of declaration, = xref[1]
+  }
+  if special then               -- "self" must be not be changed
+    localinfo[id].isself = true
+  end
+  -- this can override a local with the same name in the same scope
+  -- but first, keep it inactive until it gets activated
+  local i = #ilocalinfo + 1
+  ilocalinfo[i] = id
+  ilocalrefs[i] = locallist
+end
+
+----------------------------------------------------------------------
+-- actually activate the variables so that they are visible
+-- * remember Lua semantics, e.g. RHS is evaluated first, then LHS
+-- * used in parlist(), forbody(), localfunc(), localstat(), body()
+----------------------------------------------------------------------
+
+local function adjustlocalvars(nvars)
+  local sz = #ilocalinfo
+  -- i goes from left to right, in order of local allocation, because
+  -- of something like: local a,a,a = 1,2,3 which gives a = 3
+  while nvars > 0 do
+    nvars = nvars - 1
+    local i = sz - nvars
+    local id = ilocalinfo[i]            -- local's id
+    local obj = localinfo[id]
+    local name = obj.name               -- name of local
+    obj.act = xref                      -- set activation location
+    ilocalinfo[i] = nil
+    local locallist = ilocalrefs[i]     -- ref to lookup table to update
+    ilocalrefs[i] = nil
+    local existing = locallist[name]    -- if existing, remove old first!
+    if existing then                    -- do not overlap, set special
+      obj = localinfo[existing]         -- form of rem, as -id
+      obj.rem = -id
+    end
+    locallist[name] = id                -- activate, now visible to Lua
+  end
+end
+
+----------------------------------------------------------------------
+-- remove (deactivate) variables in current scope (before scope exits)
+-- * zap entire locallist tables since we are not allocating registers
+-- * used in leaveblock(), close_func()
+----------------------------------------------------------------------
+
+local function removevars()
+  local bl = fs.bl
+  local locallist
+  -- locate locallist in current block object or function root object
+  if bl then
+    locallist = bl.locallist
+  else
+    locallist = fs.locallist
+  end
+  -- enumerate the local list at current scope and deactivate 'em
+  for name, id in base.pairs(locallist) do
+    local obj = localinfo[id]
+    obj.rem = xref                      -- set deactivation location
+  end
+end
+
+----------------------------------------------------------------------
+-- creates a new local variable given a name
+-- * skips internal locals (those starting with '('), so internal
+--   locals never needs a corresponding adjustlocalvars() call
+-- * special is true for "self" which must not be optimized
+-- * used in fornum(), forlist(), parlist(), body()
+----------------------------------------------------------------------
+
+local function new_localvarliteral(name, special)
+  if string.sub(name, 1, 1) == "(" then  -- can skip internal locals
+    return
+  end
+  new_localvar(name, special)
+end
+
+----------------------------------------------------------------------
+-- search the local variable namespace of the given fs for a match
+-- * returns localinfo index
+-- * used only in singlevaraux()
+----------------------------------------------------------------------
+
+local function searchvar(fs, n)
+  local bl = fs.bl
+  local locallist
+  if bl then
+    locallist = bl.locallist
+    while locallist do
+      if locallist[n] then return locallist[n] end  -- found
+      bl = bl.prev
+      locallist = bl and bl.locallist
+    end
+  end
+  locallist = fs.locallist
+  return locallist[n] or -1  -- found or not found (-1)
+end
+
+----------------------------------------------------------------------
+-- handle locals, globals and upvalues and related processing
+-- * search mechanism is recursive, calls itself to search parents
+-- * used only in singlevar()
+----------------------------------------------------------------------
+
+local function singlevaraux(fs, n, var)
+  if fs == nil then  -- no more levels?
+    var.k = "VGLOBAL"  -- default is global variable
+    return "VGLOBAL"
+  else
+    local v = searchvar(fs, n)  -- look up at current level
+    if v >= 0 then
+      var.k = "VLOCAL"
+      var.id = v
+      --  codegen may need to deal with upvalue here
+      return "VLOCAL"
+    else  -- not found at current level; try upper one
+      if singlevaraux(fs.prev, n, var) == "VGLOBAL" then
+        return "VGLOBAL"
+      end
+      -- else was LOCAL or UPVAL, handle here
+      var.k = "VUPVAL"  -- upvalue in this level
+      return "VUPVAL"
+    end--if v
+  end--if fs
+end
+
+----------------------------------------------------------------------
+-- consume a name token, creates a variable (global|local|upvalue)
+-- * used in prefixexp(), funcname()
+----------------------------------------------------------------------
+
+local function singlevar(v)
+  local name = str_checkname()
+  singlevaraux(fs, name, v)
+  ------------------------------------------------------------------
+  -- variable tracking
+  ------------------------------------------------------------------
+  if v.k == "VGLOBAL" then
+    -- if global being accessed, keep track of it by creating an object
+    local id = globallookup[name]
+    if not id then
+      id = #globalinfo + 1
+      globalinfo[id] = {                -- new global variable object
+        name = name,                    -- global variable name
+        xref = { nameref },             -- xref, first value is declaration
+      }
+      globallookup[name] = id           -- remember it
+    else
+      local obj = globalinfo[id].xref
+      obj[#obj + 1] = nameref           -- add xref
+    end
+  else
+    -- local/upvalue is being accessed, keep track of it
+    local id = v.id
+    local obj = localinfo[id].xref
+    obj[#obj + 1] = nameref             -- add xref
+  end
+end
+
+--[[--------------------------------------------------------------------
+-- state management functions with open/close pairs
+----------------------------------------------------------------------]]
+
+----------------------------------------------------------------------
+-- enters a code unit, initializes elements
+----------------------------------------------------------------------
+
+local function enterblock(isbreakable)
+  local bl = {}  -- per-block state
+  bl.isbreakable = isbreakable
+  bl.prev = fs.bl
+  bl.locallist = {}
+  fs.bl = bl
+end
+
+----------------------------------------------------------------------
+-- leaves a code unit, close any upvalues
+----------------------------------------------------------------------
+
+local function leaveblock()
+  local bl = fs.bl
+  removevars()
+  fs.bl = bl.prev
+end
+
+----------------------------------------------------------------------
+-- opening of a function
+-- * top_fs is only for anchoring the top fs, so that parser() can
+--   return it to the caller function along with useful output
+-- * used in parser() and body()
+----------------------------------------------------------------------
+
+local function open_func()
+  local new_fs  -- per-function state
+  if not fs then  -- top_fs is created early
+    new_fs = top_fs
+  else
+    new_fs = {}
+  end
+  new_fs.prev = fs  -- linked list of function states
+  new_fs.bl = nil
+  new_fs.locallist = {}
+  fs = new_fs
+end
+
+----------------------------------------------------------------------
+-- closing of a function
+-- * used in parser() and body()
+----------------------------------------------------------------------
+
+local function close_func()
+  removevars()
+  fs = fs.prev
+end
+
+--[[--------------------------------------------------------------------
+-- other parsing functions
+-- * for table constructor, parameter list, argument list
+----------------------------------------------------------------------]]
+
+----------------------------------------------------------------------
+-- parse a function name suffix, for function call specifications
+-- * used in primaryexp(), funcname()
+----------------------------------------------------------------------
+
+local function field(v)
+  -- field -> ['.' | ':'] NAME
+  local key = {}
+  nextt()  -- skip the dot or colon
+  checkname(key)
+  v.k = "VINDEXED"
+end
+
+----------------------------------------------------------------------
+-- parse a table indexing suffix, for constructors, expressions
+-- * used in recfield(), primaryexp()
+----------------------------------------------------------------------
+
+local function yindex(v)
+  -- index -> '[' expr ']'
+  nextt()  -- skip the '['
+  expr(v)
+  checknext("]")
+end
+
+----------------------------------------------------------------------
+-- parse a table record (hash) field
+-- * used in constructor()
+----------------------------------------------------------------------
+
+local function recfield(cc)
+  -- recfield -> (NAME | '['exp1']') = exp1
+  local key, val = {}, {}
+  if tok == "<name>" then
+    checkname(key)
+  else-- tok == '['
+    yindex(key)
+  end
+  checknext("=")
+  expr(val)
+end
+
+----------------------------------------------------------------------
+-- emit a set list instruction if enough elements (LFIELDS_PER_FLUSH)
+-- * note: retained in this skeleton because it modifies cc.v.k
+-- * used in constructor()
+----------------------------------------------------------------------
+
+local function closelistfield(cc)
+  if cc.v.k == "VVOID" then return end  -- there is no list item
+  cc.v.k = "VVOID"
+end
+
+----------------------------------------------------------------------
+-- parse a table list (array) field
+-- * used in constructor()
+----------------------------------------------------------------------
+
+local function listfield(cc)
+  expr(cc.v)
+end
+
+----------------------------------------------------------------------
+-- parse a table constructor
+-- * used in funcargs(), simpleexp()
+----------------------------------------------------------------------
+
+local function constructor(t)
+  -- constructor -> '{' [ field { fieldsep field } [ fieldsep ] ] '}'
+  -- field -> recfield | listfield
+  -- fieldsep -> ',' | ';'
+  local line = ln
+  local cc = {}
+  cc.v = {}
+  cc.t = t
+  t.k = "VRELOCABLE"
+  cc.v.k = "VVOID"
+  checknext("{")
+  repeat
+    if tok == "}" then break end
+    -- closelistfield(cc) here
+    local c = tok
+    if c == "<name>" then  -- may be listfields or recfields
+      if lookahead() ~= "=" then  -- look ahead: expression?
+        listfield(cc)
+      else
+        recfield(cc)
+      end
+    elseif c == "[" then  -- constructor_item -> recfield
+      recfield(cc)
+    else  -- constructor_part -> listfield
+      listfield(cc)
+    end
+  until not testnext(",") and not testnext(";")
+  check_match("}", "{", line)
+  -- lastlistfield(cc) here
+end
+
+----------------------------------------------------------------------
+-- parse the arguments (parameters) of a function declaration
+-- * used in body()
+----------------------------------------------------------------------
+
+local function parlist()
+  -- parlist -> [ param { ',' param } ]
+  local nparams = 0
+  if tok ~= ")" then  -- is 'parlist' not empty?
+    repeat
+      local c = tok
+      if c == "<name>" then  -- param -> NAME
+        new_localvar(str_checkname())
+        nparams = nparams + 1
+      elseif c == "..." then
+        nextt()
+        fs.is_vararg = true
+      else
+        syntaxerror("<name> or '...' expected")
+      end
+    until fs.is_vararg or not testnext(",")
+  end--if
+  adjustlocalvars(nparams)
+end
+
+----------------------------------------------------------------------
+-- parse the parameters of a function call
+-- * contrast with parlist(), used in function declarations
+-- * used in primaryexp()
+----------------------------------------------------------------------
+
+local function funcargs(f)
+  local args = {}
+  local line = ln
+  local c = tok
+  if c == "(" then  -- funcargs -> '(' [ explist1 ] ')'
+    if line ~= lastln then
+      syntaxerror("ambiguous syntax (function call x new statement)")
+    end
+    nextt()
+    if tok == ")" then  -- arg list is empty?
+      args.k = "VVOID"
+    else
+      explist1(args)
+    end
+    check_match(")", "(", line)
+  elseif c == "{" then  -- funcargs -> constructor
+    constructor(args)
+  elseif c == "<string>" then  -- funcargs -> STRING
+    codestring(args, seminfo)
+    nextt()  -- must use 'seminfo' before 'next'
+  else
+    syntaxerror("function arguments expected")
+    return
+  end--if c
+  f.k = "VCALL"
+end
+
+--[[--------------------------------------------------------------------
+-- mostly expression functions
+----------------------------------------------------------------------]]
+
+----------------------------------------------------------------------
+-- parses an expression in parentheses or a single variable
+-- * used in primaryexp()
+----------------------------------------------------------------------
+
+local function prefixexp(v)
+  -- prefixexp -> NAME | '(' expr ')'
+  local c = tok
+  if c == "(" then
+    local line = ln
+    nextt()
+    expr(v)
+    check_match(")", "(", line)
+  elseif c == "<name>" then
+    singlevar(v)
+  else
+    syntaxerror("unexpected symbol")
+  end--if c
+end
+
+----------------------------------------------------------------------
+-- parses a prefixexp (an expression in parentheses or a single
+-- variable) or a function call specification
+-- * used in simpleexp(), assignment(), expr_stat()
+----------------------------------------------------------------------
+
+local function primaryexp(v)
+  -- primaryexp ->
+  --    prefixexp { '.' NAME | '[' exp ']' | ':' NAME funcargs | funcargs }
+  prefixexp(v)
+  while true do
+    local c = tok
+    if c == "." then  -- field
+      field(v)
+    elseif c == "[" then  -- '[' exp1 ']'
+      local key = {}
+      yindex(key)
+    elseif c == ":" then  -- ':' NAME funcargs
+      local key = {}
+      nextt()
+      checkname(key)
+      funcargs(v)
+    elseif c == "(" or c == "<string>" or c == "{" then  -- funcargs
+      funcargs(v)
+    else
+      return
+    end--if c
+  end--while
+end
+
+----------------------------------------------------------------------
+-- parses general expression types, constants handled here
+-- * used in subexpr()
+----------------------------------------------------------------------
+
+local function simpleexp(v)
+  -- simpleexp -> NUMBER | STRING | NIL | TRUE | FALSE | ... |
+  --              constructor | FUNCTION body | primaryexp
+  local c = tok
+  if c == "<number>" then
+    v.k = "VKNUM"
+  elseif c == "<string>" then
+    codestring(v, seminfo)
+  elseif c == "nil" then
+    v.k = "VNIL"
+  elseif c == "true" then
+    v.k = "VTRUE"
+  elseif c == "false" then
+    v.k = "VFALSE"
+  elseif c == "..." then  -- vararg
+    check_condition(fs.is_vararg == true,
+                    "cannot use '...' outside a vararg function");
+    v.k = "VVARARG"
+  elseif c == "{" then  -- constructor
+    constructor(v)
+    return
+  elseif c == "function" then
+    nextt()
+    body(v, false, ln)
+    return
+  else
+    primaryexp(v)
+    return
+  end--if c
+  nextt()
+end
+
+------------------------------------------------------------------------
+-- Parse subexpressions. Includes handling of unary operators and binary
+-- operators. A subexpr is given the rhs priority level of the operator
+-- immediately left of it, if any (limit is -1 if none,) and if a binop
+-- is found, limit is compared with the lhs priority level of the binop
+-- in order to determine which executes first.
+-- * recursively called
+-- * used in expr()
+------------------------------------------------------------------------
+
+local function subexpr(v, limit)
+  -- subexpr -> (simpleexp | unop subexpr) { binop subexpr }
+  --   * where 'binop' is any binary operator with a priority
+  --     higher than 'limit'
+  local op = tok
+  local uop = unopr[op]
+  if uop then
+    nextt()
+    subexpr(v, UNARY_PRIORITY)
+  else
+    simpleexp(v)
+  end
+  -- expand while operators have priorities higher than 'limit'
+  op = tok
+  local binop = binopr_left[op]
+  while binop and binop > limit do
+    local v2 = {}
+    nextt()
+    -- read sub-expression with higher priority
+    local nextop = subexpr(v2, binopr_right[op])
+    op = nextop
+    binop = binopr_left[op]
+  end
+  return op  -- return first untreated operator
+end
+
+----------------------------------------------------------------------
+-- Expression parsing starts here. Function subexpr is entered with the
+-- left operator (which is non-existent) priority of -1, which is lower
+-- than all actual operators. Expr information is returned in parm v.
+-- * used in cond(), explist1(), index(), recfield(), listfield(),
+--   prefixexp(), while_stat(), exp1()
+----------------------------------------------------------------------
+
+-- this is a forward-referenced local
+function expr(v)
+  -- expr -> subexpr
+  subexpr(v, 0)
+end
+
+--[[--------------------------------------------------------------------
+-- third level parsing functions
+----------------------------------------------------------------------]]
+
+------------------------------------------------------------------------
+-- parse a variable assignment sequence
+-- * recursively called
+-- * used in expr_stat()
+------------------------------------------------------------------------
+
+local function assignment(v)
+  local e = {}
+  local c = v.v.k
+  check_condition(c == "VLOCAL" or c == "VUPVAL" or c == "VGLOBAL"
+                  or c == "VINDEXED", "syntax error")
+  if testnext(",") then  -- assignment -> ',' primaryexp assignment
+    local nv = {}  -- expdesc
+    nv.v = {}
+    primaryexp(nv.v)
+    -- lparser.c deals with some register usage conflict here
+    assignment(nv)
+  else  -- assignment -> '=' explist1
+    checknext("=")
+    explist1(e)
+    return  -- avoid default
+  end
+  e.k = "VNONRELOC"
+end
+
+----------------------------------------------------------------------
+-- parse a for loop body for both versions of the for loop
+-- * used in fornum(), forlist()
+----------------------------------------------------------------------
+
+local function forbody(nvars, isnum)
+  -- forbody -> DO block
+  checknext("do")
+  enterblock(false)  -- scope for declared variables
+  adjustlocalvars(nvars)
+  block()
+  leaveblock()  -- end of scope for declared variables
+end
+
+----------------------------------------------------------------------
+-- parse a numerical for loop, calls forbody()
+-- * used in for_stat()
+----------------------------------------------------------------------
+
+local function fornum(varname)
+  -- fornum -> NAME = exp1, exp1 [, exp1] DO body
+  local line = line
+  new_localvarliteral("(for index)")
+  new_localvarliteral("(for limit)")
+  new_localvarliteral("(for step)")
+  new_localvar(varname)
+  checknext("=")
+  exp1()  -- initial value
+  checknext(",")
+  exp1()  -- limit
+  if testnext(",") then
+    exp1()  -- optional step
+  else
+    -- default step = 1
+  end
+  forbody(1, true)
+end
+
+----------------------------------------------------------------------
+-- parse a generic for loop, calls forbody()
+-- * used in for_stat()
+----------------------------------------------------------------------
+
+local function forlist(indexname)
+  -- forlist -> NAME {, NAME} IN explist1 DO body
+  local e = {}
+  -- create control variables
+  new_localvarliteral("(for generator)")
+  new_localvarliteral("(for state)")
+  new_localvarliteral("(for control)")
+  -- create declared variables
+  new_localvar(indexname)
+  local nvars = 1
+  while testnext(",") do
+    new_localvar(str_checkname())
+    nvars = nvars + 1
+  end
+  checknext("in")
+  local line = line
+  explist1(e)
+  forbody(nvars, false)
+end
+
+----------------------------------------------------------------------
+-- parse a function name specification
+-- * used in func_stat()
+----------------------------------------------------------------------
+
+local function funcname(v)
+  -- funcname -> NAME {field} [':' NAME]
+  local needself = false
+  singlevar(v)
+  while tok == "." do
+    field(v)
+  end
+  if tok == ":" then
+    needself = true
+    field(v)
+  end
+  return needself
+end
+
+----------------------------------------------------------------------
+-- parse the single expressions needed in numerical for loops
+-- * used in fornum()
+----------------------------------------------------------------------
+
+-- this is a forward-referenced local
+function exp1()
+  -- exp1 -> expr
+  local e = {}
+  expr(e)
+end
+
+----------------------------------------------------------------------
+-- parse condition in a repeat statement or an if control structure
+-- * used in repeat_stat(), test_then_block()
+----------------------------------------------------------------------
+
+local function cond()
+  -- cond -> expr
+  local v = {}
+  expr(v)  -- read condition
+end
+
+----------------------------------------------------------------------
+-- parse part of an if control structure, including the condition
+-- * used in if_stat()
+----------------------------------------------------------------------
+
+local function test_then_block()
+  -- test_then_block -> [IF | ELSEIF] cond THEN block
+  nextt()  -- skip IF or ELSEIF
+  cond()
+  checknext("then")
+  block()  -- 'then' part
+end
+
+----------------------------------------------------------------------
+-- parse a local function statement
+-- * used in local_stat()
+----------------------------------------------------------------------
+
+local function localfunc()
+  -- localfunc -> NAME body
+  local v, b = {}
+  new_localvar(str_checkname())
+  v.k = "VLOCAL"
+  adjustlocalvars(1)
+  body(b, false, ln)
+end
+
+----------------------------------------------------------------------
+-- parse a local variable declaration statement
+-- * used in local_stat()
+----------------------------------------------------------------------
+
+local function localstat()
+  -- localstat -> NAME {',' NAME} ['=' explist1]
+  local nvars = 0
+  local e = {}
+  repeat
+    new_localvar(str_checkname())
+    nvars = nvars + 1
+  until not testnext(",")
+  if testnext("=") then
+    explist1(e)
+  else
+    e.k = "VVOID"
+  end
+  adjustlocalvars(nvars)
+end
+
+----------------------------------------------------------------------
+-- parse a list of comma-separated expressions
+-- * used in return_stat(), localstat(), funcargs(), assignment(),
+--   forlist()
+----------------------------------------------------------------------
+
+-- this is a forward-referenced local
+function explist1(e)
+  -- explist1 -> expr { ',' expr }
+  expr(e)
+  while testnext(",") do
+    expr(e)
+  end
+end
+
+----------------------------------------------------------------------
+-- parse function declaration body
+-- * used in simpleexp(), localfunc(), func_stat()
+----------------------------------------------------------------------
+
+-- this is a forward-referenced local
+function body(e, needself, line)
+  -- body ->  '(' parlist ')' chunk END
+  open_func()
+  checknext("(")
+  if needself then
+    new_localvarliteral("self", true)
+    adjustlocalvars(1)
+  end
+  parlist()
+  checknext(")")
+  chunk()
+  check_match("end", "function", line)
+  close_func()
+end
+
+----------------------------------------------------------------------
+-- parse a code block or unit
+-- * used in do_stat(), while_stat(), forbody(), test_then_block(),
+--   if_stat()
+----------------------------------------------------------------------
+
+-- this is a forward-referenced local
+function block()
+  -- block -> chunk
+  enterblock(false)
+  chunk()
+  leaveblock()
+end
+
+--[[--------------------------------------------------------------------
+-- second level parsing functions, all with '_stat' suffix
+-- * since they are called via a table lookup, they cannot be local
+--   functions (a lookup table of local functions might be smaller...)
+-- * stat() -> *_stat()
+----------------------------------------------------------------------]]
+
+----------------------------------------------------------------------
+-- initial parsing for a for loop, calls fornum() or forlist()
+-- * removed 'line' parameter (used to set debug information only)
+-- * used in stat()
+----------------------------------------------------------------------
+
+function for_stat()
+  -- stat -> for_stat -> FOR (fornum | forlist) END
+  local line = line
+  enterblock(true)  -- scope for loop and control variables
+  nextt()  -- skip 'for'
+  local varname = str_checkname()  -- first variable name
+  local c = tok
+  if c == "=" then
+    fornum(varname)
+  elseif c == "," or c == "in" then
+    forlist(varname)
+  else
+    syntaxerror("'=' or 'in' expected")
+  end
+  check_match("end", "for", line)
+  leaveblock()  -- loop scope (`break' jumps to this point)
+end
+
+----------------------------------------------------------------------
+-- parse a while-do control structure, body processed by block()
+-- * used in stat()
+----------------------------------------------------------------------
+
+function while_stat()
+  -- stat -> while_stat -> WHILE cond DO block END
+  local line = line
+  nextt()  -- skip WHILE
+  cond()  -- parse condition
+  enterblock(true)
+  checknext("do")
+  block()
+  check_match("end", "while", line)
+  leaveblock()
+end
+
+----------------------------------------------------------------------
+-- parse a repeat-until control structure, body parsed by chunk()
+-- * originally, repeatstat() calls breakstat() too if there is an
+--   upvalue in the scope block; nothing is actually lexed, it is
+--   actually the common code in breakstat() for closing of upvalues
+-- * used in stat()
+----------------------------------------------------------------------
+
+function repeat_stat()
+  -- stat -> repeat_stat -> REPEAT block UNTIL cond
+  local line = line
+  enterblock(true)  -- loop block
+  enterblock(false)  -- scope block
+  nextt()  -- skip REPEAT
+  chunk()
+  check_match("until", "repeat", line)
+  cond()
+  -- close upvalues at scope level below
+  leaveblock()  -- finish scope
+  leaveblock()  -- finish loop
+end
+
+----------------------------------------------------------------------
+-- parse an if control structure
+-- * used in stat()
+----------------------------------------------------------------------
+
+function if_stat()
+  -- stat -> if_stat -> IF cond THEN block
+  --                    {ELSEIF cond THEN block} [ELSE block] END
+  local line = line
+  local v = {}
+  test_then_block()  -- IF cond THEN block
+  while tok == "elseif" do
+    test_then_block()  -- ELSEIF cond THEN block
+  end
+  if tok == "else" then
+    nextt()  -- skip ELSE
+    block()  -- 'else' part
+  end
+  check_match("end", "if", line)
+end
+
+----------------------------------------------------------------------
+-- parse a return statement
+-- * used in stat()
+----------------------------------------------------------------------
+
+function return_stat()
+  -- stat -> return_stat -> RETURN explist
+  local e = {}
+  nextt()  -- skip RETURN
+  local c = tok
+  if block_follow[c] or c == ";" then
+    -- return no values
+  else
+    explist1(e)  -- optional return values
+  end
+end
+
+----------------------------------------------------------------------
+-- parse a break statement
+-- * used in stat()
+----------------------------------------------------------------------
+
+function break_stat()
+  -- stat -> break_stat -> BREAK
+  local bl = fs.bl
+  nextt()  -- skip BREAK
+  while bl and not bl.isbreakable do -- find a breakable block
+    bl = bl.prev
+  end
+  if not bl then
+    syntaxerror("no loop to break")
+  end
+end
+
+----------------------------------------------------------------------
+-- parse a function call with no returns or an assignment statement
+-- * the struct with .prev is used for name searching in lparse.c,
+--   so it is retained for now; present in assignment() also
+-- * used in stat()
+----------------------------------------------------------------------
+
+function expr_stat()
+  -- stat -> expr_stat -> func | assignment
+  local v = {}
+  v.v = {}
+  primaryexp(v.v)
+  if v.v.k == "VCALL" then  -- stat -> func
+    -- call statement uses no results
+  else  -- stat -> assignment
+    v.prev = nil
+    assignment(v)
+  end
+end
+
+----------------------------------------------------------------------
+-- parse a function statement
+-- * used in stat()
+----------------------------------------------------------------------
+
+function function_stat()
+  -- stat -> function_stat -> FUNCTION funcname body
+  local line = line
+  local v, b = {}, {}
+  nextt()  -- skip FUNCTION
+  local needself = funcname(v)
+  body(b, needself, line)
+end
+
+----------------------------------------------------------------------
+-- parse a simple block enclosed by a DO..END pair
+-- * used in stat()
+----------------------------------------------------------------------
+
+function do_stat()
+  -- stat -> do_stat -> DO block END
+  local line = line
+  nextt()  -- skip DO
+  block()
+  check_match("end", "do", line)
+end
+
+----------------------------------------------------------------------
+-- parse a statement starting with LOCAL
+-- * used in stat()
+----------------------------------------------------------------------
+
+function local_stat()
+  -- stat -> local_stat -> LOCAL FUNCTION localfunc
+  --                    -> LOCAL localstat
+  nextt()  -- skip LOCAL
+  if testnext("function") then  -- local function?
+    localfunc()
+  else
+    localstat()
+  end
+end
+
+--[[--------------------------------------------------------------------
+-- main functions, top level parsing functions
+-- * accessible functions are: init(lexer), parser()
+-- * [entry] -> parser() -> chunk() -> stat()
+----------------------------------------------------------------------]]
+
+----------------------------------------------------------------------
+-- initial parsing for statements, calls '_stat' suffixed functions
+-- * used in chunk()
+----------------------------------------------------------------------
+
+local function stat()
+  -- stat -> if_stat while_stat do_stat for_stat repeat_stat
+  --         function_stat local_stat return_stat break_stat
+  --         expr_stat
+  line = ln  -- may be needed for error messages
+  local c = tok
+  local fn = stat_call[c]
+  -- handles: if while do for repeat function local return break
+  if fn then
+    _G[fn]()
+    -- return or break must be last statement
+    if c == "return" or c == "break" then return true end
+  else
+    expr_stat()
+  end
+  return false
+end
+
+----------------------------------------------------------------------
+-- parse a chunk, which consists of a bunch of statements
+-- * used in parser(), body(), block(), repeat_stat()
+----------------------------------------------------------------------
+
+-- this is a forward-referenced local
+function chunk()
+  -- chunk -> { stat [';'] }
+  local islast = false
+  while not islast and not block_follow[tok] do
+    islast = stat()
+    testnext(";")
+  end
+end
+
+----------------------------------------------------------------------
+-- performs parsing, returns parsed data structure
+----------------------------------------------------------------------
+
+function parser()
+  open_func()
+  fs.is_vararg = true  -- main func. is always vararg
+  nextt()  -- read first token
+  chunk()
+  check("<eof>")
+  close_func()
+  return globalinfo, localinfo
+end
+
+----------------------------------------------------------------------
+-- initialization function
+----------------------------------------------------------------------
+
+function init(tokorig, seminfoorig, toklnorig)
+  tpos = 1                      -- token position
+  top_fs = {}                   -- reset top level function state
+  ------------------------------------------------------------------
+  -- set up grammar-only token tables; impedance-matching...
+  -- note that constants returned by the lexer is source-level, so
+  -- for now, fake(!) constant tokens (TK_NUMBER|TK_STRING|TK_LSTRING)
+  ------------------------------------------------------------------
+  local j = 1
+  toklist, seminfolist, toklnlist, xreflist = {}, {}, {}, {}
+  for i = 1, #tokorig do
+    local tok = tokorig[i]
+    local yep = true
+    if tok == "TK_KEYWORD" or tok == "TK_OP" then
+      tok = seminfoorig[i]
+    elseif tok == "TK_NAME" then
+      tok = "<name>"
+      seminfolist[j] = seminfoorig[i]
+    elseif tok == "TK_NUMBER" then
+      tok = "<number>"
+      seminfolist[j] = 0  -- fake!
+    elseif tok == "TK_STRING" or tok == "TK_LSTRING" then
+      tok = "<string>"
+      seminfolist[j] = ""  -- fake!
+    elseif tok == "TK_EOS" then
+      tok = "<eof>"
+    else
+      -- non-grammar tokens; ignore them
+      yep = false
+    end
+    if yep then  -- set rest of the information
+      toklist[j] = tok
+      toklnlist[j] = toklnorig[i]
+      xreflist[j] = i
+      j = j + 1
+    end
+  end--for
+  ------------------------------------------------------------------
+  -- initialize data structures for variable tracking
+  ------------------------------------------------------------------
+  globalinfo, globallookup, localinfo = {}, {}, {}
+  ilocalinfo, ilocalrefs = {}, {}
+end
+
+return _G
diff --git a/contrib/luasrcdiet/lua/optlex.lua b/contrib/luasrcdiet/lua/optlex.lua
new file mode 100644
index 000000000..4c46b918b
--- /dev/null
+++ b/contrib/luasrcdiet/lua/optlex.lua
@@ -0,0 +1,832 @@
+--[[--------------------------------------------------------------------
+
+  optlex.lua: does lexer-based optimizations
+  This file is part of LuaSrcDiet.
+
+  Copyright (c) 2008 Kein-Hong Man <khman@users.sf.net>
+  The COPYRIGHT file describes the conditions
+  under which this software may be distributed.
+
+  See the ChangeLog for more information.
+
+----------------------------------------------------------------------]]
+
+--[[--------------------------------------------------------------------
+-- NOTES:
+-- * For more lexer-based optimization ideas, see the TODO items or
+--   look at technotes.txt.
+-- * TODO: general string delimiter conversion optimizer
+-- * TODO: (numbers) warn if overly significant digit
+----------------------------------------------------------------------]]
+
+local base = _G
+local string = require "string"
+module "optlex"
+local match = string.match
+local sub = string.sub
+local find = string.find
+local rep = string.rep
+local print
+
+------------------------------------------------------------------------
+-- variables and data structures
+------------------------------------------------------------------------
+
+-- error function, can override by setting own function into module
+error = base.error
+
+warn = {}                       -- table for warning flags
+
+local stoks, sinfos, stoklns    -- source lists
+
+local is_realtoken = {          -- significant (grammar) tokens
+  TK_KEYWORD = true,
+  TK_NAME = true,
+  TK_NUMBER = true,
+  TK_STRING = true,
+  TK_LSTRING = true,
+  TK_OP = true,
+  TK_EOS = true,
+}
+local is_faketoken = {          -- whitespace (non-grammar) tokens
+  TK_COMMENT = true,
+  TK_LCOMMENT = true,
+  TK_EOL = true,
+  TK_SPACE = true,
+}
+
+local opt_details               -- for extra information
+
+------------------------------------------------------------------------
+-- true if current token is at the start of a line
+-- * skips over deleted tokens via recursion
+------------------------------------------------------------------------
+
+local function atlinestart(i)
+  local tok = stoks[i - 1]
+  if i <= 1 or tok == "TK_EOL" then
+    return true
+  elseif tok == "" then
+    return atlinestart(i - 1)
+  end
+  return false
+end
+
+------------------------------------------------------------------------
+-- true if current token is at the end of a line
+-- * skips over deleted tokens via recursion
+------------------------------------------------------------------------
+
+local function atlineend(i)
+  local tok = stoks[i + 1]
+  if i >= #stoks or tok == "TK_EOL" or tok == "TK_EOS" then
+    return true
+  elseif tok == "" then
+    return atlineend(i + 1)
+  end
+  return false
+end
+
+------------------------------------------------------------------------
+-- counts comment EOLs inside a long comment
+-- * in order to keep line numbering, EOLs need to be reinserted
+------------------------------------------------------------------------
+
+local function commenteols(lcomment)
+  local sep = #match(lcomment, "^%-%-%[=*%[")
+  local z = sub(lcomment, sep + 1, -(sep - 1))  -- remove delims
+  local i, c = 1, 0
+  while true do
+    local p, q, r, s = find(z, "([\r\n])([\r\n]?)", i)
+    if not p then break end     -- if no matches, done
+    i = p + 1
+    c = c + 1
+    if #s > 0 and r ~= s then   -- skip CRLF or LFCR
+      i = i + 1
+    end
+  end
+  return c
+end
+
+------------------------------------------------------------------------
+-- compares two tokens (i, j) and returns the whitespace required
+-- * important! see technotes.txt for more information
+-- * only two grammar/real tokens are being considered
+-- * if "", no separation is needed
+-- * if " ", then at least one whitespace (or EOL) is required
+------------------------------------------------------------------------
+
+local function checkpair(i, j)
+  local match = match
+  local t1, t2 = stoks[i], stoks[j]
+  --------------------------------------------------------------------
+  if t1 == "TK_STRING" or t1 == "TK_LSTRING" or
+     t2 == "TK_STRING" or t2 == "TK_LSTRING" then
+    return ""
+  --------------------------------------------------------------------
+  elseif t1 == "TK_OP" or t2 == "TK_OP" then
+    if (t1 == "TK_OP" and (t2 == "TK_KEYWORD" or t2 == "TK_NAME")) or
+       (t2 == "TK_OP" and (t1 == "TK_KEYWORD" or t1 == "TK_NAME")) then
+      return ""
+    end
+    if t1 == "TK_OP" and t2 == "TK_OP" then
+      -- for TK_OP/TK_OP pairs, see notes in technotes.txt
+      local op, op2 = sinfos[i], sinfos[j]
+      if (match(op, "^%.%.?$") and match(op2, "^%.")) or
+         (match(op, "^[~=<>]$") and op2 == "=") or
+         (op == "[" and (op2 == "[" or op2 == "=")) then
+        return " "
+      end
+      return ""
+    end
+    -- "TK_OP" + "TK_NUMBER" case
+    local op = sinfos[i]
+    if t2 == "TK_OP" then op = sinfos[j] end
+    if match(op, "^%.%.?%.?$") then
+      return " "
+    end
+    return ""
+  --------------------------------------------------------------------
+  else-- "TK_KEYWORD" | "TK_NAME" | "TK_NUMBER" then
+    return " "
+  --------------------------------------------------------------------
+  end
+end
+
+------------------------------------------------------------------------
+-- repack tokens, removing deletions caused by optimization process
+------------------------------------------------------------------------
+
+local function repack_tokens()
+  local dtoks, dinfos, dtoklns = {}, {}, {}
+  local j = 1
+  for i = 1, #stoks do
+    local tok = stoks[i]
+    if tok ~= "" then
+      dtoks[j], dinfos[j], dtoklns[j] = tok, sinfos[i], stoklns[i]
+      j = j + 1
+    end
+  end
+  stoks, sinfos, stoklns = dtoks, dinfos, dtoklns
+end
+
+------------------------------------------------------------------------
+-- number optimization
+-- * optimization using string formatting functions is one way of doing
+--   this, but here, we consider all cases and handle them separately
+--   (possibly an idiotic approach...)
+-- * scientific notation being generated is not in canonical form, this
+--   may or may not be a bad thing, feedback welcome
+-- * note: intermediate portions need to fit into a normal number range
+-- * optimizations can be divided based on number patterns:
+-- * hexadecimal:
+--   (1) no need to remove leading zeros, just skip to (2)
+--   (2) convert to integer if size equal or smaller
+--       * change if equal size -> lose the 'x' to reduce entropy
+--   (3) number is then processed as an integer
+--   (4) note: does not make 0[xX] consistent
+-- * integer:
+--   (1) note: includes anything with trailing ".", ".0", ...
+--   (2) remove useless fractional part, if present, e.g. 123.000
+--   (3) remove leading zeros, e.g. 000123
+--   (4) switch to scientific if shorter, e.g. 123000 -> 123e3
+-- * with fraction:
+--   (1) split into digits dot digits
+--   (2) if no integer portion, take as zero (can omit later)
+--   (3) handle degenerate .000 case, after which the fractional part
+--       must be non-zero (if zero, it's matched as an integer)
+--   (4) remove trailing zeros for fractional portion
+--   (5) p.q where p > 0 and q > 0 cannot be shortened any more
+--   (6) otherwise p == 0 and the form is .q, e.g. .000123
+--   (7) if scientific shorter, convert, e.g. .000123 -> 123e-6
+-- * scientific:
+--   (1) split into (digits dot digits) [eE] ([+-] digits)
+--   (2) if significand has ".", shift it out so it becomes an integer
+--   (3) if significand is zero, just use zero
+--   (4) remove leading zeros for significand
+--   (5) shift out trailing zeros for significand
+--   (6) examine exponent and determine which format is best:
+--       integer, with fraction, scientific
+------------------------------------------------------------------------
+
+local function do_number(i)
+  local before = sinfos[i]      -- 'before'
+  local z = before              -- working representation
+  local y                       -- 'after', if better
+  --------------------------------------------------------------------
+  if match(z, "^0[xX]") then            -- hexadecimal number
+    local v = base.tostring(base.tonumber(z))
+    if #v <= #z then
+      z = v  -- change to integer, AND continue
+    else
+      return  -- no change; stick to hex
+    end
+  end
+  --------------------------------------------------------------------
+  if match(z, "^%d+%.?0*$") then        -- integer or has useless frac
+    z = match(z, "^(%d+)%.?0*$")  -- int portion only
+    if z + 0 > 0 then
+      z = match(z, "^0*([1-9]%d*)$")  -- remove leading zeros
+      local v = #match(z, "0*$")
+      local nv = base.tostring(v)
+      if v > #nv + 1 then  -- scientific is shorter
+        z = sub(z, 1, #z - v).."e"..nv
+      end
+      y = z
+    else
+      y = "0"  -- basic zero
+    end
+  --------------------------------------------------------------------
+  elseif not match(z, "[eE]") then      -- number with fraction part
+    local p, q = match(z, "^(%d*)%.(%d+)$")  -- split
+    if p == "" then p = 0 end  -- int part zero
+    if q + 0 == 0 and p == 0 then
+      y = "0"  -- degenerate .000 case
+    else
+      -- now, q > 0 holds and p is a number
+      local v = #match(q, "0*$")  -- remove trailing zeros
+      if v > 0 then
+        q = sub(q, 1, #q - v)
+      end
+      -- if p > 0, nothing else we can do to simplify p.q case
+      if p + 0 > 0 then
+        y = p.."."..q
+      else
+        y = "."..q  -- tentative, e.g. .000123
+        local v = #match(q, "^0*")  -- # leading spaces
+        local w = #q - v            -- # significant digits
+        local nv = base.tostring(#q)
+        -- e.g. compare 123e-6 versus .000123
+        if w + 2 + #nv < 1 + #q then
+          y = sub(q, -w).."e-"..nv
+        end
+      end
+    end
+  --------------------------------------------------------------------
+  else                                  -- scientific number
+    local sig, ex = match(z, "^([^eE]+)[eE]([%+%-]?%d+)$")
+    ex = base.tonumber(ex)
+    -- if got ".", shift out fractional portion of significand
+    local p, q = match(sig, "^(%d*)%.(%d*)$")
+    if p then
+      ex = ex - #q
+      sig = p..q
+    end
+    if sig + 0 == 0 then
+      y = "0"  -- basic zero
+    else
+      local v = #match(sig, "^0*")  -- remove leading zeros
+      sig = sub(sig, v + 1)
+      v = #match(sig, "0*$") -- shift out trailing zeros
+      if v > 0 then
+        sig = sub(sig, 1, #sig - v)
+        ex = ex + v
+      end
+      -- examine exponent and determine which format is best
+      local nex = base.tostring(ex)
+      if ex == 0 then  -- it's just an integer
+        y = sig
+      elseif ex > 0 and (ex <= 1 + #nex) then  -- a number
+        y = sig..rep("0", ex)
+      elseif ex < 0 and (ex >= -#sig) then  -- fraction, e.g. .123
+        v = #sig + ex
+        y = sub(sig, 1, v).."."..sub(sig, v + 1)
+      elseif ex < 0 and (#nex >= -ex - #sig) then
+        -- e.g. compare 1234e-5 versus .01234
+        -- gives: #sig + 1 + #nex >= 1 + (-ex - #sig) + #sig
+        --     -> #nex >= -ex - #sig
+        v = -ex - #sig
+        y = "."..rep("0", v)..sig
+      else  -- non-canonical scientific representation
+        y = sig.."e"..ex
+      end
+    end--if sig
+  end
+  --------------------------------------------------------------------
+  if y and y ~= sinfos[i] then
+    if opt_details then
+      print("<number> (line "..stoklns[i]..") "..sinfos[i].." -> "..y)
+      opt_details = opt_details + 1
+    end
+    sinfos[i] = y
+  end
+end
+
+------------------------------------------------------------------------
+-- string optimization
+-- * note: works on well-formed strings only!
+-- * optimizations on characters can be summarized as follows:
+--   \a\b\f\n\r\t\v -- no change
+--   \\ -- no change
+--   \"\' -- depends on delim, other can remove \
+--   \[\] -- remove \
+--   \<char> -- general escape, remove \
+--   \<eol> -- normalize the EOL only
+--   \ddd -- if \a\b\f\n\r\t\v, change to latter
+--           if other < ascii 32, keep ddd but zap leading zeros
+--           if >= ascii 32, translate it into the literal, then also
+--                           do escapes for \\,\",\' cases
+--   <other> -- no change
+-- * switch delimiters if string becomes shorter
+------------------------------------------------------------------------
+
+local function do_string(I)
+  local info = sinfos[I]
+  local delim = sub(info, 1, 1)                 -- delimiter used
+  local ndelim = (delim == "'") and '"' or "'"  -- opposite " <-> '
+  local z = sub(info, 2, -2)                    -- actual string
+  local i = 1
+  local c_delim, c_ndelim = 0, 0                -- "/' counts
+  --------------------------------------------------------------------
+  while i <= #z do
+    local c = sub(z, i, i)
+    ----------------------------------------------------------------
+    if c == "\\" then                   -- escaped stuff
+      local j = i + 1
+      local d = sub(z, j, j)
+      local p = find("abfnrtv\\\n\r\"\'0123456789", d, 1, true)
+      ------------------------------------------------------------
+      if not p then                     -- \<char> -- remove \
+        z = sub(z, 1, i - 1)..sub(z, j)
+        i = i + 1
+      ------------------------------------------------------------
+      elseif p <= 8 then                -- \a\b\f\n\r\t\v\\
+        i = i + 2                       -- no change
+      ------------------------------------------------------------
+      elseif p <= 10 then               -- \<eol> -- normalize EOL
+        local eol = sub(z, j, j + 1)
+        if eol == "\r\n" or eol == "\n\r" then
+          z = sub(z, 1, i).."\n"..sub(z, j + 2)
+        elseif p == 10 then  -- \r case
+          z = sub(z, 1, i).."\n"..sub(z, j + 1)
+        end
+        i = i + 2
+      ------------------------------------------------------------
+      elseif p <= 12 then               -- \"\' -- remove \ for ndelim
+        if d == delim then
+          c_delim = c_delim + 1
+          i = i + 2
+        else
+          c_ndelim = c_ndelim + 1
+          z = sub(z, 1, i - 1)..sub(z, j)
+          i = i + 1
+        end
+      ------------------------------------------------------------
+      else                              -- \ddd -- various steps
+        local s = match(z, "^(%d%d?%d?)", j)
+        j = i + 1 + #s                  -- skip to location
+        local cv = s + 0
+        local cc = string.char(cv)
+        local p = find("\a\b\f\n\r\t\v", cc, 1, true)
+        if p then                       -- special escapes
+          s = "\\"..sub("abfnrtv", p, p)
+        elseif cv < 32 then             -- normalized \ddd
+          s = "\\"..cv
+        elseif cc == delim then         -- \<delim>
+          s = "\\"..cc
+          c_delim = c_delim + 1
+        elseif cc == "\\" then          -- \\
+          s = "\\\\"
+        else                            -- literal character
+          s = cc
+          if cc == ndelim then
+            c_ndelim = c_ndelim + 1
+          end
+        end
+        z = sub(z, 1, i - 1)..s..sub(z, j)
+        i = i + #s
+      ------------------------------------------------------------
+      end--if p
+    ----------------------------------------------------------------
+    else-- c ~= "\\"                    -- <other> -- no change
+      i = i + 1
+      if c == ndelim then  -- count ndelim, for switching delimiters
+        c_ndelim = c_ndelim + 1
+      end
+    ----------------------------------------------------------------
+    end--if c
+  end--while
+  --------------------------------------------------------------------
+  -- switching delimiters, a long-winded derivation:
+  -- (1) delim takes 2+2*c_delim bytes, ndelim takes c_ndelim bytes
+  -- (2) delim becomes c_delim bytes, ndelim becomes 2+2*c_ndelim bytes
+  -- simplifying the condition (1)>(2) --> c_delim > c_ndelim
+  if c_delim > c_ndelim then
+    i = 1
+    while i <= #z do
+      local p, q, r = find(z, "([\'\"])", i)
+      if not p then break end
+      if r == delim then                -- \<delim> -> <delim>
+        z = sub(z, 1, p - 2)..sub(z, p)
+        i = p
+      else-- r == ndelim                -- <ndelim> -> \<ndelim>
+        z = sub(z, 1, p - 1).."\\"..sub(z, p)
+        i = p + 2
+      end
+    end--while
+    delim = ndelim  -- actually change delimiters
+  end
+  --------------------------------------------------------------------
+  z = delim..z..delim
+  if z ~= sinfos[I] then
+    if opt_details then
+      print("<string> (line "..stoklns[I]..") "..sinfos[I].." -> "..z)
+      opt_details = opt_details + 1
+    end
+    sinfos[I] = z
+  end
+end
+
+------------------------------------------------------------------------
+-- long string optimization
+-- * note: warning flagged if trailing whitespace found, not trimmed
+-- * remove first optional newline
+-- * normalize embedded newlines
+-- * reduce '=' separators in delimiters if possible
+------------------------------------------------------------------------
+
+local function do_lstring(I)
+  local info = sinfos[I]
+  local delim1 = match(info, "^%[=*%[")  -- cut out delimiters
+  local sep = #delim1
+  local delim2 = sub(info, -sep, -1)
+  local z = sub(info, sep + 1, -(sep + 1))  -- lstring without delims
+  local y = ""
+  local i = 1
+  --------------------------------------------------------------------
+  while true do
+    local p, q, r, s = find(z, "([\r\n])([\r\n]?)", i)
+    -- deal with a single line
+    local ln
+    if not p then
+      ln = sub(z, i)
+    elseif p >= i then
+      ln = sub(z, i, p - 1)
+    end
+    if ln ~= "" then
+      -- flag a warning if there are trailing spaces, won't optimize!
+      if match(ln, "%s+$") then
+        warn.lstring = "trailing whitespace in long string near line "..stoklns[I]
+      end
+      y = y..ln
+    end
+    if not p then  -- done if no more EOLs
+      break
+    end
+    -- deal with line endings, normalize them
+    i = p + 1
+    if p then
+      if #s > 0 and r ~= s then  -- skip CRLF or LFCR
+        i = i + 1
+      end
+      -- skip first newline, which can be safely deleted
+      if not(i == 1 and i == p) then
+        y = y.."\n"
+      end
+    end
+  end--while
+  --------------------------------------------------------------------
+  -- handle possible deletion of one or more '=' separators
+  if sep >= 3 then
+    local chk, okay = sep - 1
+    -- loop to test ending delimiter with less of '=' down to zero
+    while chk >= 2 do
+      local delim = "%]"..rep("=", chk - 2).."%]"
+      if not match(y, delim) then okay = chk end
+      chk = chk - 1
+    end
+    if okay then  -- change delimiters
+      sep = rep("=", okay - 2)
+      delim1, delim2 = "["..sep.."[", "]"..sep.."]"
+    end
+  end
+  --------------------------------------------------------------------
+  sinfos[I] = delim1..y..delim2
+end
+
+------------------------------------------------------------------------
+-- long comment optimization
+-- * note: does not remove first optional newline
+-- * trim trailing whitespace
+-- * normalize embedded newlines
+-- * reduce '=' separators in delimiters if possible
+------------------------------------------------------------------------
+
+local function do_lcomment(I)
+  local info = sinfos[I]
+  local delim1 = match(info, "^%-%-%[=*%[")  -- cut out delimiters
+  local sep = #delim1
+  local delim2 = sub(info, -sep, -1)
+  local z = sub(info, sep + 1, -(sep - 1))  -- comment without delims
+  local y = ""
+  local i = 1
+  --------------------------------------------------------------------
+  while true do
+    local p, q, r, s = find(z, "([\r\n])([\r\n]?)", i)
+    -- deal with a single line, extract and check trailing whitespace
+    local ln
+    if not p then
+      ln = sub(z, i)
+    elseif p >= i then
+      ln = sub(z, i, p - 1)
+    end
+    if ln ~= "" then
+      -- trim trailing whitespace if non-empty line
+      local ws = match(ln, "%s*$")
+      if #ws > 0 then ln = sub(ln, 1, -(ws + 1)) end
+      y = y..ln
+    end
+    if not p then  -- done if no more EOLs
+      break
+    end
+    -- deal with line endings, normalize them
+    i = p + 1
+    if p then
+      if #s > 0 and r ~= s then  -- skip CRLF or LFCR
+        i = i + 1
+      end
+      y = y.."\n"
+    end
+  end--while
+  --------------------------------------------------------------------
+  -- handle possible deletion of one or more '=' separators
+  sep = sep - 2
+  if sep >= 3 then
+    local chk, okay = sep - 1
+    -- loop to test ending delimiter with less of '=' down to zero
+    while chk >= 2 do
+      local delim = "%]"..rep("=", chk - 2).."%]"
+      if not match(y, delim) then okay = chk end
+      chk = chk - 1
+    end
+    if okay then  -- change delimiters
+      sep = rep("=", okay - 2)
+      delim1, delim2 = "--["..sep.."[", "]"..sep.."]"
+    end
+  end
+  --------------------------------------------------------------------
+  sinfos[I] = delim1..y..delim2
+end
+
+------------------------------------------------------------------------
+-- short comment optimization
+-- * trim trailing whitespace
+------------------------------------------------------------------------
+
+local function do_comment(i)
+  local info = sinfos[i]
+  local ws = match(info, "%s*$")        -- just look from end of string
+  if #ws > 0 then
+    info = sub(info, 1, -(ws + 1))      -- trim trailing whitespace
+  end
+  sinfos[i] = info
+end
+
+------------------------------------------------------------------------
+-- returns true if string found in long comment
+-- * this is a feature to keep copyright or license texts
+------------------------------------------------------------------------
+
+local function keep_lcomment(opt_keep, info)
+  if not opt_keep then return false end  -- option not set
+  local delim1 = match(info, "^%-%-%[=*%[")  -- cut out delimiters
+  local sep = #delim1
+  local delim2 = sub(info, -sep, -1)
+  local z = sub(info, sep + 1, -(sep - 1))  -- comment without delims
+  if find(z, opt_keep, 1, true) then  -- try to match
+    return true
+  end
+end
+
+------------------------------------------------------------------------
+-- main entry point
+-- * currently, lexer processing has 2 passes
+-- * processing is done on a line-oriented basis, which is easier to
+--   grok due to the next point...
+-- * since there are various options that can be enabled or disabled,
+--   processing is a little messy or convoluted
+------------------------------------------------------------------------
+
+function optimize(option, toklist, semlist, toklnlist)
+  --------------------------------------------------------------------
+  -- set option flags
+  --------------------------------------------------------------------
+  local opt_comments = option["opt-comments"]
+  local opt_whitespace = option["opt-whitespace"]
+  local opt_emptylines = option["opt-emptylines"]
+  local opt_eols = option["opt-eols"]
+  local opt_strings = option["opt-strings"]
+  local opt_numbers = option["opt-numbers"]
+  local opt_keep = option.KEEP
+  opt_details = option.DETAILS and 0  -- upvalues for details display
+  print = print or base.print
+  if opt_eols then  -- forced settings, otherwise won't work properly
+    opt_comments = true
+    opt_whitespace = true
+    opt_emptylines = true
+  end
+  --------------------------------------------------------------------
+  -- variable initialization
+  --------------------------------------------------------------------
+  stoks, sinfos, stoklns                -- set source lists
+    = toklist, semlist, toklnlist
+  local i = 1                           -- token position
+  local tok, info                       -- current token
+  local prev    -- position of last grammar token
+                -- on same line (for TK_SPACE stuff)
+  --------------------------------------------------------------------
+  -- changes a token, info pair
+  --------------------------------------------------------------------
+  local function settoken(tok, info, I)
+    I = I or i
+    stoks[I] = tok or ""
+    sinfos[I] = info or ""
+  end
+  --------------------------------------------------------------------
+  -- processing loop (PASS 1)
+  --------------------------------------------------------------------
+  while true do
+    tok, info = stoks[i], sinfos[i]
+    ----------------------------------------------------------------
+    local atstart = atlinestart(i)      -- set line begin flag
+    if atstart then prev = nil end
+    ----------------------------------------------------------------
+    if tok == "TK_EOS" then             -- end of stream/pass
+      break
+    ----------------------------------------------------------------
+    elseif tok == "TK_KEYWORD" or       -- keywords, identifiers,
+           tok == "TK_NAME" or          -- operators
+           tok == "TK_OP" then
+      -- TK_KEYWORD and TK_OP can't be optimized without a big
+      -- optimization framework; it would be more of an optimizing
+      -- compiler, not a source code compressor
+      -- TK_NAME that are locals needs parser to analyze/optimize
+      prev = i
+    ----------------------------------------------------------------
+    elseif tok == "TK_NUMBER" then      -- numbers
+      if opt_numbers then
+        do_number(i)  -- optimize
+      end
+      prev = i
+    ----------------------------------------------------------------
+    elseif tok == "TK_STRING" or        -- strings, long strings
+           tok == "TK_LSTRING" then
+      if opt_strings then
+        if tok == "TK_STRING" then
+          do_string(i)  -- optimize
+        else
+          do_lstring(i)  -- optimize
+        end
+      end
+      prev = i
+    ----------------------------------------------------------------
+    elseif tok == "TK_COMMENT" then     -- short comments
+      if opt_comments then
+        if i == 1 and sub(info, 1, 1) == "#" then
+          -- keep shbang comment, trim whitespace
+          do_comment(i)
+        else
+          -- safe to delete, as a TK_EOL (or TK_EOS) always follows
+          settoken()  -- remove entirely
+        end
+      elseif opt_whitespace then        -- trim whitespace only
+        do_comment(i)
+      end
+    ----------------------------------------------------------------
+    elseif tok == "TK_LCOMMENT" then    -- long comments
+      if keep_lcomment(opt_keep, info) then
+        ------------------------------------------------------------
+        -- if --keep, we keep a long comment if <msg> is found;
+        -- this is a feature to keep copyright or license texts
+        if opt_whitespace then          -- trim whitespace only
+          do_lcomment(i)
+        end
+        prev = i
+      elseif opt_comments then
+        local eols = commenteols(info)
+        ------------------------------------------------------------
+        -- prepare opt_emptylines case first, if a disposable token
+        -- follows, current one is safe to dump, else keep a space;
+        -- it is implied that the operation is safe for '-', because
+        -- current is a TK_LCOMMENT, and must be separate from a '-'
+        if is_faketoken[stoks[i + 1]] then
+          settoken()  -- remove entirely
+          tok = ""
+        else
+          settoken("TK_SPACE", " ")
+        end
+        ------------------------------------------------------------
+        -- if there are embedded EOLs to keep and opt_emptylines is
+        -- disabled, then switch the token into one or more EOLs
+        if not opt_emptylines and eols > 0 then
+          settoken("TK_EOL", rep("\n", eols))
+        end
+        ------------------------------------------------------------
+        -- if optimizing whitespaces, force reinterpretation of the
+        -- token to give a chance for the space to be optimized away
+        if opt_whitespace and tok ~= "" then
+          i = i - 1  -- to reinterpret
+        end
+        ------------------------------------------------------------
+      else                              -- disabled case
+        if opt_whitespace then          -- trim whitespace only
+          do_lcomment(i)
+        end
+        prev = i
+      end
+    ----------------------------------------------------------------
+    elseif tok == "TK_EOL" then         -- line endings
+      if atstart and opt_emptylines then
+        settoken()  -- remove entirely
+      elseif info == "\r\n" or info == "\n\r" then
+        -- normalize the rest of the EOLs for CRLF/LFCR only
+        -- (note that TK_LCOMMENT can change into several EOLs)
+        settoken("TK_EOL", "\n")
+      end
+    ----------------------------------------------------------------
+    elseif tok == "TK_SPACE" then       -- whitespace
+      if opt_whitespace then
+        if atstart or atlineend(i) then
+          -- delete leading and trailing whitespace
+          settoken()  -- remove entirely
+        else
+          ------------------------------------------------------------
+          -- at this point, since leading whitespace have been removed,
+          -- there should be a either a real token or a TK_LCOMMENT
+          -- prior to hitting this whitespace; the TK_LCOMMENT case
+          -- only happens if opt_comments is disabled; so prev ~= nil
+          local ptok = stoks[prev]
+          if ptok == "TK_LCOMMENT" then
+            -- previous TK_LCOMMENT can abut with anything
+            settoken()  -- remove entirely
+          else
+            -- prev must be a grammar token; consecutive TK_SPACE
+            -- tokens is impossible when optimizing whitespace
+            local ntok = stoks[i + 1]
+            if is_faketoken[ntok] then
+              -- handle special case where a '-' cannot abut with
+              -- either a short comment or a long comment
+              if (ntok == "TK_COMMENT" or ntok == "TK_LCOMMENT") and
+                 ptok == "TK_OP" and sinfos[prev] == "-" then
+                -- keep token
+              else
+                settoken()  -- remove entirely
+              end
+            else--is_realtoken
+              -- check a pair of grammar tokens, if can abut, then
+              -- delete space token entirely, otherwise keep one space
+              local s = checkpair(prev, i + 1)
+              if s == "" then
+                settoken()  -- remove entirely
+              else
+                settoken("TK_SPACE", " ")
+              end
+            end
+          end
+          ------------------------------------------------------------
+        end
+      end
+    ----------------------------------------------------------------
+    else
+      error("unidentified token encountered")
+    end
+    ----------------------------------------------------------------
+    i = i + 1
+  end--while
+  repack_tokens()
+  --------------------------------------------------------------------
+  -- processing loop (PASS 2)
+  --------------------------------------------------------------------
+  if opt_eols then
+    i = 1
+    -- aggressive EOL removal only works with most non-grammar tokens
+    -- optimized away because it is a rather simple scheme -- basically
+    -- it just checks 'real' token pairs around EOLs
+    if stoks[1] == "TK_COMMENT" then
+      -- first comment still existing must be shbang, skip whole line
+      i = 3
+    end
+    while true do
+      tok, info = stoks[i], sinfos[i]
+      --------------------------------------------------------------
+      if tok == "TK_EOS" then           -- end of stream/pass
+        break
+      --------------------------------------------------------------
+      elseif tok == "TK_EOL" then       -- consider each TK_EOL
+        local t1, t2 = stoks[i - 1], stoks[i + 1]
+        if is_realtoken[t1] and is_realtoken[t2] then  -- sanity check
+          local s = checkpair(i - 1, i + 1)
+          if s == "" then
+            settoken()  -- remove entirely
+          end
+        end
+      end--if tok
+      --------------------------------------------------------------
+      i = i + 1
+    end--while
+    repack_tokens()
+  end
+  --------------------------------------------------------------------
+  if opt_details and opt_details > 0 then print() end -- spacing
+  return stoks, sinfos, stoklns
+end
diff --git a/contrib/luasrcdiet/lua/optparser.lua b/contrib/luasrcdiet/lua/optparser.lua
new file mode 100644
index 000000000..cfe6cc101
--- /dev/null
+++ b/contrib/luasrcdiet/lua/optparser.lua
@@ -0,0 +1,564 @@
+--[[--------------------------------------------------------------------
+
+  optparser.lua: does parser-based optimizations
+  This file is part of LuaSrcDiet.
+
+  Copyright (c) 2008 Kein-Hong Man <khman@users.sf.net>
+  The COPYRIGHT file describes the conditions
+  under which this software may be distributed.
+
+  See the ChangeLog for more information.
+
+----------------------------------------------------------------------]]
+
+--[[--------------------------------------------------------------------
+-- NOTES:
+-- * For more parser-based optimization ideas, see the TODO items or
+--   look at technotes.txt.
+-- * The processing load is quite significant, but since this is an
+--   off-line text processor, I believe we can wait a few seconds.
+-- * TODO: might process "local a,a,a" wrongly... need tests!
+-- * TODO: remove position handling if overlapped locals (rem < 0)
+--   needs more study, to check behaviour
+-- * TODO: there are probably better ways to do allocation, e.g. by
+--   choosing better methods to sort and pick locals...
+-- * TODO: we don't need 53*63 two-letter identifiers; we can make
+--   do with significantly less depending on how many that are really
+--   needed and improve entropy; e.g. 13 needed -> choose 4*4 instead
+----------------------------------------------------------------------]]
+
+local base = _G
+local string = require "string"
+local table = require "table"
+module "optparser"
+
+----------------------------------------------------------------------
+-- Letter frequencies for reducing symbol entropy (fixed version)
+-- * Might help a wee bit when the output file is compressed
+-- * See Wikipedia: http://en.wikipedia.org/wiki/Letter_frequencies
+-- * We use letter frequencies according to a Linotype keyboard, plus
+--   the underscore, and both lower case and upper case letters.
+-- * The arrangement below (LC, underscore, %d, UC) is arbitrary.
+-- * This is certainly not optimal, but is quick-and-dirty and the
+--   process has no significant overhead
+----------------------------------------------------------------------
+
+local LETTERS = "etaoinshrdlucmfwypvbgkqjxz_ETAOINSHRDLUCMFWYPVBGKQJXZ"
+local ALPHANUM = "etaoinshrdlucmfwypvbgkqjxz_0123456789ETAOINSHRDLUCMFWYPVBGKQJXZ"
+
+-- names or identifiers that must be skipped
+-- * the first two lines are for keywords
+local SKIP_NAME = {}
+for v in string.gmatch([[
+and break do else elseif end false for function if in
+local nil not or repeat return then true until while
+self]], "%S+") do
+  SKIP_NAME[v] = true
+end
+
+------------------------------------------------------------------------
+-- variables and data structures
+------------------------------------------------------------------------
+
+local toklist, seminfolist,             -- token lists
+      globalinfo, localinfo,            -- variable information tables
+      globaluniq, localuniq,            -- unique name tables
+      var_new,                          -- index of new variable names
+      varlist                           -- list of output variables
+
+----------------------------------------------------------------------
+-- preprocess information table to get lists of unique names
+----------------------------------------------------------------------
+
+local function preprocess(infotable)
+  local uniqtable = {}
+  for i = 1, #infotable do              -- enumerate info table
+    local obj = infotable[i]
+    local name = obj.name
+    --------------------------------------------------------------------
+    if not uniqtable[name] then         -- not found, start an entry
+      uniqtable[name] = {
+        decl = 0, token = 0, size = 0,
+      }
+    end
+    --------------------------------------------------------------------
+    local uniq = uniqtable[name]        -- count declarations, tokens, size
+    uniq.decl = uniq.decl + 1
+    local xref = obj.xref
+    local xcount = #xref
+    uniq.token = uniq.token + xcount
+    uniq.size = uniq.size + xcount * #name
+    --------------------------------------------------------------------
+    if obj.decl then            -- if local table, create first,last pairs
+      obj.id = i
+      obj.xcount = xcount
+      if xcount > 1 then        -- if ==1, means local never accessed
+        obj.first = xref[2]
+        obj.last = xref[xcount]
+      end
+    --------------------------------------------------------------------
+    else                        -- if global table, add a back ref
+      uniq.id = i
+    end
+    --------------------------------------------------------------------
+  end--for
+  return uniqtable
+end
+
+----------------------------------------------------------------------
+-- calculate actual symbol frequencies, in order to reduce entropy
+-- * this may help further reduce the size of compressed sources
+-- * note that since parsing optimizations is put before lexing
+--   optimizations, the frequency table is not exact!
+-- * yes, this will miss --keep block comments too...
+----------------------------------------------------------------------
+
+local function recalc_for_entropy(option)
+  local byte = string.byte
+  local char = string.char
+  -- table of token classes to accept in calculating symbol frequency
+  local ACCEPT = {
+    TK_KEYWORD = true, TK_NAME = true, TK_NUMBER = true,
+    TK_STRING = true, TK_LSTRING = true,
+  }
+  if not option["opt-comments"] then
+    ACCEPT.TK_COMMENT = true
+    ACCEPT.TK_LCOMMENT = true
+  end
+  --------------------------------------------------------------------
+  -- create a new table and remove any original locals by filtering
+  --------------------------------------------------------------------
+  local filtered = {}
+  for i = 1, #toklist do
+    filtered[i] = seminfolist[i]
+  end
+  for i = 1, #localinfo do              -- enumerate local info table
+    local obj = localinfo[i]
+    local xref = obj.xref
+    for j = 1, obj.xcount do
+      local p = xref[j]
+      filtered[p] = ""                  -- remove locals
+    end
+  end
+  --------------------------------------------------------------------
+  local freq = {}                       -- reset symbol frequency table
+  for i = 0, 255 do freq[i] = 0 end
+  for i = 1, #toklist do                -- gather symbol frequency
+    local tok, info = toklist[i], filtered[i]
+    if ACCEPT[tok] then
+      for j = 1, #info do
+        local c = byte(info, j)
+        freq[c] = freq[c] + 1
+      end
+    end--if
+  end--for
+  --------------------------------------------------------------------
+  -- function to re-sort symbols according to actual frequencies
+  --------------------------------------------------------------------
+  local function resort(symbols)
+    local symlist = {}
+    for i = 1, #symbols do              -- prepare table to sort
+      local c = byte(symbols, i)
+      symlist[i] = { c = c, freq = freq[c], }
+    end
+    table.sort(symlist,                 -- sort selected symbols
+      function(v1, v2)
+        return v1.freq > v2.freq
+      end
+    )
+    local charlist = {}                 -- reconstitute the string
+    for i = 1, #symlist do
+      charlist[i] = char(symlist[i].c)
+    end
+    return table.concat(charlist)
+  end
+  --------------------------------------------------------------------
+  LETTERS = resort(LETTERS)             -- change letter arrangement
+  ALPHANUM = resort(ALPHANUM)
+end
+
+----------------------------------------------------------------------
+-- returns a string containing a new local variable name to use, and
+-- a flag indicating whether it collides with a global variable
+-- * trapping keywords and other names like 'self' is done elsewhere
+----------------------------------------------------------------------
+
+local function new_var_name()
+  local var
+  local cletters, calphanum = #LETTERS, #ALPHANUM
+  local v = var_new
+  if v < cletters then                  -- single char
+    v = v + 1
+    var = string.sub(LETTERS, v, v)
+  else                                  -- longer names
+    local range, sz = cletters, 1       -- calculate # chars fit
+    repeat
+      v = v - range
+      range = range * calphanum
+      sz = sz + 1
+    until range > v
+    local n = v % cletters              -- left side cycles faster
+    v = (v - n) / cletters              -- do first char first
+    n = n + 1
+    var = string.sub(LETTERS, n, n)
+    while sz > 1 do
+      local m = v % calphanum
+      v = (v - m) / calphanum
+      m = m + 1
+      var = var..string.sub(ALPHANUM, m, m)
+      sz = sz - 1
+    end
+  end
+  var_new = var_new + 1
+  return var, globaluniq[var] ~= nil
+end
+
+----------------------------------------------------------------------
+-- calculate and print some statistics
+-- * probably better in main source, put here for now
+----------------------------------------------------------------------
+
+local function stats_summary(globaluniq, localuniq, afteruniq, option)
+  local print = print or base.print
+  local fmt = string.format
+  local opt_details = option.DETAILS
+  local uniq_g , uniq_li, uniq_lo, uniq_ti, uniq_to,  -- stats needed
+        decl_g, decl_li, decl_lo, decl_ti, decl_to,
+        token_g, token_li, token_lo, token_ti, token_to,
+        size_g, size_li, size_lo, size_ti, size_to
+    = 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+  local function avg(c, l)              -- safe average function
+    if c == 0 then return 0 end
+    return l / c
+  end
+  --------------------------------------------------------------------
+  -- collect statistics (note: globals do not have declarations!)
+  --------------------------------------------------------------------
+  for name, uniq in base.pairs(globaluniq) do
+    uniq_g = uniq_g + 1
+    token_g = token_g + uniq.token
+    size_g = size_g + uniq.size
+  end
+  for name, uniq in base.pairs(localuniq) do
+    uniq_li = uniq_li + 1
+    decl_li = decl_li + uniq.decl
+    token_li = token_li + uniq.token
+    size_li = size_li + uniq.size
+  end
+  for name, uniq in base.pairs(afteruniq) do
+    uniq_lo = uniq_lo + 1
+    decl_lo = decl_lo + uniq.decl
+    token_lo = token_lo + uniq.token
+    size_lo = size_lo + uniq.size
+  end
+  uniq_ti = uniq_g + uniq_li
+  decl_ti = decl_g + decl_li
+  token_ti = token_g + token_li
+  size_ti = size_g + size_li
+  uniq_to = uniq_g + uniq_lo
+  decl_to = decl_g + decl_lo
+  token_to = token_g + token_lo
+  size_to = size_g + size_lo
+  --------------------------------------------------------------------
+  -- detailed stats: global list
+  --------------------------------------------------------------------
+  if opt_details then
+    local sorted = {} -- sort table of unique global names by size
+    for name, uniq in base.pairs(globaluniq) do
+      uniq.name = name
+      sorted[#sorted + 1] = uniq
+    end
+    table.sort(sorted,
+      function(v1, v2)
+        return v1.size > v2.size
+      end
+    )
+    local tabf1, tabf2 = "%8s%8s%10s  %s", "%8d%8d%10.2f  %s"
+    local hl = string.rep("-", 44)
+    print("*** global variable list (sorted by size) ***\n"..hl)
+    print(fmt(tabf1, "Token",  "Input", "Input", "Global"))
+    print(fmt(tabf1, "Count", "Bytes", "Average", "Name"))
+    print(hl)
+    for i = 1, #sorted do
+      local uniq = sorted[i]
+      print(fmt(tabf2, uniq.token, uniq.size, avg(uniq.token, uniq.size), uniq.name))
+    end
+    print(hl)
+    print(fmt(tabf2, token_g, size_g, avg(token_g, size_g), "TOTAL"))
+    print(hl.."\n")
+  --------------------------------------------------------------------
+  -- detailed stats: local list
+  --------------------------------------------------------------------
+    local tabf1, tabf2 = "%8s%8s%8s%10s%8s%10s  %s", "%8d%8d%8d%10.2f%8d%10.2f  %s"
+    local hl = string.rep("-", 70)
+    print("*** local variable list (sorted by allocation order) ***\n"..hl)
+    print(fmt(tabf1, "Decl.", "Token",  "Input", "Input", "Output", "Output", "Global"))
+    print(fmt(tabf1, "Count", "Count", "Bytes", "Average", "Bytes", "Average", "Name"))
+    print(hl)
+    for i = 1, #varlist do  -- iterate according to order assigned
+      local name = varlist[i]
+      local uniq = afteruniq[name]
+      local old_t, old_s = 0, 0
+      for j = 1, #localinfo do  -- find corresponding old names and calculate
+        local obj = localinfo[j]
+        if obj.name == name then
+          old_t = old_t + obj.xcount
+          old_s = old_s + obj.xcount * #obj.oldname
+        end
+      end
+      print(fmt(tabf2, uniq.decl, uniq.token, old_s, avg(old_t, old_s),
+                uniq.size, avg(uniq.token, uniq.size), name))
+    end
+    print(hl)
+    print(fmt(tabf2, decl_lo, token_lo, size_li, avg(token_li, size_li),
+              size_lo, avg(token_lo, size_lo), "TOTAL"))
+    print(hl.."\n")
+  end--if opt_details
+  --------------------------------------------------------------------
+  -- display output
+  --------------------------------------------------------------------
+  local tabf1, tabf2 = "%-16s%8s%8s%8s%8s%10s", "%-16s%8d%8d%8d%8d%10.2f"
+  local hl = string.rep("-", 58)
+  print("*** local variable optimization summary ***\n"..hl)
+  print(fmt(tabf1, "Variable",  "Unique", "Decl.", "Token", "Size", "Average"))
+  print(fmt(tabf1, "Types", "Names", "Count", "Count", "Bytes", "Bytes"))
+  print(hl)
+  print(fmt(tabf2, "Global", uniq_g, decl_g, token_g, size_g, avg(token_g, size_g)))
+  print(hl)
+  print(fmt(tabf2, "Local (in)", uniq_li, decl_li, token_li, size_li, avg(token_li, size_li)))
+  print(fmt(tabf2, "TOTAL (in)", uniq_ti, decl_ti, token_ti, size_ti, avg(token_ti, size_ti)))
+  print(hl)
+  print(fmt(tabf2, "Local (out)", uniq_lo, decl_lo, token_lo, size_lo, avg(token_lo, size_lo)))
+  print(fmt(tabf2, "TOTAL (out)", uniq_to, decl_to, token_to, size_to, avg(token_to, size_to)))
+  print(hl.."\n")
+end
+
+----------------------------------------------------------------------
+-- main entry point
+-- * does only local variable optimization for now
+----------------------------------------------------------------------
+
+function optimize(option, _toklist, _seminfolist, _globalinfo, _localinfo)
+  -- set tables
+  toklist, seminfolist, globalinfo, localinfo
+    = _toklist, _seminfolist, _globalinfo, _localinfo
+  var_new = 0                           -- reset variable name allocator
+  varlist = {}
+  ------------------------------------------------------------------
+  -- preprocess global/local tables, handle entropy reduction
+  ------------------------------------------------------------------
+  globaluniq = preprocess(globalinfo)
+  localuniq = preprocess(localinfo)
+  if option["opt-entropy"] then         -- for entropy improvement
+    recalc_for_entropy(option)
+  end
+  ------------------------------------------------------------------
+  -- build initial declared object table, then sort according to
+  -- token count, this might help assign more tokens to more common
+  -- variable names such as 'e' thus possibly reducing entropy
+  -- * an object knows its localinfo index via its 'id' field
+  -- * special handling for "self" special local (parameter) here
+  ------------------------------------------------------------------
+  local object = {}
+  for i = 1, #localinfo do
+    object[i] = localinfo[i]
+  end
+  table.sort(object,                    -- sort largest first
+    function(v1, v2)
+      return v1.xcount > v2.xcount
+    end
+  )
+  ------------------------------------------------------------------
+  -- the special "self" function parameters must be preserved
+  -- * the allocator below will never use "self", so it is safe to
+  --   keep those implicit declarations as-is
+  ------------------------------------------------------------------
+  local temp, j, gotself = {}, 1, false
+  for i = 1, #object do
+    local obj = object[i]
+    if not obj.isself then
+      temp[j] = obj
+      j = j + 1
+    else
+      gotself = true
+    end
+  end
+  object = temp
+  ------------------------------------------------------------------
+  -- a simple first-come first-served heuristic name allocator,
+  -- note that this is in no way optimal...
+  -- * each object is a local variable declaration plus existence
+  -- * the aim is to assign short names to as many tokens as possible,
+  --   so the following tries to maximize name reuse
+  -- * note that we preserve sort order
+  ------------------------------------------------------------------
+  local nobject = #object
+  while nobject > 0 do
+    local varname, gcollide
+    repeat
+      varname, gcollide = new_var_name()  -- collect a variable name
+    until not SKIP_NAME[varname]          -- skip all special names
+    varlist[#varlist + 1] = varname       -- keep a list
+    local oleft = nobject
+    ------------------------------------------------------------------
+    -- if variable name collides with an existing global, the name
+    -- cannot be used by a local when the name is accessed as a global
+    -- during which the local is alive (between 'act' to 'rem'), so
+    -- we drop objects that collides with the corresponding global
+    ------------------------------------------------------------------
+    if gcollide then
+      -- find the xref table of the global
+      local gref = globalinfo[globaluniq[varname].id].xref
+      local ngref = #gref
+      -- enumerate for all current objects; all are valid at this point
+      for i = 1, nobject do
+        local obj = object[i]
+        local act, rem = obj.act, obj.rem  -- 'live' range of local
+        -- if rem < 0, it is a -id to a local that had the same name
+        -- so follow rem to extend it; does this make sense?
+        while rem < 0 do
+          rem = localinfo[-rem].rem
+        end
+        local drop
+        for j = 1, ngref do
+          local p = gref[j]
+          if p >= act and p <= rem then drop = true end  -- in range?
+        end
+        if drop then
+          obj.skip = true
+          oleft = oleft - 1
+        end
+      end--for
+    end--if gcollide
+    ------------------------------------------------------------------
+    -- now the first unassigned local (since it's sorted) will be the
+    -- one with the most tokens to rename, so we set this one and then
+    -- eliminate all others that collides, then any locals that left
+    -- can then reuse the same variable name; this is repeated until
+    -- all local declaration that can use this name is assigned
+    -- * the criteria for local-local reuse/collision is:
+    --   A is the local with a name already assigned
+    --   B is the unassigned local under consideration
+    --   => anytime A is accessed, it cannot be when B is 'live'
+    --   => to speed up things, we have first/last accesses noted
+    ------------------------------------------------------------------
+    while oleft > 0 do
+      local i = 1
+      while object[i].skip do  -- scan for first object
+        i = i + 1
+      end
+      ------------------------------------------------------------------
+      -- first object is free for assignment of the variable name
+      -- [first,last] gives the access range for collision checking
+      ------------------------------------------------------------------
+      oleft = oleft - 1
+      local obja = object[i]
+      i = i + 1
+      obja.newname = varname
+      obja.skip = true
+      obja.done = true
+      local first, last = obja.first, obja.last
+      local xref = obja.xref
+      ------------------------------------------------------------------
+      -- then, scan all the rest and drop those colliding
+      -- if A was never accessed then it'll never collide with anything
+      -- otherwise trivial skip if:
+      -- * B was activated after A's last access (last < act)
+      -- * B was removed before A's first access (first > rem)
+      -- if not, see detailed skip below...
+      ------------------------------------------------------------------
+      if first and oleft > 0 then  -- must have at least 1 access
+        local scanleft = oleft
+        while scanleft > 0 do
+          while object[i].skip do  -- next valid object
+            i = i + 1
+          end
+          scanleft = scanleft - 1
+          local objb = object[i]
+          i = i + 1
+          local act, rem = objb.act, objb.rem  -- live range of B
+          -- if rem < 0, extend range of rem thru' following local
+          while rem < 0 do
+            rem = localinfo[-rem].rem
+          end
+          --------------------------------------------------------
+          if not(last < act or first > rem) then  -- possible collision
+            --------------------------------------------------------
+            -- B is activated later than A or at the same statement,
+            -- this means for no collision, A cannot be accessed when B
+            -- is alive, since B overrides A (or is a peer)
+            --------------------------------------------------------
+            if act >= obja.act then
+              for j = 1, obja.xcount do  -- ... then check every access
+                local p = xref[j]
+                if p >= act and p <= rem then  -- A accessed when B live!
+                  oleft = oleft - 1
+                  objb.skip = true
+                  break
+                end
+              end--for
+            --------------------------------------------------------
+            -- A is activated later than B, this means for no collision,
+            -- A's access is okay since it overrides B, but B's last
+            -- access need to be earlier than A's activation time
+            --------------------------------------------------------
+            else
+              if objb.last and objb.last >= obja.act then
+                oleft = oleft - 1
+                objb.skip = true
+              end
+            end
+          end
+          --------------------------------------------------------
+          if oleft == 0 then break end
+        end
+      end--if first
+      ------------------------------------------------------------------
+    end--while
+    ------------------------------------------------------------------
+    -- after assigning all possible locals to one variable name, the
+    -- unassigned locals/objects have the skip field reset and the table
+    -- is compacted, to hopefully reduce iteration time
+    ------------------------------------------------------------------
+    local temp, j = {}, 1
+    for i = 1, nobject do
+      local obj = object[i]
+      if not obj.done then
+        obj.skip = false
+        temp[j] = obj
+        j = j + 1
+      end
+    end
+    object = temp  -- new compacted object table
+    nobject = #object  -- objects left to process
+    ------------------------------------------------------------------
+  end--while
+  ------------------------------------------------------------------
+  -- after assigning all locals with new variable names, we can
+  -- patch in the new names, and reprocess to get 'after' stats
+  ------------------------------------------------------------------
+  for i = 1, #localinfo do  -- enumerate all locals
+    local obj = localinfo[i]
+    local xref = obj.xref
+    if obj.newname then                 -- if got new name, patch it in
+      for j = 1, obj.xcount do
+        local p = xref[j]               -- xrefs indexes the token list
+        seminfolist[p] = obj.newname
+      end
+      obj.name, obj.oldname             -- adjust names
+        = obj.newname, obj.name
+    else
+      obj.oldname = obj.name            -- for cases like 'self'
+    end
+  end
+  ------------------------------------------------------------------
+  -- deal with statistics output
+  ------------------------------------------------------------------
+  if gotself then  -- add 'self' to end of list
+    varlist[#varlist + 1] = "self"
+  end
+  local afteruniq = preprocess(localinfo)
+  stats_summary(globaluniq, localuniq, afteruniq, option)
+  ------------------------------------------------------------------
+end