-- LunaCON CON to Lunatic translator
-- requires LPeg, http://www.inf.puc-rio.br/~roberto/lpeg/lpeg.html

local require = require
local lpeg = require("lpeg")

local bit
local math = require("math")
local string = require("string")
local table = require("table")


local arg = arg

local assert = assert
local ipairs = ipairs
local loadstring = loadstring
local pairs = pairs
local pcall = pcall
local print = print
local tonumber = tonumber
local tostring = tostring
local type = type
local unpack = unpack

-- non-nil if running from EDuke32
-- (read_into_string~=nil  iff  string.dump==nil)
local read_into_string = read_into_string
local ffi, ffiC

if (string.dump) then
    bit = require("bit")
    require("strict")
else
    bit = require("bit")
    ffi = require("ffi")
    ffiC = ffi.C
end


module("lunacon")


-- I think that the "too many pending calls/choices" is unavoidable in general.
-- This limit is of course still arbitrary, but writing long if/else cascades
-- in CON isn't pretty either (though sometimes necessary because nested switches
-- don't work?)
-- See also:  http://lua-users.org/lists/lua-l/2010-03/msg00086.html
lpeg.setmaxstack(1024);


local Pat, Set, Range, Var = lpeg.P, lpeg.S, lpeg.R, lpeg.V
local POS = lpeg.Cp

-- CON language definitions (among other things, all keywords pattern).
local conl = require("con_lang")


local function match_until(matchsp, untilsp)  -- (!untilsp matchsp)* in PEG
    -- sp: string or pattern
    return (matchsp - Pat(untilsp))^0
end

local format = string.format

local function printf(fmt, ...)
    print(format(fmt, ...))
end


---=== semantic action functions ===---

local inf = 1/0
local NaN = 0/0

-- Last keyword position, for error diagnosis.
local g_lastkwpos = nil
local g_lastkw = nil
local g_badids = {}  -- maps bad id strings to 'true'

local g_recurslevel = -1  -- 0: base CON file, >0 included
local g_filename = "???"
local g_directory = ""  -- with trailing slash if not empty
local g_maxerrors = 20
local g_numerrors = 0

-- Default directory to search for GAME.CON etc.
-- Stand-alone LunaCON only.
local g_defaultDir = nil

-- Warning options. Key names are the same as cmdline options, e.g.
-- -Wno-bad-identifier for disabling the "bad identifier" warning.
local g_warn = { ["not-redefined"]=true, ["bad-identifier"]=true,
                 ["number-conversion"]=true, ["system-gamevar"]=true, }

-- Code generation options.
local g_cgopt = { ["no"]=false, }

-- How many 'if' statements are following immediately each other,
-- needed to cope with CONs dangling-else resolution
local g_iflevel = 0
local g_ifelselevel = 0

---=== Code generation ===---
local GVFLAG = {
    PERPLAYER=1, PERACTOR=2, PERX_MASK=3,
    SYSTEM   = 0x00000800,
    READONLY = 0x00001000,

    NODEFAULT = 0x00000400,  -- don't reset on actor spawn
    NORESET   = 0x00020000,  -- don't reset when restoring map state
}

-- NOTE: This differs from enum GamevarFlags_t's GAMEVAR_USER_MASK
GVFLAG.USER_MASK = GVFLAG.PERX_MASK + GVFLAG.NODEFAULT + GVFLAG.NORESET

-- CON --> mangled Lua function name, also existence check:
local g_funcname = {}
-- while parsing a block, it is a table of "gencode" tables:
local g_switchCode = nil
-- Global number of switch statements:
local g_switchCount = 0
-- [identifier] = { name=<mangled name / code>, flags=<gamevar flags> }
local g_gamevar = {}
-- [identifier] = { name=<mangled name / code>, size=<initial size> }
local g_gamearray = {}

local g_have_file = {}  -- [filename]=true
local g_curcode = nil  -- a table of string pieces or other "gencode" tables

-- will be a table, see reset_codegen()
local g_code = nil


local function ACS(s) return "actor[_aci]"..s end
local function SPS(s) return "sprite[_aci]"..s end
local function PLS(s) return "player[_pli]"..s end


local function getlinecol(pos) end -- fwd-decl

local function new_initial_codetab()
    return {
        "local _con, _bit, _math = require'con', require'bit', require'math';",
        "local _xmath, _geom = require'xmath', require'geom';",
        "local sector, sprite, actor, player = sector, sprite, actor, player;",
        "local gameactor, gameevent, _gv = gameactor, gameevent, gv;",
        "local updatesector, updatesectorz, cansee = updatesector, updatesectorz, cansee;",
        "local print = print;",

        -- switch function table, indexed by global switch sequence number:
        "local _SW = {};",
        -- CON "states" (subroutines), gamevars and gamearrays (see mangle_name())
        "local _F,_V,_A={},{},{};"
           }
end

-- CON global system gamevar
local function CSV(var) return "_gv._csv"..var end

-- Creates the table of predefined game variables.
-- KEEPINSYNC gamevars.c: Gv_AddSystemVars()
local function new_initial_gvartab()
    local wmembers = conl.wdata_members
    local MAX_WEAPONS = ffiC and ffiC.MAX_WEAPONS or 12

    local function GamevarCreationFunc(addflags)
        return function(varname)
            return { name=varname, flags=GVFLAG.SYSTEM+addflags }
        end
    end

    local RW = GamevarCreationFunc(0)
    local RO = GamevarCreationFunc(GVFLAG.READONLY)
    local PRW = GamevarCreationFunc(GVFLAG.PERPLAYER)
    local PRO = GamevarCreationFunc(GVFLAG.READONLY+GVFLAG.PERPLAYER)

    local gamevar = {
        -- NOTE: THISACTOR can mean different things in some contexts.
        THISACTOR = RO "_aci",

        RETURN = RW(CSV".RETURN"),
        HITAG = RW(CSV".HITAG"),
        LOTAG = RW(CSV".LOTAG"),
        TEXTURE = RW(CSV".TEXTURE"),

        xdim = RO "_gv.xdim",
        ydim = RO "_gv.ydim",
        windowx1 = RO "_gv.windowx1",
        windowy1 = RO "_gv.windowy1",
        windowx2 = RO "_gv.windowx2",
        windowy2 = RO "_gv.windowy2",

        yxaspect = RO "_gv._get_yxaspect()",
        viewingrange = RO "_gv._get_viewingrange()",

        numsectors = RO "_gv.numsectors",
        NUMSECTORS = RO "_gv.numsectors",
        NUMWALLS = RO "_gv.numwalls",

        randomseed = RW "_gv.randomseed",
        totalclock = RO "_gv.totalclock",
        framerate = RO "_gv._currentFramerate()",
        current_menu = RO "_gv._currentMenu()",
        rendmode = RO "_gv.currentRenderMode()",

        screenpeek = RO "_gv.screenpeek",

        camerax = RW "_gv.cam.pos.x",
        cameray = RW "_gv.cam.pos.y",
        cameraz = RW "_gv.cam.pos.z",
        cameraang = RW "_gv.cam.ang",
        camerahoriz = RW "_gv.cam.horiz",
        camerasect = RW "_gv.cam.sect",
        cameradist = RW "_gv.cam.dist",
        cameraclock = RW "_gv.cam.clock",

        -- HUD weapon gamevars
        currentweapon = RW "_gv.hudweap.cur",
        weaponcount = RW "_gv.hudweap.count",
        weapon_xoffset = RW "_gv.hudweap.gunposx",
        looking_angSR1 = RW "_gv.hudweap.lookhalfang",
        gun_pos = RW "_gv.hudweap.gunposy",
        looking_arc = RW "_gv.hudweap.lookhoriz",
        gs = RW "_gv.hudweap.shade",

        -- Some per-player gamevars
        ZRANGE = PRW(PLS".zrange"),
        ANGRANGE = PRW(PLS".angrange"),
        AUTOAIMANGLE = PRW(PLS".autoaimang"),

        PIPEBOMB_CONTROL = PRW(PLS".pipebombControl"),
        GRENADE_LIFETIME = PRW(PLS".pipebombLifetime"),
        GRENADE_LIFETIME_VAR = PRW(PLS".pipebombLifetimeVar"),
        TRIPBOMB_CONTROL = PRW(PLS".tripbombControl"),
        STICKYBOMB_LIFETIME = PRW(PLS".tripbombLifetime"),
        STICKYBOMB_LIFETIME_VAR = PRW(PLS".tripbombLifetimeVar"),

        -- These are not 100% authentic (they're only updated in certain
        -- circumstances, see player.c: P_SetWeaponGamevars()). But IMO it's
        -- more useful like this.
        WEAPON = PRO(PLS".curr_weapon"),
        WORKSLIKE = PRO(format(PLS".weapon[%s].workslike", PLS".curr_weapon")),

        VOLUME = RO "_gv.currentEpisode()",
        LEVEL = RO "_gv.currentLevel()",
    }

    for w=0,MAX_WEAPONS-1 do
        for i=1,#wmembers do
            local member = wmembers[i]:gsub(".* ","")  -- strip e.g. "int32_t "
            local name = format("WEAPON%d_%s", w, member:upper())
            gamevar[name] = PRW(format(PLS".weapon[%d].%s", w, member))
        end
    end

    return gamevar
end

local function reset_codegen()
    g_funcname = {}
    g_switchCode = nil
    g_switchCount = 0
    g_gamevar = new_initial_gvartab()
    g_gamearray = {}

    g_have_file = {}
    g_curcode = new_initial_codetab()
    -- [{actor, event, actor}num]=gencode_table
    g_code = { actor={}, event={}, loadactor={} }

    g_recurslevel = -1
    g_numerrors = 0
end

local function addcode(x)
    assert(type(x)=="string" or type(x)=="table")
    g_curcode[#g_curcode+1] = x
end

local function addcodef(fmt, ...)
    addcode(format(fmt, ...))
end

local function add_code_and_end(codetab, endstr)
    assert(type(codetab)=="table")
    addcode(codetab)
    addcode(endstr)
end

local function warnprintf() end  -- fwd-decl

local on = {}

function on.actor_end(usertype, tsamm, codetab)
    local tilenum = tsamm[1]

    local str = ""
    for i=2,math.min(#tsamm,4) do
        if ((i==3 or i==4) and tsamm[i]=="0") then
            -- HACK, gameactor() currently doesn't support literals
            tsamm[i] = "'NO'"
        end
        str = str .. tostring(tsamm[i])..","
    end
    if (#tsamm==5) then
        local flags = bit.bor(unpack(tsamm, 5))
        str = str .. flags..","
    end

    -- TODO: usertype (is non-nil only for 'useractor')
    addcodef("gameactor(%d,%sfunction(_aci, _pli, _dist)", tilenum, str)
    add_code_and_end(codetab, "end)")

    if (g_code.actor[tilenum] ~= nil) then
        -- XXX: position will be that of last command in actor code
        warnprintf("redefined actor %d", tilenum)
    end
    g_code.actor[tilenum] = codetab
end

local BAD_ID_CHARS0 = "_/\\*?"  -- allowed 1st identifier chars
local BAD_ID_CHARS1 = "_/\\*-+?"  -- allowed following identifier chars

-- Return the Lua code by which the CON object <name> is referenced in the
-- translated code.
local function mangle_name(name, prefix)
    return format("_%s[%q]", prefix, name)
end

function on.state_begin_Cmt(_subj, _pos, statename)
    -- We must register the state name early (Cmt) because otherwise, it won't
    -- be found in a recursive state. XXX: The real issue seems to be the use
    -- of "Cmt"s in other places, which messes up the sequence of running the
    -- semantic actions.
    local ourname = mangle_name(statename, "F")
    g_funcname[statename] = ourname
    return true, ourname
end

function on.state_end(funcname, codetab)
    addcodef("%s=function(_aci, _pli, _dist)", funcname)
    add_code_and_end(codetab, "end")
end

function on.event_end(eventidx, codetab)
    addcodef("gameevent(%d, function (_aci, _pli, _dist)", eventidx)
    add_code_and_end(codetab, "end)")

    g_code.event[eventidx] = codetab
end

function on.eventloadactor_end(tilenum, codetab)
    -- Translate eventloadactor into a chained EVENT_LOADACTOR block
    addcode("gameevent('LOADACTOR', function (_aci, _pli, _dist)")
    addcodef("if (%s==%d) then", SPS".picnum", tilenum)
    addcode(codetab)
    addcode("end")
    addcode("end)")

    if (g_code.loadactor[tilenum] ~= nil) then
        warnprintf("redefined loadactor %d", tilenum)
    end
    g_code.loadactor[tilenum] = codetab
end

----------

local function linecolstr(pos)
    local line, col = getlinecol(pos)
    return format("%d:%d", line, col)
end

local function increment_numerrors()
    g_numerrors = g_numerrors+1
    if (g_numerrors == g_maxerrors) then
        g_numerrors = inf
        printf("Too many errors (%d), aborting...", g_maxerrors)
    end
end

local function perrprintf(pos, fmt, ...)
    printf("%s %s: error: "..fmt, g_filename, linecolstr(pos), ...)
    increment_numerrors()
end

local function errprintf(fmt, ...)
    if (g_lastkwpos) then
        perrprintf(g_lastkwpos, fmt, ...)
    else
        printf("%s ???: error: "..fmt, g_filename, ...)
        increment_numerrors()
    end
end

local function pwarnprintf(pos, fmt, ...)
    printf("%s %s: warning: "..fmt, g_filename, linecolstr(pos), ...)
end

function warnprintf(fmt, ...)  -- local
    if (g_lastkwpos) then
        pwarnprintf(g_lastkwpos, fmt, ...)
    else
        printf("%s ???: warning: "..fmt, g_filename, ...)
    end
end

local function parse_number(pos, numstr)
    local num = tonumber((numstr:gsub("h$", "")))

    -- num==nil for Rio Lua, which doesn't handle large hex literals.
    if (num==nil or not (num >= -0x80000000 and num <= 0xffffffff)) then
        perrprintf(pos, "number %s out of the range of a 32-bit integer", numstr)
        -- Be careful not to write bound checks like
        -- "if (i<LOWBOUND or i>HIGHBOUND) then error('...') end":
        num = NaN
    elseif (num >= 0x80000000 and numstr:sub(1,2):lower()~="0x") then
        if (g_warn["number-conversion"]) then
            pwarnprintf(pos, "number %s converted to a negative one", numstr)
        end
        num = num-(0xffffffff+1)
    end

    return num
end

-- returns: OK?
local function check_tilenum(tilenum)
    if (not (tilenum >= 0 and tilenum < (ffiC and ffiC.MAXTILES or 30720))) then
        errprintf("invalid tile number %d", tilenum)
        return false
    end

    return true
end


-- Mapping of various "define" types to the respective number of members and
-- vice versa
local LABEL = { MOVE=2, AI=3, ACTION=5, [2]="move", [3]="ai", [5]="action",
                NUMBER=1, [1]="number" }

-- Function names in the 'con' module
local LABEL_FUNCNAME = { [2]="move", [3]="ai", [5]="action" }

local g_labeldef = {}  -- Lua numbers for numbers, strings for composites
local g_labeltype = {}

local function reset_labels()
    g_badids = {}

    -- NO is also a valid `move', `ai' or `action', but they are handled
    -- separately in lookup.composite().
    g_labeldef = {
        NO = 0,
        -- NOTE: these are read-only gamevars in C-CON
        CLIPMASK0 = 65536+1,  -- blocking
        CLIPMASK1 = (256*65536)+64,  -- hittable
        -- TODO...?
        COOP = 0,
        MULTIMODE = 0,
        numplayers = 1,
        myconnectindex = 0,
    }

    for varname,_ in pairs(g_labeldef) do
        g_labeltype[varname] = LABEL.NUMBER
    end

    -- Initialize default defines.
    for i=1,#conl.labels do
        for label, val in pairs(conl.labels[i]) do
            g_labeldef[label] = val
            g_labeltype[label] = LABEL.NUMBER
        end
    end
end

-- Table of functions doing various lookups (label, gamevar, ...)
local lookup = {}

function lookup.defined_label(pos, maybe_minus_str, identifier)
    local num = g_labeldef[identifier]

    if (num == nil) then
        perrprintf(pos, "label \"%s\" is not defined", identifier)
        return -inf  -- return a number for type cleanness
    end

    if (g_labeltype[identifier] ~= LABEL.NUMBER) then
        perrprintf(pos, "label \"%s\" is not a `define'd number", identifier)
        return -inf
    end

    assert(type(num)=="number")

    return (maybe_minus_str=="" and 1 or -1) * num
end

local function check_sysvar_def_attempt(identifier)
    if (identifier=="actorvar") then
        errprintf("cannot define reserved symbol `actorvar'")
        return true
    end
end

local function do_define_label(identifier, num)
    if (check_sysvar_def_attempt(identifier)) then
        return
    end

    local oldtype = g_labeltype[identifier]
    local oldval = g_labeldef[identifier]

    if (oldval) then
        if (oldtype ~= LABEL.NUMBER) then
            errprintf("refusing to overwrite `%s' label \"%s\" with a `define'd number",
                      LABEL[oldtype], identifier)
        else
            -- conl.labels[...]: don't warn for wrong PROJ_ redefinitions
            if (g_warn["not-redefined"]) then
                if (oldval ~= num and conl.PROJ[identifier]==nil) then
                    warnprintf("label \"%s\" not redefined with new value %d (old: %d)",
                               identifier, num, oldval)
                end
            end
        end
    else
        if (g_gamevar[identifier]) then
            warnprintf("symbol `%s' already used for game variable", identifier)
        end

        -- New definition of a label
        g_labeldef[identifier] = num
        g_labeltype[identifier] = LABEL.NUMBER
    end
end

local function check_composite_literal(labeltype, pos, num)
    if (num==0 or num==1) then
        return (num==0) and "0" or "1"
    else
        perrprintf(pos, "literal `%s' number must be either 0 or 1", LABEL[labeltype])
        return "_INVALIT"
    end
end

function lookup.composite(labeltype, pos, identifier)
    if (identifier=="NO") then
        -- NO is a special case and is valid for move, action and ai,
        -- being the same as passing a literal 0.
        return "0"
    end

    local val = g_labeldef[identifier]

    if (val == nil) then
        perrprintf(pos, "label \"%s\" is not defined", identifier)
        return "_NOTDEF"
    elseif (g_labeltype[identifier] ~= labeltype) then
        if (identifier=="randomangle" and labeltype==LABEL.MOVE) then
            pwarnprintf(pos, "label \"randomangle\" is not a `move' value, assuming 0")
            return "0"
        else
            perrprintf(pos, "label \"%s\" is not a%s `%s' value", identifier,
                       labeltype==LABEL.MOVE and "" or "n", LABEL[labeltype])
            return "_WRONGTYPE"
        end
    end

    -- Generate a quoted identifier name.
    val = format("%q", identifier)

    return val
end

local function do_define_composite(labeltype, identifier, ...)
    local oldtype = g_labeltype[identifier]
    local oldval = g_labeldef[identifier]

    if (oldval) then
        if (oldtype ~= labeltype) then
            errprintf("refusing to overwrite `%s' label \"%s\" with a `%s' value",
                      LABEL[oldtype], identifier, LABEL[labeltype])
        else
            warnprintf("duplicate `%s' definition of \"%s\" ignored",
                       LABEL[labeltype], identifier)
        end
        return
    end

    -- Fill up omitted arguments with zeros.
    local isai = (labeltype == LABEL.AI)
    local args = {...}
    for i=#args+1,labeltype do
        -- passing nil to con.ai will make the action/move the null one
        args[i] = (isai and i<=2) and "nil" or 0
    end

    if (isai) then
        assert(type(args[1])=="string")
        assert(type(args[2])=="string")

        -- OR together the flags
        for i=#args,LABEL.AI+1, -1 do
            -- TODO: check?
            args[LABEL.AI] = bit.bor(args[LABEL.AI], args[i])
            args[i] = nil
        end
    end

    -- Make a string out of that.
    for i=1+(isai and 2 or 0),#args do
        args[i] = format("%d", args[i])
    end

    addcodef("_con.%s(%q,%s)", LABEL_FUNCNAME[labeltype], identifier, table.concat(args, ","))

    g_labeldef[identifier] = ""
    g_labeltype[identifier] = labeltype
end


local function parse(contents) end -- fwd-decl

local function do_include_file(dirname, filename)
    assert(type(filename)=="string")

    if (g_have_file[filename] ~= nil) then
        printf("[%d] Fatal error: infinite loop including \"%s\"", filename)
        g_numerrors = inf
        return
    end

    local contents

    if (read_into_string) then
        -- running from EDuke32
        contents = read_into_string(filename)
    else
        -- running stand-alone
        local io = require("io")

        local fd, msg = io.open(dirname..filename)
        if (fd == nil) then
            -- strip up to and including first slash:
            filename = filename:gsub("^.-/", "")
            fd, msg = io.open(dirname..filename)

            -- As a last resort, try the "default directory"
            if (fd==nil and g_defaultDir) then
                -- strip up to and including last slash (if any):
                filename = filename:gsub("^.*/", "")
                fd, msg = io.open(g_defaultDir.."/"..filename)
            end

            if (fd == nil) then
                printf("[%d] Fatal error: couldn't open %s", g_recurslevel, msg)
                g_numerrors = inf
                return
            end
        end

        contents = fd:read("*all")
        fd:close()
    end

    if (contents == nil) then
        -- maybe that file name turned out to be a directory or other
        -- special file accidentally
        printf("[%d] Fatal error: couldn't read from \"%s\"",
               g_recurslevel, dirname..filename)
        g_numerrors = inf
        return
    end

    -- XXX: File name that's displayed here may not be the actual opened one
    -- (esp. for stand-alone version).
    printf("%s[%d] Translating file \"%s\"", (g_recurslevel==-1 and "\n---- ") or "",
           g_recurslevel+1, dirname..filename);

    local oldfilename = g_filename
    g_filename = filename
    parse(contents)
    g_filename = oldfilename
end

-- Table of various outer command handling functions.
local Cmd = {}

function Cmd.NYI(msg)
    return function()
        errprintf(msg.." not yet implemented")
    end
end

function Cmd.nyi(msg)
    return function()
        warnprintf(msg.." not yet implemented")
    end
end

function Cmd.include(filename)
    do_include_file(g_directory, filename)
end

--- Per-module game data
local g_data = {}
local EPMUL = conl.MAXLEVELS

local function reset_gamedata()
    g_data = {}

    -- [EPMUL*ep + lev] = { ptime=<num>, dtime=<num>, fn=<str>, name=<str> }
    g_data.level = {}
    -- [ep] = <str>
    g_data.volname = {}
    -- [skillnum] = <str>
    g_data.skillname = {}
    -- [quotenum] = <str>
    g_data.quote = {}
    -- table of length 26 or 30 containg numbers
    g_data.startup = {}
    -- [soundnum] = { fn=<str>, params=<table of length 5> }
    g_data.sound = {}
    -- [volnum] = <table of length numlevels (<= MAXLEVELS) of <str>>
    g_data.music = {}
end

function Cmd.definelevelname(vol, lev, fn, ptstr, dtstr, levname)
    if (not (vol >= 0 and vol < conl.MAXVOLUMES)) then
        errprintf("volume number exceeds maximum volume count.")
        return
    end

    if (not (lev >= 0 and lev < conl.MAXLEVELS)) then
        errprintf("level number exceeds maximum number of levels per episode.")
        return
    end

    -- TODO: Bcorrectfilename(fn)

    local function secs(tstr)
        local m, s = string.match(tstr, ".+:.+")
        m, s = tonumber(m), tonumber(s)
        return (m and s) and m*60+s or 0
    end

    local map = {
        ptime=secs(ptstr), dtime=secs(dtstr), fn="/"..fn, name=levname
    }

    if (ffi) then
        ffiC.C_DefineLevelName(vol, lev, map.fn, map.ptime, map.dtime, map.name)
    end

    g_data.level[EPMUL*vol+lev] = map
end

local function defineXname(what, ffiCfuncname, X, name)
    name = name:upper()
    if (ffi) then
        ffiC[ffiCfuncname](X, name)
        if (#name > 32) then
            warnprintf("%s %d name truncated to 32 characters.", what, X)
        end
    end
    return name
end

function Cmd.defineskillname(skillnum, name)
    if (not (skillnum >= 0 and skillnum < conl.MAXSKILLS)) then
        errprintf("skill number is negative or exceeds maximum skill count.")
        return
    end

    name = defineXname("skill", "C_DefineSkillName", skillnum, name)
    g_data.skillname[skillnum] = name
end

function Cmd.definevolumename(vol, name)
    if (not (vol >= 0 and vol < conl.MAXVOLUMES)) then
        errprintf("volume number is negative or exceeds maximum volume count.")
        return
    end

    name = defineXname("volume", "C_DefineVolumeName", vol, name)
    g_data.volname[vol] = name
end

function Cmd.definegamefuncname(idx, name)
    local NUMGAMEFUNCTIONS = (ffi and ffiC.NUMGAMEFUNCTIONS or 56)
    if (not (idx >= 0 and idx < NUMGAMEFUNCTIONS)) then
        errprintf("function number exceeds number of game functions.")
        return
    end

    assert(type(name)=="string")
    -- XXX: in place of C-CON's "invalid character in function name" report:
    name:gsub("[^A-Za-z0-9]", "_")

    if (ffi) then
        ffiC.C_DefineGameFuncName(idx, name)
    end
end

-- strip whitespace from front and back
local function stripws(str)
    return str:match("^%s*(.*)%s*$")
end

function Cmd.definequote(qnum, quotestr)
    if (not (qnum >= 0 and qnum < conl.MAXQUOTES)) then
        errprintf("quote number is negative or exceeds limit of %d.", conl.MAXQUOTES-1)
        return
    end

    quotestr = stripws(quotestr)

    if (#quotestr >= conl.MAXQUOTELEN) then
        -- NOTE: Actually, C_DefineQuote takes care of this! That is,
        -- standalone, the string isn't truncated.
        warnprintf("quote %d truncated to %d characters.", qnum, conl.MAXQUOTELEN-1)
    end

    if (ffi) then
        ffiC.C_DefineQuote(qnum, quotestr)
    end

    g_data.quote[qnum] = quotestr
end

function Cmd.defineprojectile(tilenum, what, val)
    local ok = check_tilenum(tilenum)

    if (ffi and ok) then
        -- TODO: potentially bound-check some members?
        ffiC.C_DefineProjectile(tilenum, what, val)
    end
end

-- flags: if string, look up in ffiC and OR, else set number directly.
function Cmd.xspriteflags(tilenum, flags)
    local ok = check_tilenum(tilenum)

    if (ffi and ok) then
        if (type(flags)=="number") then
            ffiC.g_tile[tilenum].flags = flags
        else
            assert(type(flags)=="string")
            ffiC.g_tile[tilenum].flags = bit.bor(ffiC.g_tile[tilenum].flags, ffiC[flags])
        end
    end
end

function Cmd.cheatkeys(sc1, sc2)
    if (ffi) then
        ffiC.CheatKeys[0] = sc1
        ffiC.CheatKeys[1] = sc2
    end
end

function Cmd.setdefname(filename)
    assert(type(filename)=="string")
    if (ffi) then
        if (ffiC.C_SetDefName(filename) ~= 0) then
            error("OUT OF MEMORY", 0)
        end
    end
end

function Cmd.gamestartup(...)
    local args = {...}

    if (#args ~= 26 and #args ~= 30) then
        errprintf("must pass either 26 (1.3D) or 30 (1.5) values")
        return
    end

    if (ffi) then
        -- running from EDuke32
        if (#args == 30) then
            ffiC.g_scriptVersion = 14
        end
        local params = ffi.new("int32_t [30]", args)
        ffiC.G_DoGameStartup(params)
    end

    g_data.startup = args  -- TODO: sanity-check them
end

function Cmd.definesound(sndnum, fn, ...)
    if (not (sndnum >= 0 and sndnum < conl.MAXSOUNDS)) then
        errprintf("sound number is negative or exceeds sound limit of %d", conl.MAXSOUNDS-1)
        return
    end

    local params = {...}  -- TODO: sanity-check them
    if (ffi) then
        local cparams = ffi.new("int32_t [5]", params)
        assert(type(fn)=="string")
        ffiC.C_DefineSound(sndnum, fn, cparams)
    end

    g_data.sound[sndnum] = { fn=fn, params=params }
end

function Cmd.music(volnum, ...)
    if (not (volnum >= 0 and volnum < conl.MAXVOLUMES+1)) then
        -- NOTE: MAXVOLUMES is OK, since it's MapInfo[(MAXVOLUMES+1)*MAXLEVELS]
        errprintf("volume number is negative or exceeds MAXVOLUMES=%d", conl.MAXVOLUMES)
        return
    end

    local filenames = {...}

    if (#filenames > conl.MAXLEVELS) then
        warnprintf("ignoring extraneous %d music file names", #filenames-conl.MAXLEVELS)
        for i=conl.MAXLEVELS+1,#filenames do
            filenames[i] = nil
        end
    end

    if (ffi) then
        for i=1,#filenames do
            assert(type(filenames[i])=="string")
            ffiC.C_DefineMusic(volnum, i-1, "/"..filenames[i])
        end
    end

    g_data.music[volnum] = filenames
end


--- GAMEVARS / GAMEARRAYS

function Cmd.gamearray(identifier, initsize)
    if (check_sysvar_def_attempt(identifier)) then
        return
    end

    if (initsize >= 0x7fffffff+0ULL) then
        errprintf("invalid initial size %d for gamearray `%s'", initsize, identifier)
        return
    end

    local oga = g_gamearray[identifier]
    if (oga) then
        if (initsize ~= oga.size) then
            errprintf("duplicate gamearray definition `%s' has different size", identifier)
            return
        else
            warnprintf("duplicate gamearray definition `%s' ignored", identifier)
            return
        end
    end

    if (g_gamevar[identifier]) then
        warnprintf("symbol `%s' already used for game variable", identifier)
    end

    local ga = { name=mangle_name(identifier, "A"), size=initsize }
    g_gamearray[identifier] = ga

    addcodef("%s=_con._gamearray(%d)", ga.name, initsize)
end

function Cmd.gamevar(identifier, initval, flags)
    if (check_sysvar_def_attempt(identifier)) then
        return
    end

    -- TODO: handle user bits like NORESET or NODEFAULT
    if (bit.band(flags, bit.bnot(GVFLAG.USER_MASK)) ~= 0) then
        -- TODO: a couple of the presumably safe ones
        errprintf("gamevar flags other than 1, 2, 1024 or 131072: NYI or forbidden")
        return
    end

    if (flags==GVFLAG.PERPLAYER+GVFLAG.PERACTOR) then
        errprintf("invalid gamevar flags: must be either PERPLAYER or PERACTOR, not both")
        return
    end

    local ogv = g_gamevar[identifier]

    if (ogv ~= nil) then
        local oflags = ogv.flags
        if (oflags ~= flags) then
            if (bit.band(oflags, GVFLAG.SYSTEM) ~= 0) then
                -- Attempt to override a system gamevar. See if it's read-only...
                if (bit.band(oflags, GVFLAG.READONLY) ~= 0) then
                    errprintf("attempt to override read-only system gamevar `%s'", identifier)
                    return
                end

                local flagsnosys = bit.band(oflags, bit.bnot(GVFLAG.SYSTEM))
                if (flagsnosys ~= flags and g_warn["system-gamevar"]) then
                    warnprintf("overrode initial value of `%s', but kept "..
                               "flags (%d)", identifier, flagsnosys)
                end

                -- Emit code to set the variable at Lua parse time.
                if (bit.band(oflags, GVFLAG.PERPLAYER) ~= 0) then
                    -- Replace player index by 0.
                    -- TODO: init for all players.
                    local pvar, numrepls = ogv.name:gsub("_pli", "0")
                    assert(numrepls>=1)
                    addcodef("%s=%d", pvar, initval)
                else
                    addcodef("%s=%d", ogv.name, initval)
                end
                return
            end

            errprintf("duplicate gamevar definition `%s' has different flags", identifier)
            return
        else
            warnprintf("duplicate gamevar definition `%s' ignored", identifier)
            return
        end
    end

    local ltype = g_labeltype[identifier]
    if (ltype ~= nil) then
        warnprintf("symbol `%s' already used for a defined %s", identifier, LABEL[ltype])
    end

    local gv = { name=mangle_name(identifier, "V"), flags=flags }
    g_gamevar[identifier] = gv

    -- TODO: Write gamevar system on the Lunatic side and hook it up.
    -- TODO: per-player gamevars
    if (flags==GVFLAG.PERACTOR) then
        addcodef("%s=_con.peractorvar(%d)", gv.name, initval)
    else
        addcodef("%s=%d", gv.name, initval)
    end
end

function lookup.gamearray(identifier)
    local ga = g_gamearray[identifier]
    if (ga == nil) then
        errprintf("symbol `%s' is not a game array", identifier)
        return "_INVALIDGA"
    end
    return ga.name
end

-- <aorpvar>: code for actor or player index
function lookup.gamevar(identifier, aorpvar, writable)
    local gv = g_gamevar[identifier]

    if (gv == nil) then
        errprintf("symbol `%s' is not a game variable", identifier)
        return "_INVALIDGV"
    end

    if (writable and bit.band(gv.flags, GVFLAG.READONLY) ~= 0) then
        errprintf("variable `%s' is read-only", identifier)
        return "_READONLYGV"
    end

    if (bit.band(gv.flags, GVFLAG.PERACTOR)~=0) then
        return format("%s[%s]", gv.name, aorpvar)
    else
        return gv.name
    end
end

local function maybe_gamevar_Cmt(subj, pos, identifier)
    if (g_gamevar[identifier]) then
        return true, lookup.gamevar(identifier, "_aci", false)
    end
end


----==== patterns ====----

---- basic ones
-- Windows, *nix and Mac newlines all exist in the wild!
local newline = "\r"*Pat("\n")^-1 + "\n"
local EOF = Pat(-1)
local anychar = Pat(1)
-- comments
local comment = "/*" * match_until(anychar, "*/") * "*/"
local linecomment = "//" * match_until(anychar, newline)
local whitespace = Var("whitespace")
local sp0 = whitespace^0
-- This "WS+" pattern matches EOF too, so that a forgotten newline at EOF is
-- properly handled
local sp1 = whitespace^1 + EOF
local alpha = Range("AZ", "az")  -- locale?
local alphanum = alpha + Range("09")
--local alnumtok = alphanum + Set("{}/\\*-_.")  -- see isaltok() in gamedef.c

--- Basic lexical elements ("tokens"). See the final grammar ("Grammar") for
--- their definitions.
local tok =
{
    maybe_minus = (Pat("-") * sp0)^-1,
    number = Var("t_number"),

    -- Valid identifier names are disjunct from keywords!
    -- XXX: CON is more permissive with identifier name characters:
    identifier = Var("t_identifier"),
    -- This one matches keywords, too:
    identifier_all = Var("t_identifier_all"),
    define = Var("t_define"),
    move = Var("t_move"),
    ai = Var("t_ai"),
    action = Var("t_action"),

    -- NOTE: no chance to whitespace and double quotes in filenames:
    filename = lpeg.C((anychar-Set(" \t\r\n\""))^1),
    newline_term_str = match_until(anychar, newline),

    rvar = Var("t_rvar"),
    wvar = Var("t_wvar"),
    gamearray = Var("t_gamearray"),

    -- for definelevelname
    time = lpeg.C(alphanum*alphanum^-1*":"*alphanum*alphanum^-1),

    state_ends = Pat("ends")
        + POS() * "else" * sp1 * "ends"
        / function(pos) pwarnprintf(pos, "stray `else' at end of state") end,
}


---- helper patterns / pattern constructing functions
local maybe_quoted_filename = ('"' * tok.filename * '"' + tok.filename)
-- empty string is handled too; we must not eat the newline then!
local newline_term_string = (#newline + EOF)*lpeg.Cc("")
    + (whitespace-newline)^1 * lpeg.C(tok.newline_term_str)


-- (sp1 * tok.define) repeated exactly n times
local function n_defines(n)  -- works well only for small n
    local pat = Pat(true)
    for i=1,n do
        pat = sp1 * tok.define * pat
    end
    return pat
end


local D, R, W, I, GARI, AC, MV, AI = -1, -2, -3, -4, -5, -6, -7, -8
local TOKEN_PATTERN = { [D]=tok.define, [R]=tok.rvar, [W]=tok.wvar,
                        [I]=tok.identifier, [GARI]=tok.gamearray,
                        [AC]=tok.action, [MV]=tok.move, [AI]=tok.ai }

-- Generic command pattern, types given by varargs.
-- The command name to be matched is attached later.
-- Example:
--  "command" writtenvar readvar def def:  gencmd(W,R,D,D)
--    -->  sp1 * tok.wvar * sp1 * tok.rvar * sp1 * tok.define * sp1 * tok.define
--  "command_with_no_args":  gencmd()
--    --> Pat(true)
local function cmd(...)
    local pat = Pat(true)
    local vartypes = {...}

    for i=1,#vartypes do
        pat = pat * sp1 * assert(TOKEN_PATTERN[vartypes[i]])
    end

    return pat
end


-- The command names will be attached to the front of the patterns later!

--== Top level CON commands ==--
-- XXX: many of these are also allowed inside actors/states/events in CON.
local Couter = {
    --- 1. Preprocessor
    include = sp1 * maybe_quoted_filename
        / Cmd.include,
    includedefault = cmd()
        / Cmd.NYI("`includedefault'"),
    define = cmd(I,D)
        / do_define_label,

    --- 2. Defines and Meta-Settings
    dynamicremap = cmd()
        / Cmd.NYI("dynamic tile remapping"),
    setcfgname = sp1 * tok.filename
        / Cmd.nyi("`setcfgname'"),
    setdefname = sp1 * tok.filename
        / Cmd.setdefname,
    setgamename = newline_term_string
        / Cmd.nyi("`setgamename'"),

    precache = cmd(D,D,D)
        , -- / Cmd.nyi("`precache'"),
    scriptsize = cmd(D)
        / "",  -- no-op
    cheatkeys = cmd(D,D)
        / Cmd.cheatkeys,

    definecheat = newline_term_string  -- XXX: actually tricker syntax (TS)
        , -- / Cmd.nyi("`definecheat'"),
    definegamefuncname = sp1 * tok.define * newline_term_string  -- XXX: TS?
        / Cmd.definegamefuncname,
    definegametype = n_defines(2) * newline_term_string
        / Cmd.NYI("`definegametype'"),  -- TODO_MP
    definelevelname = n_defines(2) * sp1 * tok.filename * sp1 * tok.time * sp1 * tok.time *
        newline_term_string
        / Cmd.definelevelname,
    defineskillname = sp1 * tok.define * newline_term_string
        / Cmd.defineskillname,
    definevolumename = sp1 * tok.define * newline_term_string
        / Cmd.definevolumename,

    definequote = sp1 * tok.define * newline_term_string
        / Cmd.definequote,
    defineprojectile = cmd(D,D,D)
        / Cmd.defineprojectile,
    definesound = sp1 * tok.define * sp1 * maybe_quoted_filename * n_defines(5)
        / Cmd.definesound,

    -- NOTE: gamevar.ogg and the like is OK, too
    music = sp1 * tok.define * match_until(sp1 * tok.filename, sp1 * conl.keyword * sp1)
        / Cmd.music,

    --- 3. Game Settings
    -- gamestartup has 26/30 fixed defines, depending on 1.3D/1.5 version:
    gamestartup = (sp1 * tok.define)^26
        / Cmd.gamestartup,
    spritenopal = cmd(D)
        / function(tilenum, flags) Cmd.xspriteflags(tilenum, "SFLAG_NOPAL") end,
    spritenoshade = cmd(D)
        / function(tilenum, flags) Cmd.xspriteflags(tilenum, "SFLAG_NOSHADE") end,
    spritenvg = cmd(D)
        / function(tilenum, flags) Cmd.xspriteflags(tilenum, "SFLAG_NVG") end,
    spriteshadow = cmd(D)
        / function(tilenum, flags) Cmd.xspriteflags(tilenum, "SFLAG_SHADOW") end,

    spriteflags = cmd(D,D)  -- also see inner
        / function(tilenum, flags) Cmd.xspriteflags(tilenum, flags) end,

    --- 4. Game Variables / Arrays
    gamevar = cmd(I,D,D)
        / Cmd.gamevar,
    gamearray = cmd(I,D)
        / Cmd.gamearray,

    --- 5. Top level commands that are also run-time commands
    move = sp1 * tok.identifier * (sp1 * tok.define)^-2  -- hvel, vvel
        / function(...) do_define_composite(LABEL.MOVE, ...) end,

    -- startframe, numframes, viewtype, incval, delay:
    action = sp1 * tok.identifier * (sp1 * tok.define)^-5
        / function(...) do_define_composite(LABEL.ACTION, ...) end,

    -- action, move, flags...:
    ai = sp1 * tok.identifier * (sp1 * tok.action *
                                 (sp1 * tok.move * (sp1 * tok.define)^0)^-1
                                )^-1
        / function(...) do_define_composite(LABEL.AI, ...) end,

    --- 6. Deprecated TLCs
    betaname = newline_term_string,
    enhanced = cmd(D),
}


--== Run time CON commands ==--
--- 1. Gamevar Operators
local varop = cmd(W,D)
local varvarop = cmd(W,R)

local function varopf(op)
    if (#op <= 2) then
        return varop / ("%1=%1"..op.."%2")
    else
        return varop / ("%1="..op.."(%1,%2)")
    end
end

local function varvaropf(op)
    if (#op <= 2) then
        return varvarop / ("%1=%1"..op.."%2")
    else
        return varvarop / ("%1="..op.."(%1,%2)")
    end
end

-- Allow nesting... stuff like
--   ifvarl actorvar[sprite[THISACTOR].owner].burning 0
-- is kinda breaking the classic "no array nesting" rules
-- (if there ever were any) but making our life harder else.
local arraypat = sp0 * "[" * sp0 * tok.rvar * sp0 * "]"

-- Have to bite the bullet here and list actor/player members with second
-- parameters, even though it's ugly to make it part of the syntax.  Also,
-- stuff like
--   actor[xxx].loogiex parm2 x
-- will be wrongly accepted at the parsing stage (loogiex is player's member)
-- because we don't discriminate between actor and player here.
local parm2memberpat = lpeg.C(Pat("htg_t") + "loogiex" + "loogiey" + "ammo_amount" +
                              "weaprecs" + "gotweapon" + "pals" + "max_ammo_amount") * sp1 * tok.rvar
-- The member name must match keywords, too (_all), because e.g. cstat is a member
-- of sprite[].
local bothmemberpat = sp0 * "." * sp0 * lpeg.Ct(parm2memberpat + tok.identifier_all)
local singlememberpat = sp0 * "." * sp0 * tok.identifier_all

local getstructcmd =  -- get<structname>[<idx>].<member> (<parm2>)? <<var>>
    arraypat * bothmemberpat * sp1 * tok.wvar

local setstructcmd =  -- set<structname>[<idx>].<<member>> (<parm2>)? <var>
    arraypat * bothmemberpat * sp1 * tok.rvar

local getperxvarcmd =  -- get<actor/player>var[<idx>].<varname> <<var>>
    arraypat * singlememberpat * sp1 * tok.wvar

local setperxvarcmd = -- set<actor/player>var[<idx>].<<varname>> <var>
    arraypat * singlememberpat * sp1 * tok.rvar

local function thisactor_to_pli(var)
    return (var=="_aci") and "_pli" or var
end

-- Function generating code for a struct read/write access.
local function StructAccess(Structname, writep, index, membertab)
    assert(type(membertab)=="table")
    -- Lowercase the member name for CON compatibility
    local member, parm2 = membertab[1]:lower(), membertab[2]

    local MemberCode = conl.StructAccessCode[Structname] or conl.StructAccessCode2[Structname]
    -- Look up array+member name first, e.g. "spriteext[%s].angoff".
    local armembcode = MemberCode[member]
    if (armembcode == nil) then
        errprintf("%s: invalid %s member `.%s'", g_lastkw, Structname, member)
        return "_MEMBINVALID"
    end

    if (type(armembcode)=="table") then
        -- Read and write accesses differ.
        armembcode = armembcode[writep and 2 or 1]
        if (armembcode==nil) then
            errprintf("%s access to %s[].%s is not available",
                      writep and "write" or "read", Structname, member)
            return "_MEMBNOACCESS"
        end
    end

    if (Structname~="userdef") then
        -- Count number of parameters ("%s"), don't count "%%s".
        local _, numparms = armembcode:gsub("[^%%]%%s", "", 2)
        if (#membertab ~= numparms) then
            local nums = { "one", "two" }
            errprintf("%s[].%s has %s parameter%s, but %s given", Structname,
                      member, nums[numparms], numparms==1 and "" or "s",
                      nums[#membertab])
            return "_MEMBINVPARM"
        end
    end

    -- THISACTOR special meanings
    if (Structname=="player" or Structname=="input") then
        index = thisactor_to_pli(index)
    elseif (Structname=="sector") then
        if (index=="_aci") then
            index = SPS".sectnum"
        end
    end

    -- METHOD_MEMBER
    local ismethod = (armembcode:find("%%s",1,true)~=nil)
    -- If ismethod is true, then the formatted string will now have an "%s"

    if (Structname=="userdef") then
--        assert(index==nil)
        assert(parm2==nil)
        return format(armembcode, parm2), ismethod
    else
        return format(armembcode, index, parm2), ismethod
    end
end

function lookup.array_expr(writep, structname, index, membertab)
    if (conl.StructAccessCode[structname] == nil) then
        -- Try a gamearray
        local ganame = g_gamearray[structname] and lookup.gamearray(structname)
        if (ganame == nil) then
            if (structname=="actorvar") then
                -- actorvar[] inline array expr
                -- XXX: kind of CODEDUP with GetOrSetPerxvarCmd() factory
                local gv = g_gamevar[structname]
                if (gv and bit.band(gv.flags, GVFLAG.PERX_MASK)~=GVFLAG.PERACTOR) then
                    errprintf("variable `%s' is not per-actor", structname, "actor")
                end

                if (membertab == nil) then
                    errprintf("actorvar[] requires a pseudo member (gamevar) name")
                    return "_INVALIDAV"
                end

                if (#membertab > 1) then
                    errprintf("actorvar[] cannot be used with a second parameter")
                    return "_INVALIDAV"
                end

                assert(#membertab == 1)
                return lookup.gamevar(membertab[1], index, writep)
            end

            errprintf("symbol `%s' is neither a struct nor a gamearray", structname)
            return "_INVALIDAR"
        end

        if (membertab ~= nil) then
            errprintf("gamearrays cannot be indexed with member names")
            return "_INVALIDAR"
        end

        assert(type(ganame)=="string")
        return format("%s[%s]", ganame, index)
    end

    local membercode, ismethod = StructAccess(structname, writep, index, membertab)
    -- Written METHOD_MEMBER syntax not supported as "qwe:method(asd) = val"
    -- isn't valid Lua syntax.
    assert(not (writep and ismethod))
    return membercode
end

local Access =
{
    sector = function(...) return StructAccess("sector", ...) end,
    wall = function(...) return StructAccess("wall", ...) end,
    xsprite = function(...) return StructAccess("sprite", ...) end,
    player = function(...) return StructAccess("player", ...) end,

    tspr = function(...) return StructAccess("tspr", ...) end,
    projectile = function(...) return StructAccess("projectile", ...) end,
    thisprojectile = function(...) return StructAccess("thisprojectile", ...) end,
    userdef = function(...) return StructAccess("userdef", ...) end,
    input = function(...) return StructAccess("input", ...) end,
}

local function GetStructCmd(accessfunc, pattern)
    return (pattern or getstructcmd) /
      function(idx, memb, var)
        return format("%s=%s", var, accessfunc(false, idx, memb))
      end
end

local function SetStructCmd(accessfunc, pattern)
    local function capfunc(idx, memb, var)
        local membercode, ismethod = accessfunc(true, idx, memb)
        if (ismethod) then
            -- METHOD_MEMBER syntax

            -- BE EXTRA CAREFUL! We must be sure that percent characters have
            -- not been smuggled into the member code string via variable names
            -- etc.
            local _, numpercents = membercode:gsub("%%", "", 2)
            assert(numpercents==1)

            return format(membercode, var)
        else
            return format("%s=%s", membercode, var)
        end
    end

    return (pattern or setstructcmd) / capfunc
end

-- <Setp>: whether the perxvar is set
local function GetOrSetPerxvarCmd(Setp, Actorp)
    local EXPECTED_PERX_BIT = Actorp and GVFLAG.PERACTOR or GVFLAG.PERPLAYER
    local pattern = (Setp and setperxvarcmd or getperxvarcmd)

    local function capfunc(idx, perxvarname, var)
        local gv = g_gamevar[perxvarname]
        if (gv and bit.band(gv.flags, GVFLAG.PERX_MASK)~=EXPECTED_PERX_BIT) then
            errprintf("variable `%s' is not per-%s", perxvarname, Actorp and "actor" or "player")
        end

        if (not Actorp) then
            -- THISACTOR -> player index for {g,s}etplayervar
            idx = thisactor_to_pli(idx)
        end

        if (Setp) then
            return format("%s=%s", lookup.gamevar(perxvarname, idx, true), var)
        else
            return format("%s=%s", var, lookup.gamevar(perxvarname, idx, false))
        end
    end

    return pattern / capfunc
end


local function n_s_fmt(n)
    return string.rep("%s,", n-1).."%s"
end

-- Various inner command handling functions / string capture strings.
local handle =
{
    NYI = function()
        errprintf("command `%s' not yet implemented", g_lastkw)
        return ""
    end,

    dynNYI = function()
        -- XXX: what if file name contains a double quote? (Similarly commands below.)
        return format([[print("%s:%d: `%s' not yet implemented")]],
                      g_filename, getlinecol(g_lastkwpos), g_lastkw)
    end,

    addlog = function()
        return format("print('%s:%d: addlog')", g_filename, getlinecol(g_lastkwpos))
    end,

    addlogvar = function(val)
        return format("printf('%s:%d: addlogvar %%s', %s)", g_filename, getlinecol(g_lastkwpos), val)
    end,

    debug = function(val)
        return format("print('%s:%d: debug %d')", g_filename, getlinecol(g_lastkwpos), val)
    end,

    getzrange = function(...)
        local v = {...}
        assert(#v == 10)  -- 4R 4W 2R
        return format("%s,%s,%s,%s=_con._getzrange(%s,%s,%s,%s,%s,%s)",
                      v[5], v[6], v[7], v[8],  -- outargs
                      v[1], v[2], v[3], v[4], v[9], v[10])  -- inargs
    end,

    hitscan = function(...)
        local v = {...}
        assert(#v == 14)  -- 7R 6W 1R
        local vals = {
            v[8], v[9], v[10], v[11], v[12], v[13],  -- outargs
            v[1], v[2], v[3], v[4], v[5], v[6], v[7], v[14]  -- inargs
        }
        return format("%s,%s,%s,%s,%s,%s=_con._hitscan(%s,%s,%s,%s,%s,%s,%s,%s)",
                     unpack(vals))
    end,

    neartag = function(...)
        local v = {...}
        assert(#v == 11)  -- 5R 4W 2R
        local vals = {
            v[6], v[7], v[8], v[9],  -- outargs
            v[1], v[2], v[3], v[4], v[5], v[10], v[11]  -- inargs
        }
        return format("%s,%s,%s,%s=_con._neartag(%s,%s,%s,%s,%s,%s,%s)",
                      unpack(vals))
    end,

    palfrom = function(...)
        local v = {...}
        return format(PLS":_palfrom(%d,%d,%d,%d)",
                      v[1] or 0, v[2] or 0, v[3] or 0, v[4] or 0)
    end,

    qsprintf = function(qdst, qsrc, ...)
        local codes = {...}
        return format("_con._qsprintf(%d,%d%s%s)", qdst, qsrc,
                      #codes>0 and "," or "", table.concat(codes, ','))
    end,

    move = function(mv, ...)
        local flags = {...}
        return format(ACS":set_move(%s,%d)", mv, (flags[1] and bit.bor(...)) or 0)
    end,

    rotatesprite = function(...)
        return format("_con.rotatesprite(%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)", ...)
    end,

    rotatesprite16 = function(...)
        return format("_con.rotatesprite(%s,%s/65536,%s/65536,%s,%s,%s,%s,%s,%s,%s,%s,%s)", ...)
    end,

    state = function(statename)
        if (g_funcname[statename]==nil) then
            errprintf("state `%s' not found.", statename)
            return "_NULLSTATE()"
        end
        return format("%s(_aci,_pli,_dist)", g_funcname[statename])
    end,

    addweapon = format("if (%s) then _con.longjmp() end", PLS":addweapon(%1,%2)"),

    -- Sound commands
    sound = "_con._sound(_aci,%1)",
    globalsound = "_con._globalsound(_pli,%1)",
    stopsound = "_con._stopsound(_aci,%1)",
    soundonce = "_con._soundonce(_aci,%1)",
}

local userdef_common_pat = (arraypat + sp1)/{} * lpeg.Cc(0) * lpeg.Ct(singlememberpat) * sp1

-- NOTE about prefixes: most is handled by all_alt_pattern(), however commands
-- that have no arguments and that are prefixes of other commands MUST be
-- suffixed with a "* #sp1" pattern.

local Cinner = {
    -- these can appear anywhere in the script
    ["break"] = cmd()
        / "do return end",
    ["return"] = cmd()  -- NLCF
        / "_con.longjmp()",

    state = cmd(I)
        / handle.state,

    --- 1. get*, set*
    getsector = GetStructCmd(Access.sector),
    getwall = GetStructCmd(Access.wall),
    getactor = GetStructCmd(Access.xsprite),
    getplayer = GetStructCmd(Access.player),

    getinput = GetStructCmd(Access.input),
    getprojectile = GetStructCmd(Access.projectile),
    getthisprojectile = GetStructCmd(Access.thisprojectile),
    gettspr = GetStructCmd(Access.tspr),
    -- NOTE: {get,set}userdef is the only struct that can be accessed without
    -- an "array part", e.g.  H266MOD has "setuserdef .weaponswitch 0" (space
    -- between keyword and "." is mandatory).
    -- NOTE2: userdef has at least three members with a second parameter:
    -- user_name, ridecule, savegame. Then there's wchoice. Given that they're
    -- arrays, I highly doubt that they worked (much less were safe) in CON.
    -- We disallow them, recent EDuke32 versions didn't expose them either.
    getuserdef = GetStructCmd(Access.userdef, userdef_common_pat * tok.wvar),

    getplayervar = GetOrSetPerxvarCmd(false, false),  -- THISACTOR
    getactorvar = GetOrSetPerxvarCmd(false, true),

    setsector = SetStructCmd(Access.sector),
    setwall = SetStructCmd(Access.wall),
    setactor = SetStructCmd(Access.xsprite),
    setplayer = SetStructCmd(Access.player),

    setinput = SetStructCmd(Access.input),
    setprojectile = SetStructCmd(Access.projectile),
    setthisprojectile = SetStructCmd(Access.thisprojectile),
    settspr = SetStructCmd(Access.tspr),
    setuserdef = SetStructCmd(Access.userdef, userdef_common_pat * tok.rvar),

    setplayervar = GetOrSetPerxvarCmd(true, false),  -- THISACTOR
    setactorvar = GetOrSetPerxvarCmd(true, true),

    setvarvar = varvarop / "%1=%2",
    addvarvar = varvaropf "+",
    -- NOTE the space after the minus sign so that e.g. "subvar x -1" won't get
    -- translated to "x=x--1" (-- being the Lua line comment start).
    subvarvar = varvaropf "- ",
    mulvarvar = varvaropf "*",
    divvarvar = varvaropf "_con._div",
    modvarvar = varvaropf "_con._mod",
    andvarvar = varvaropf "_bit.band",
    orvarvar = varvaropf "_bit.bor",
    xorvarvar = varvaropf "_bit.bxor",
    randvarvar = varvarop / "%1=_con._rand(%2)",

    setvar = varop / "%1=%2",
    addvar = varopf "+",
    subvar = varopf "- ",
    mulvar = varopf "*",
    divvar = varopf "_con._div",
    modvar = varopf "_con._mod",
    andvar = varopf "_bit.band",
    orvar = varopf "_bit.bor",
    xorvar = varopf "_bit.bxor",
    randvar = varop / "%1=_con._rand(%2)",
    shiftvarl = varopf "_bit.lshift",
    shiftvarr = varopf "_bit.rshift",

    --- 2. Math operations
    sqrt = cmd(R,W)
        / "%2=_gv.ksqrt(%1)",
    calchypotenuse = cmd(W,R,R)
        / "%1=_con._hypot(%2,%3)",
    sin = cmd(W,R)
        / "%1=_xmath.ksin(%2)",
    cos = cmd(W,R)
        / "%1=_xmath.kcos(%2)",
    mulscale = cmd(W,R,R,R)
        / "%1=_gv.Mulscale(%1,%2,%3)",
    getangle = cmd(W,R,R)
        / "%1=_gv.getangle(%2,%3)",
    getincangle = cmd(W,R,R)
        / "%1=_con._angdiff(%2,%3)",

    --- 3. Actors
    action = cmd(AC)
        / ACS":set_action(%1)",
    ai = cmd(AI)
        / ACS":set_ai(%1)",
    move = sp1 * tok.move * (sp1 * tok.define)^0
        / handle.move,

    cactor = cmd(D)
        / SPS":set_picnum(%1)",
    count = cmd(D)
        / ACS":set_count(%1)",
    cstator = cmd(D)
        / (SPS".cstat=_bit.bor(%1,"..SPS".cstat)"),
    cstat = cmd(D)
        / SPS".cstat=%1",
    clipdist = cmd(D)
        / SPS".clipdist=%1",
    sizeto = cmd(D,D)
        / "_con._sizeto(_aci,%1,%2)",  -- TODO: see control.lua:_sizeto
    sizeat = cmd(D,D)
        / (SPS".xrepeat,"..SPS".yrepeat=%1,%2"),
    strength = cmd(D)
        / SPS".extra=%1",
    addstrength = cmd(D)
        / (SPS".extra="..SPS".extra+%1"),
    spritepal = cmd(D)
        / SPS".pal=%1",

    hitradius = cmd(D,D,D,D,D)
        / "_con._A_RadiusDamage(_aci,%1,%2,%3,%4,%5)",
    hitradiusvar = cmd(R,R,R,R,R)
        / "_con._A_RadiusDamage(_aci,%1,%2,%3,%4,%5)",

    -- some commands taking read vars
    operaterespawns = cmd(R)
        / "_con._G_OperateRespawns(%1)",
    operatemasterswitches = cmd(R)
        / "_con._G_OperateMasterSwitches(%1)",
    checkactivatormotion = cmd(R)
        / CSV".RETURN=_con._checkactivatormotion(%1)",
    time = cmd(R)  -- no-op
        / "",
    inittimer = cmd(R)
        / "_con._inittimer(%1)",
    lockplayer = cmd(R)
        / PLS".transporter_hold=%1",
    quake = cmd(R)
        / "_gv.doQuake(%1,81)",  -- EARTHQUAKE
    jump = cmd(R)
        / handle.NYI,  -- will never be
    cmenu = cmd(R)
        / handle.NYI,
    checkavailweapon = cmd(R)  -- THISACTOR
        / function(pli)
              return format("_con._checkavailweapon(%s)", thisactor_to_pli(pli))
          end,
    checkavailinven = cmd(R)  -- THISACTOR
        / function(pli)
              return format("_con._selectnextinv(player[%s])", thisactor_to_pli(pli))
          end,
    guniqhudid = cmd(R)
        / "_gv._set_guniqhudid(%1)",
    echo = cmd(R)
        / "_con._echo(%1)",
    activatecheat = cmd(R)
        / handle.NYI,
    setgamepalette = cmd(R)
        / "_con._setgamepalette(_pli,%1)",

    -- Sound commands
    sound = cmd(D)
        / handle.sound,
    soundvar = cmd(R)
        / handle.sound,
    globalsound = cmd(D)
        / handle.globalsound,
    globalsoundvar = cmd(R)
        / handle.globalsound,
    stopsound = cmd(D)
        / handle.stopsound,
    stopsoundvar = cmd(R)
        / handle.stopsound,
    soundonce = cmd(D)
        / handle.soundonce,
    soundoncevar = cmd(R)
        / handle.soundonce,
    stopactorsound = cmd(R,R)
        / "_stopactorsound(%1,%2)",
    stopallsounds = cmd()
        / "_stopallsounds()",
    mikesnd = cmd()
        / format("_con._soundonce(_aci,%s)", SPS".yvel"),
    setactorsoundpitch = cmd(R,R,R)
        / "_con._setactorsoundpitch(%1,%2,%3)",

    -- some commands taking defines
    addammo = cmd(D,D)  -- NLCF
        / format("if (%s) then _con.longjmp() end", PLS":addammo(%1,%2)"),
    addweapon = cmd(D,D)  -- NLCF
        / handle.addweapon,
    debris = cmd(D,D)
        / "_con._debris(_aci, %1, %2)",
    addinventory = cmd(D,D)
        / format("_con._addinventory(%s,%%1,%%2,_aci)", PLS""),
    guts = cmd(D,D)
        / "_con._A_DoGuts(_aci,%1,%2)",

    spawn = cmd(D)
        / "_con.spawn(_aci,%1)",
    espawn = cmd(D)
        / CSV".RETURN=_con.spawn(_aci,%1)",
    espawnvar = cmd(R)
        / CSV".RETURN=_con.spawn(_aci,%1)",
    qspawn = cmd(D)
        / "_con.spawn(_aci,%1,true)",
    qspawnvar = cmd(R)
        / "_con.spawn(_aci,%1,true)",
    eqspawn = cmd(D)
        / CSV".RETURN=_con.spawn(_aci,%1,true)",
    eqspawnvar = cmd(R)
        / CSV".RETURN=_con.spawn(_aci,%1,true)",

    angoff = cmd(D)
        / "spriteext[_aci].angoff=%1",
    angoffvar = cmd(R)
        / "spriteext[_aci].angoff=%1",

    -- cont'd
    addkills = cmd(D)
        / (PLS".actors_killed="..PLS".actors_killed+%1;"..ACS".actorstayput=-1"),
    addphealth = cmd(D)
        / format("_con._addphealth(%s,_aci,%%1)", PLS""),
    debug = cmd(D)
        / handle.debug,
    endofgame = cmd(D)
        / "_con._endofgame(_pli,%1)",
    lotsofglass = cmd(D)
        / "_con._A_SpawnGlass(_aci,%1)",
    mail = cmd(D)
        / "_con._spawnmany(_aci,4410,%1)",  -- TODO: dyntile
    money = cmd(D)
        / "_con._spawnmany(_aci,1233,%1)",  -- TODO: dyntile
    paper = cmd(D)
        / "_con._spawnmany(_aci,4460,%1)",  -- TODO: dyntile
    sleeptime = cmd(D)
        / ACS".timetosleep=%1",

    eshoot = cmd(D)
        / CSV".RETURN=_con._shoot(_aci,%1)",
    eshootvar = cmd(R)
        / CSV".RETURN=_con._shoot(_aci,%1)",
    ezshoot = cmd(R,D)
        / CSV".RETURN=_con._shoot(_aci,%2,%1)",
    ezshootvar = cmd(R,R)
        / CSV".RETURN=_con._shoot(_aci,%2,%1)",
    shoot = cmd(D)
        / "_con._shoot(_aci,%1)",
    shootvar = cmd(R)
        / "_con._shoot(_aci,%1)",
    zshoot = cmd(R,D)
        / "_con._shoot(_aci,%2,%1)",
    zshootvar = cmd(R,R)
        / "_con._shoot(_aci,%2,%1)",

    fall = cmd()
        / "_con._VM_FallSprite(_aci)",
    flash = cmd()
        / format("_con._flash(%s,%s)", SPS"", PLS""),
    getlastpal = cmd()
        / "_con._getlastpal(_aci)",
    insertspriteq = cmd()
        / "_con._addtodelqueue(_aci)",
    killit = cmd()  -- NLCF
        / "_con.killit()",
    nullop = cmd()
        / "",  -- NOTE: really generate no code
    pkick = cmd()
        / format("_con._pkick(%s,%s)", PLS"", ACS""),
    pstomp = cmd()
        / PLS":stomp(_aci)",
    resetactioncount = cmd()
        / ACS":reset_acount()",
    resetcount = cmd()
        / ACS":set_count(0)",
    resetplayer = cmd()  -- NLCF
        / "if (_con._VM_ResetPlayer2(_pli,_aci)) then _con.longjmp() end",
    respawnhitag = cmd()
        / format("_con._respawnhitag(%s)", SPS""),
    tip = cmd()
        / PLS".tipincs=26",
    tossweapon = cmd()
        / "",  -- TODO_MP
    wackplayer = cmd()
        / PLS":wack()",

    -- player/sprite searching
    findplayer = cmd(W)
        / CSV".RETURN,%1=_con._findplayer(_pli,_aci)",  -- player index, distance
    findotherplayer = cmd(W)
        / CSV".RETURN,%1=0,0x7fffffff",  -- TODO_MP
    findnearspritezvar = cmd(D,R,R,W)
        / "%4=_con._findnear(_aci,true,'z',%1,%2,%3)",
    findnearspritez = cmd(D,D,D,W)
        / "%4=_con._findnear(_aci,true,'z',%1,%2,%3)",
    findnearsprite3dvar = cmd(D,R,W)
        / "%3=_con._findnear(_aci,true,'d3',%1,%2)",
    findnearsprite3d = cmd(D,D,W)
        / "%3=_con._findnear(_aci,true,'d3',%1,%2)",
    findnearspritevar = cmd(D,R,W)
        / "%3=_con._findnear(_aci,true,'d2',%1,%2)",
    findnearsprite = cmd(D,D,W)
        / "%3=_con._findnear(_aci,true,'d2',%1,%2)",
    findnearactorzvar = cmd(D,R,R,W)
        / "%4=_con._findnear(_aci,false,'z',%1,%2,%3)",
    findnearactorz = cmd(D,D,D,W)
        / "%4=_con._findnear(_aci,false,'z',%1,%2,%3)",
    findnearactor3dvar = cmd(D,R,W)
        / "%3=_con._findnear(_aci,false,'d3',%1,%2)",
    findnearactor3d = cmd(D,D,W)
        / "%3=_con._findnear(_aci,false,'d3',%1,%2)",
    findnearactorvar = cmd(D,R,W)
        / "%3=_con._findnear(_aci,false,'d2',%1,%2)",
    findnearactor = cmd(D,D,W)
        / "%3=_con._findnear(_aci,false,'d2',%1,%2)",

    -- quotes
    qsprintf = sp1 * tok.rvar * sp1 * tok.rvar * (sp1 * tok.rvar)^-32
        / handle.qsprintf,
    qgetsysstr = cmd(R,R)
        / "_con._qgetsysstr(%1,%2,_pli)",
    qstrcat = cmd(R,R)
        / "_con._qstrcat(%1,%2)",
    qstrcpy = cmd(R,R)
        / "_con._qstrcpy(%1,%2)",
    qstrlen = cmd(W,R)
        / "%1=_con._qstrlen(%2)",
    qstrncat = cmd(R,R)
        / handle.NYI,
    qsubstr = cmd(R,R)
        / handle.NYI,
    quote = cmd(D)
        / "_con._quote(_pli,%1)",
    userquote = cmd(R)
        / "_con._userquote(%1)",
    getkeyname = cmd(R,R,R)
        / "_con._getkeyname(%1,%2,%3)",
    getpname = cmd(R,R)  -- THISACTOR
        / handle.NYI,

    -- array stuff
    copy = sp1 * tok.gamearray * arraypat * sp1 * tok.gamearray * arraypat * sp1 * tok.rvar
        / "%1:copyto(%2,%3,%4,%5)",
    setarray = sp1 * tok.gamearray * arraypat * sp1 * tok.rvar
        / "%1[%2]=%3",
    resizearray = cmd(GARI,R)
        / "%1:resize(%2)",
    getarraysize = cmd(GARI,W)
        / "%2=%1._size",
    readarrayfromfile = cmd(GARI,D)
        / "%1:read(%2)",
    writearraytofile = cmd(GARI,D)
        / "%1:write(%2)",

    -- Persistence
    clearmapstate = cmd(R)
        / handle.dynNYI,
    loadmapstate = cmd()
        / handle.dynNYI,
    savemapstate = cmd()
        / handle.dynNYI,
    savegamevar = cmd(R)
        / handle.dynNYI,
    readgamevar = cmd(W)
        / handle.dynNYI,
    savenn = cmd(D)
        / handle.dynNYI,
    save = cmd(D)
        / handle.dynNYI,

    addlogvar = cmd(R)
        / handle.addlogvar,
    addlog = cmd() * #sp1
        / handle.addlog,
    addweaponvar = cmd(R,R)  -- NLCF
        / handle.addweapon,
    cansee = cmd(R,R,R,R,R,R,R,R,W)
        / "%9=cansee(_geom.ivec3(%1,%2,%3),%4, _geom.ivec3(%5,%6,%7),%8) and 1 or 0",
    canseespr = cmd(R,R,W)
        / "%3=_con._canseespr(%1,%2)",
    changespritesect = cmd(R,R)
        / "sprite.changesect(%1,%2)",
    changespritestat = cmd(R,R)
        / "sprite.changestat(%1,%2)",
    displayrand = cmd(W)
        / "%1=_con._displayrand(32767)",
    displayrandvar = cmd(W,D)
        / "%1=_con._displayrand(%2)",
    displayrandvarvar = cmd(W,R)
        / "%1=_con._displayrand(%2)",
    dist = cmd(W,R,R)
        / "%1=_xmath.dist(sprite[%1],sprite[%2])",
    ldist = cmd(W,R,R)
        / "%1=_xmath.ldist(sprite[%1],sprite[%2])",
    dragpoint = cmd(R,R,R)
        / handle.NYI,
    rotatepoint = cmd(R,R,R,R,R,W,W)
        / "%6,%7=_con._rotatepoint(%1,%2,%3,%4,%5)",

    -- collision detection etc.
    hitscan = cmd(R,R,R,R,R,R,R,W,W,W,W,W,W,R)  -- 7R 6W 1R
        / handle.hitscan,
    clipmove = cmd(W,W,W,R,W,R,R,R,R,R,R)
        / handle.NYI,
    clipmovenoslide = cmd(W,W,W,R,W,R,R,R,R,R,R)
        / handle.NYI,
    lineintersect = cmd(R,R,R,R,R,R,R,R,R,R,W,W,W,W)  -- 10R 4W
        / handle.NYI,
    rayintersect = cmd(R,R,R,R,R,R,R,R,R,R,W,W,W,W)  -- 10R 4W
        / handle.NYI,
    movesprite = cmd(R,R,R,R,R,W)
        / "%6=_con._movesprite(%1,%2,%3,%4,%5)",
    neartag = cmd(R,R,R,R,R,W,W,W,W,R,R)  -- 5R 4W 2R
        / handle.neartag,
    getzrange = cmd(R,R,R,R,W,W,W,W,R,R)
        / handle.getzrange,

    -- screen text and numbers display
    gametext = cmd(R,R,R,R,R,R,R,R,R,R,R)  -- 11 R
        / function(...)
              return format("_con._gametext("..n_s_fmt(11)..",65536)", ...)
          end,
    gametextz = cmd(R,R,R,R,R,R,R,R,R,R,R,R)  -- 12 R
        / function(...)
              return format("_con._gametext("..n_s_fmt(12)..")", ...)
          end,
    digitalnumber = cmd(R,R,R,R,R,R,R,R,R,R,R)  -- 11R
        / function(...)
              return format("_con._digitalnumber("..n_s_fmt(11)..",65536)", ...)
          end,
    digitalnumberz = cmd(R,R,R,R,R,R,R,R,R,R,R,R)  -- 12R
        / function(...)
              return format("_con._digitalnumber("..n_s_fmt(12)..")", ...)
          end,
    minitext = cmd(R,R,R,R,R)
        / "_con._minitext(%1,%2,%3,%4,%5)",

    palfrom = (sp1 * tok.define)^-4
        / handle.palfrom,

    activatebysector = cmd(R,R)
        / "_con._activatebysector(%1,%2)",
    operateactivators = cmd(R,R)  -- THISACTOR
        / function(tag, pli)
              return format("_con._operateactivators(%s,%s)", tag, thisactor_to_pli(pli))
          end,
    operatesectors = cmd(R,R)
        / "_con._operatesectors(%1,%2)",
    operate = cmd() * #sp1
        / "_con._operate(_aci)",

    myos = cmd(R,R,R,R,R)
        / "_con._myos(%1,%2,65536,%3,%4,%5)",
    myosx = cmd(R,R,R,R,R)
        / "_con._myos(%1,%2,32768,%3,%4,%5)",
    myospal = cmd(R,R,R,R,R,R)
        / "_con._myos(%1,%2,65536,%3,%4,%5,%6)",
    myospalx = cmd(R,R,R,R,R,R)
        / "_con._myos(%1,%2,32768,%3,%4,%5,%6)",

    headspritesect = cmd(W,R)
        / "%1=sprite._headspritesect[%2]",
    headspritestat = cmd(W,R)
        / "%1=sprite._headspritestat[%2]",
    nextspritesect = cmd(W,R)
        / "%1=sprite._nextspritesect[%2]",
    nextspritestat = cmd(W,R)
        / "%1=sprite._nextspritestat[%2]",
    prevspritesect = cmd(W,R)
        / "%1=sprite._prevspritesect[%2]",
    prevspritestat = cmd(W,R)
        / "%1=sprite._prevspritestat[%2]",

    redefinequote = sp1 * tok.define * newline_term_string
        / function(qnum, qstr) return format("_con._definequote(%d,%q)", qnum, stripws(qstr)) end,
    rotatesprite = cmd(R,R,R,R,R,R,R,R,R,R,R,R)  -- 12R
        / handle.rotatesprite,
    rotatesprite16 = cmd(R,R,R,R,R,R,R,R,R,R,R,R)  -- 12R
        / handle.rotatesprite16,
    sectorofwall = cmd(W,R,R)
        / handle.NYI,
    sectclearinterpolation = cmd(R)
        / "_con._togglesectinterp(%1,0)",
    sectsetinterpolation = cmd(R)
        / "_con._togglesectinterp(%1,1)",

    sectgethitag = cmd()
        / (CSV".HITAG=sector["..SPS".sectnum].hitag"),
    sectgetlotag = cmd()
        / (CSV".LOTAG=sector["..SPS".sectnum].lotag"),
    spgethitag = cmd()
        / (CSV".HITAG="..SPS".hitag"),
    spgetlotag = cmd()
        / (CSV".LOTAG="..SPS".lotag"),
    gettextureceiling = cmd()
        / (CSV".TEXTURE=sector["..SPS".sectnum].ceilingpicnum"),
    gettexturefloor = cmd()
        / (CSV".TEXTURE=sector["..SPS".sectnum].floorpicnum"),

    startlevel = cmd(R,R)
        / "_con._startlevel(%1,%2)",
    starttrack = cmd(D)
        / "_con._starttrack(%1)",
    starttrackvar = cmd(R)
        / "_con._starttrack(%1)",

    setaspect = cmd(R,R)
        / "_con._setaspect(%1,%2)",
    showview = cmd(R,R,R,R,R,R,R,R,R,R)  -- 10R
        / "",  -- TODO
    showviewunbiased = cmd(R,R,R,R,R,R,R,R,R,R)  -- 10R
        / "",  -- TODO
    smaxammo = cmd(R,R)
        / PLS":set_max_ammo_amount(%1,%2)",
    gmaxammo = cmd(R,W)
        / ("%2="..PLS".max_ammo_amount[%1]"),
    spriteflags = cmd(R)  -- also see outer
        / ACS".flags=%1",
    ssp = cmd(R,R)
        / handle.NYI,
    setsprite = cmd(R,R,R,R)
        / "sprite[%1]:setpos(_geom.ivec3(%1,%2,%3))",
    updatesector = cmd(R,R,W)
        / format("%%3=updatesector(_geom.ivec3(%%1,%%2),%s)", SPS".sectnum"),
    updatesectorz = cmd(R,R,R,W)
        / format("%%4=updatesectorz(_geom.ivec3(%%1,%%2,%%3),%s)", SPS".sectnum"),

    getactorangle = cmd(W)
        / ("%1="..SPS".ang"),
    setactorangle = cmd(R)
        / SPS".ang=_bit.band(%1,2047)",
    getplayerangle = cmd(W)
        / ("%1="..PLS".ang"),
    setplayerangle = cmd(R)
        / PLS".ang=_bit.band(%1,2047)",
    getangletotarget = cmd(W)
        / "%1=_con._angtotarget(_aci)",

    getceilzofslope = cmd(R,R,R,W)
        / "%4=sector[%1]:ceilingzat(_geom.ivec3(%2,%3))",
    getflorzofslope = cmd(R,R,R,W)
        / "%4=sector[%1]:floorzat(_geom.ivec3(%2,%3))",
    getcurraddress = cmd(W)
        / handle.NYI,  -- will never be
    getticks = cmd(W)
        / "%1=_gv.getticks()",
    gettimedate = cmd(W,W,W,W,W,W,W,W)
        / "%1,%2,%3,%4,%5,%6,%7,%8=_con._gettimedate()",
}

local Cif = {
    ifai = cmd(AI)
        / ACS":has_ai(%1)",
    ifaction = cmd(AC)
        / ACS":has_action(%1)",
    ifmove = cmd(MV)
        / ACS":has_move(%1)",

    ifrnd = cmd(D)
        / "_con.rnd(%1)",
    ifpdistl = cmd(D)
        / function(val) return "_dist<"..val, "", "_con._sleepcheck(_aci,_dist)" end,
    ifpdistg = cmd(D)
        / function(val) return "_dist>"..val, "", "_con._sleepcheck(_aci,_dist)" end,
    ifactioncount = cmd(D)
        / ACS":get_acount()>=%1",
    ifcount = cmd(D)
        / ACS":get_count()>=%1",
    ifactor = cmd(D)
        / SPS".picnum==%1",
    ifstrength = cmd(D)
        / SPS".extra<=%1",
    ifspawnedby = cmd(D)
        / ACS".picnum==%1",
    ifwasweapon = cmd(D)
        / ACS".picnum==%1",
    ifgapzl = cmd(D)  -- factor into a con.* function?
        / format("_bit.arshift(%s-%s,8)<%%1", ACS".floorz", ACS".ceilingz"),
    iffloordistl = cmd(D)
        / format("(%s-%s)<=256*%%1", ACS".floorz", SPS".z"),
    ifceilingdistl = cmd(D)
        / format("(%s-%s)<=256*%%1", SPS".z", ACS".ceilingz"),
    ifphealthl = cmd(D)
        / format("sprite[%s].extra<%%1", PLS".i"),
    ifspritepal = cmd(D)
        / SPS".pal==%1",
    ifgotweaponce = cmd(D)
        / "false",  -- TODO_MP
    ifangdiffl = cmd(D)
        / format("_con._angdiffabs(%s,%s)<=%%1", PLS".ang", SPS".ang"),
    ifsound = cmd(D)
        / "_con._soundplaying(_aci,%1)",
    -- vvv TODO: this is not correct for GET_ACCESS or GET_SHIELD.
    ifpinventory = cmd(D,D)
        / format("_con._checkpinventory(%s,%%1,%%2,_aci)", PLS""),

    ifvarl = cmd(R,D)
        / "%1<%2",
    ifvarg = cmd(R,D)
        / "%1>%2",
    ifvare = cmd(R,D)
        / "%1==%2",
    ifvarn = cmd(R,D)
        / "%1~=%2",
    ifvarand = cmd(R,D)
        / "_bit.band(%1,%2)~=0",
    ifvaror = cmd(R,D)
        / "_bit.bor(%1,%2)~=0",
    ifvarxor = cmd(R,D)
        / "_bit.bxor(%1,%2)~=0",
    ifvareither = cmd(R,D)
        / "%1~=0 or %2~=0",

    ifvarvarl = cmd(R,R)
        / "%1<%2",
    ifvarvarg = cmd(R,R)
        / "%1>%2",
    ifvarvare = cmd(R,R)
        / "%1==%2",
    ifvarvarn = cmd(R,R)
        / "%1~=%2",
    ifvarvarand = cmd(R,R)
        / "_bit.band(%1,%2)~=0",
    ifvarvaror = cmd(R,R)
        / "_bit.bor(%1,%2)~=0",
    ifvarvarxor = cmd(R,R)
        / "_bit.bxor(%1,%2)~=0",
    ifvarvareither = cmd(R,R)
        / "%1~=0 or %2~=0",

    ifactorsound = cmd(R,R)
        / "_con._soundplaying(%1,%2)",

    ifp = (sp1 * tok.define)^1
        / function (...) return format("_con._ifp(%d,_pli,_aci)", bit.bor(...)) end,
    ifsquished = cmd()
        / "false",  -- TODO
    ifserver = cmd()
        / "false",  -- TODO_MP
    ifrespawn = cmd()
        / format("_con._checkrespawn(%s)", SPS""),
    ifoutside = cmd()
        / format("_bit.band(sector[%s].ceilingstat,1)~=0", SPS".sectnum"),
    ifonwater = cmd()
        / format("sector[%s].lotag==1 and _math.abs(%s-sector[%s].floorz)<32*256",
                 SPS".sectnum", SPS".z", SPS".sectnum"),
    ifnotmoving = cmd()
        / "_bit.band(actor[_aci].movflag,49152)>16384",
    ifnosounds = cmd()
        / "not _con._ianysound()",
    ifmultiplayer = cmd()
        / "false",  -- TODO_MP
    ifinwater = cmd()
        / format("sector[%s].lotag==2", SPS".sectnum"),
    ifinspace = cmd()
        / format("_con._checkspace(%s,false)", SPS".sectnum"),
    ifinouterspace = cmd()
        / format("_con._checkspace(%s,true)", SPS".sectnum"),
    ifhitweapon = cmd()
        / "_con._A_IncurDamage(_aci)>=0",
    ifhitspace = cmd()
        / "_con._testkey(_pli,29)",  -- XXX
    ifdead = cmd()
        / SPS".extra<=0",
    ifclient = cmd()
        / "false",  -- TODO_MP
    ifcanshoottarget = cmd()
        / "_con._canshoottarget(_dist,_aci)",
    ifcanseetarget = cmd()  -- XXX: 1536 is SLEEPTIME
        / function() return format("_con._canseetarget(%s,%s)", SPS"", PLS""), ACS".timetosleep=1536" end,
    ifcansee = cmd() * #sp1
        / format("_con._cansee(_aci,%s)", PLS""),
    ifbulletnear = cmd()
        / "_con._bulletnear(_aci)",
    ifawayfromwall = cmd()
        / format("_con._awayfromwall(%s,108)", SPS""),
    ifactornotstayput = cmd()
        / ACS".actorstayput==-1",
}


----==== Tracing and reporting ====----

-- g_newlineidxs will contain the 1-based file offsets to "\n" characters
local g_newlineidxs = {}

-- Returns index into the sorted table tab such that
--   tab[index] <= searchelt < tab[index+1].
-- Preconditions:
--  tab[i] < tab[i+1] for 0 <= i < #tab
--  tab[0] <= searchelt < tab[#tab]
-- If #tab is less than 2, returns 0. This plays nicely with newline index
-- tables like { [0]=0, [1]=len+1 }, e.g. if the file doesn't contain any.
local function bsearch(tab, searchelt)
--    printf("bsearch(tab, %d)", searchelt)
    local l, r = 0, #tab
    local i

    if (r < 2) then
        return 0
    end

    while (l ~= r) do
        i = l + math.ceil((r-l)/2)  -- l < i <= r
        assert(l < i and i <= r)
        local elt = tab[i]
--        printf("l=%d tab[%d]=%d r=%d", l, i, elt, r)

        if (searchelt == elt) then
            return i
        end

        if (searchelt < elt) then
            r = i-1
        else  -- (searchelt > elt)
            l = i
        end
    end

--    printf("return tab[%d]=%d", l, tab[l])
    return l
end

function getlinecol(pos)  -- local
    assert(type(pos)=="number")
    local line = bsearch(g_newlineidxs, pos)
    assert(line and g_newlineidxs[line]<=pos and pos<g_newlineidxs[line+1])
    local col = pos-g_newlineidxs[line]
    return line+1, col-1
end

-- A generic trace function, prints a position together with the match content.
-- The 'doit' parameter can be used to temporarily enable/disable a particular
-- tracing function.
local function TraceFunc(pat, label, doit)
    assert(doit ~= nil)
    pat = Pat(pat)

    if (doit) then
        local function tfunc(subj, pos, a)
            printf("%s:%s: %s", linecolstr(pos), label, a)
            return true
        end
        pat = lpeg.Cmt(pat, tfunc)
    elseif (label=="kw") then  -- HACK
        local function tfunc(subj, pos, a)
            g_lastkwpos = pos
            g_lastkw = a
            return true
        end
        -- XXX: is there a better way?
        pat = lpeg.Cmt(pat, tfunc)
    end

    return pat
end

local function BadIdent(pat)
    local function tfunc(subj, pos, a)
        if (g_warn["bad-identifier"] and not g_badids[a]) then
            warnprintf("bad identifier: %s", a)
            g_badids[a] = true
        end
        return true
    end
    return lpeg.Cmt(Pat(pat), tfunc)
end

-- These are tracers for specific patterns which can be disabled
-- if desired.
local function Keyw(kwname) return TraceFunc(kwname, "kw", false) end
local function NotKeyw(text) return TraceFunc(text, "!kw", false) end
local function Ident(idname) return TraceFunc(idname, "id", false) end
local function Stmt(cmdpat) return TraceFunc(cmdpat, "st", false) end

--local function Temp(kwname) return TraceFunc(kwname, "temp", true) end
--Cinner["myosx"] = Temp(Cinner["myosx"])

----==== Translator continued ====----
local function after_inner_cmd_Cmt(subj, pos, ...)
    local capts = {...}

    if (g_numerrors == inf) then
        return nil
    end

    if (type(capts[1])=="string" and capts[2]==nil) then
        return true, capts[1] .."--"..linecolstr(pos) --TEMP
    end

    return true
end

local function after_if_cmd_Cmt(subj, pos, ...)
    local capts = {...}

    if (g_numerrors == inf) then
        return nil
    end

    if (capts[1] ~= nil) then
        assert(#capts <= 3)
        for i=1,#capts do
            assert(type(capts[i]=="string"))
        end
        return true, unpack(capts, 1, #capts)
    end

    return true
end

local function after_cmd_Cmt(subj, pos, ...)
    if (g_numerrors == inf) then
--        print("Aborting parsing...")
        return nil  -- make the match fail, bail out of parsing
    end

    return true  -- don't return any captures
end

-- attach the command names at the front!
local function attachnames(kwtab, matchtimefunc)
    for cmdname,cmdpat in pairs(kwtab) do
        -- The match-time function capture at the end is so that every command
        -- acts as a barrier to captures to delay (but not fully prevent) stack
        -- overflow (and to make lpeg.match return a subject position at the
        -- end)
        kwtab[cmdname] = lpeg.Cmt(Keyw(cmdname) * cmdpat, matchtimefunc)
    end
end

attachnames(Couter, after_cmd_Cmt)
attachnames(Cinner, after_inner_cmd_Cmt)
attachnames(Cif, after_if_cmd_Cmt)


-- Takes one or more tables and +'s all its patterns together in reverse
-- lexicographical order.
-- Each such PATTAB must be a table that maps command names to their patterns.
local function all_alt_pattern(...)
    local cmds = {}

    local args = {...}
    assert(#args <= 2)

    for argi=1,#args do
        local pattab = args[argi]

        -- pairs() iterates in undefined order, so we first fill in the names...
        for cmdname,_ in pairs(pattab) do
            cmds[#cmds+1] = cmdname
        end
    end

    -- ...and then sort them in ascending lexicographical order
    table.sort(cmds)

    local pat = Pat(false)

    for i=1,#cmds do
        local ourpat = args[1][cmds[i]] or args[2][cmds[i]]
        -- shorter commands go at the end!
        pat = pat + ourpat
    end

    return pat
end

-- actor ORGANTIC is greeting!
local function warn_on_lonely_else(pos)
    pwarnprintf(pos, "found `else' with no `if'")
end

local con_inner_command = all_alt_pattern(Cinner)
local con_if_begs = all_alt_pattern(Cif)

local lone_else = (POS() * "else" * sp1)/warn_on_lonely_else

local stmt_list = Var("stmt_list")
-- possibly empty statement list:
local stmt_list_or_eps = lpeg.Ct((stmt_list * sp1)^-1)
local stmt_list_nosp_or_eps = lpeg.Ct((stmt_list * (sp1 * stmt_list)^0)^-1)

-- Reused LPeg patterns
local common = {}

-- common to actor and useractor: <name/tilenum> [<strength> [<action> [<move> [<flags>... ]]]]
common.actor_end = sp1 * lpeg.Ct(tok.define *
    (sp1 * tok.define *
     (sp1 * tok.action *
      (sp1 * tok.move *
       (sp1 * tok.define)^0
      )^-1
     )^-1
    )^-1)
* sp1 * stmt_list_or_eps * "enda"

common.block_begin = lpeg.Cc(nil) / function()
    g_switchCode = {}
end

common.block_end = lpeg.Cc(nil) / function()
    if (#g_switchCode > 0) then
        addcode(g_switchCode)
    end
    g_switchCode = nil
end

--== block delimiters (no syntactic recursion) ==--
local Cblock = {
    -- actor (...)
    actor = lpeg.Cc(nil) * common.actor_end / on.actor_end,
    -- useractor <actortype> (...)
    useractor = sp1 * tok.define * common.actor_end / on.actor_end,
    -- eventloadactor <name/tilenum>
    eventloadactor = sp1 * tok.define * sp1 * stmt_list_or_eps * "enda"
        / on.eventloadactor_end,

    onevent = sp1 * tok.define * sp1 * stmt_list_or_eps * "endevent"
        / on.event_end,

    state = sp1 * (lpeg.Cmt(tok.identifier, on.state_begin_Cmt)) * sp1 * stmt_list_or_eps * tok.state_ends
        / on.state_end,
}

for cmdname, cmdpat in pairs(Cblock) do
    Cblock[cmdname] = common.block_begin * cmdpat * common.block_end
end

attachnames(Cblock, after_cmd_Cmt)


local t_good_identifier = Range("AZ", "az", "__") * Range("AZ", "az", "__", "09")^0

-- CON isaltok also has chars in "{}.", but these could potentially
-- interfere with *CON* syntax.  The "]" is so that the number in e.g. array[80]
-- isn't considered a broken identifier.
-- "-" is somewhat problematic, but we allow it only as 2nd and up character, so
-- there's no ambiguity with unary minus.  (Commands must be separated by spaces
-- in CON, so a trailing "-" is "OK", too.)
-- This is broken in itself, so we ought to make a compatibility/modern CON switch.
local t_broken_identifier = BadIdent(-((tok.number + t_good_identifier) * (sp1 + Set("[]:"))) *
                                     (alphanum + Set(BAD_ID_CHARS0)) * (alphanum + Set(BAD_ID_CHARS1))^0)

-- These two tables hold code to be inserted at a later point: either at
-- the end of the "if" body, or the end of the whole "if [else]" block.
-- For CON interpreter patterns like these:
--  VM_CONDITIONAL(<condition>);
--  <do_something_afterwards>
-- (Still not the same if the body returns or jumps out)
local g_endIfCode = {}
local g_endIfElseCode = {}

local function add_deferred_code(tab, lev, str)
    if (str ~= nil) then
        assert(type(str)=="string")
        tab[lev] = str
    end
end

local function get_deferred_code(tab, lev, code)
    if (tab[lev]) then
        code = code..tab[lev]
        tab[lev] = nil
    end
    return code
end

local function begin_if_fn(condstr, endifstr, endifelsestr)
    assert(type(condstr)=="string")

    add_deferred_code(g_endIfCode, g_iflevel, endifstr)
    add_deferred_code(g_endIfElseCode, g_ifelselevel, endifelsestr)

    g_iflevel = g_iflevel+1
    g_ifelselevel = g_ifelselevel+1

    return format("if (%s) then", condstr)
end

local function end_if_fn()
    g_iflevel = g_iflevel-1
    local code = get_deferred_code(g_endIfCode, g_iflevel, "")
    if (code ~= "") then
        return code
    end
end

local function end_if_else_fn()
    g_ifelselevel = g_ifelselevel-1
    return get_deferred_code(g_endIfElseCode, g_ifelselevel, "end ")
end

function on.switch_end(testvar, blocks)
    local SW = format("_SW[%d]", g_switchCount)
    local swcode = { format("%s={", SW) }
    local have = {}
    local havedefault = false

    for i=1,#blocks do
        local block = blocks[i]
        assert(#block >= 1)
        local isdefault = (#block==1)
        local index = isdefault and "'default'" or tostring(block[1])

        if (have[index]) then
            if (isdefault) then
                errprintf("duplicate 'default' block in switch statement")
                return "_INVALIDSW()"
            else
                warnprintf("duplicate case %s in switch statement", index)
            end
        end
        have[index] = true

        swcode[#swcode+1] = format("[%s]=function(_aci,_pli,_dist)", index)
        -- insert the case/default code:
        swcode[#swcode+1] = block[#block]
        swcode[#swcode+1] = "end,"
    end

    swcode[#swcode+1] = "}"

    -- insert additional case test numbers (e.g. case 0: >>> case 1 <<<: <code...>)
    for i=1,#blocks do
        local block = blocks[i]
        for j=2,#block-1 do
            local index = tostring(block[j])
            swcode[#swcode+1] = format("%s[%d]=%s[%d]", SW, index, SW, tostring(block[1]))
        end
    end

    assert(g_switchCode ~= nil)
    g_switchCode[#g_switchCode+1] = swcode

    -- The code for the switch statement itself:
    local code = format("_con._switch(_SW[%d], %s, _aci,_pli,_dist)", g_switchCount, testvar)
    g_switchCount = g_switchCount+1
    return code
end


--- The final grammar!
local Grammar = Pat{
    -- The starting symbol.
    -- A translation unit is a (possibly empty) sequence of outer CON
    -- commands, separated by at least one whitespace which may be
    -- omitted at the EOF.
    sp0 * (all_alt_pattern(Couter, Cblock) * sp1)^0,

    -- Some often-used terminals follow.  These appear here because we're
    -- hitting a limit with LPeg else.
    -- http://lua-users.org/lists/lua-l/2008-11/msg00462.html

    -- NOTE: NW demo (NWSNOW.CON) contains a Ctrl-Z char (decimal 26)
    whitespace = Set(" \t\r\26") + newline + Set("(),;") + comment + linecomment,

    t_number = POS() * lpeg.C(
        tok.maybe_minus * ((Pat("0x") + "0X") * Range("09", "af", "AF")^1 * Pat("h")^-1
                         + Range("09")^1)
                             ) / parse_number,

    t_identifier_all = lpeg.C(t_broken_identifier + t_good_identifier),
    -- NOTE: -conl.keyword alone would be wrong, e.g. "state breakobject":
    -- NOTE 2: The + "[" is so that stuff like
    --   getactor[THISACTOR].x x
    --   getactor[THISACTOR].y y
    -- is parsed correctly.  (Compared with this:)
    --   getactor[THISACTOR].x x
    --   getactor [THISACTOR].y y
    -- This is in need of cleanup!
    t_identifier = -NotKeyw(conl.keyword * (sp1 + "[")) * tok.identifier_all,
    -- TODO?: SST TC has e.g. "1267AT", relying on it to be parsed as a number "1267".
    -- However, this conflicts with bad-identifiers, so it should be checked last.
    -- This would also handle LNGA2's "00000000h", though would give problems with
    -- e.g. "800h" (hex 0x800 or decimal 800?).
    t_define = (POS() * lpeg.C(tok.maybe_minus) * tok.identifier / lookup.defined_label) + tok.number,

    -- Defines and constants can take the place of vars that are only read.
    -- XXX: now, when tok.rvar fails, the tok.define failure message is printed.
    t_rvar = Var("t_botharrayexp") + lpeg.Cmt(tok.identifier, maybe_gamevar_Cmt) + tok.define,
    -- For written-to vars, only (non-parm2) array exprs and writable gamevars
    -- are permitted.  NOTE: C-CON doesn't support inline array exprs here.
    t_wvar = Var("t_singlearrayexp") / function() errprintf("t_wvar: array exprs NYI") return "_NYIVAR" end
        + (tok.identifier / function(id) return lookup.gamevar(id, "_aci", true) end),

    t_gamearray = Var("t_identifier") / lookup.gamearray,

    t_move =
        POS()*tok.identifier / function(...) return lookup.composite(LABEL.MOVE, ...) end +
        POS()*tok.number / function(...) return check_composite_literal(LABEL.MOVE, ...) end,

    t_ai =
        POS()*tok.identifier / function(...) return lookup.composite(LABEL.AI, ...) end +
        POS()*tok.number / function(...) return check_composite_literal(LABEL.AI, ...) end,

    t_action =
        POS()*tok.identifier / function(...) return lookup.composite(LABEL.ACTION, ...) end +
        POS()*tok.number / function(...) return check_composite_literal(LABEL.ACTION, ...) end,

    -- New-style inline arrays and structures.
    t_botharrayexp = tok.identifier * arraypat * bothmemberpat^-1
        / function(...) return lookup.array_expr(false, ...) end,
    t_singlearrayexp = tok.identifier * arraypat * singlememberpat^-1,

    -- SWITCH
    switch_stmt = Keyw("switch") * sp1 * tok.rvar *
        lpeg.Ct((Var("case_block") + Var("default_block"))^0) * sp1 * "endswitch"
        / on.switch_end,

    -- NOTE: some old DNWMD has "case: PIGCOP".  I don't think I'll allow that.
    case_block = lpeg.Ct((sp1 * Keyw("case") * sp1 * tok.define * (sp0*":")^-1)^1 * sp1 *
                         stmt_list_nosp_or_eps), -- * "break",

    default_block = lpeg.Ct(sp1 * Keyw("default") * (sp0*":"*sp0 + sp1) *
                            stmt_list_nosp_or_eps),  -- * "break",

    optional_else = (sp1 * lpeg.C("else") * sp1 * Var("single_stmt"))^-1,

    if_else_bodies = Var("single_stmt2") * (Pat("")/end_if_fn) * Var("optional_else"),

    if_stmt = con_if_begs/begin_if_fn * sp1
        * Var("if_else_bodies")
        * (Pat("")/end_if_else_fn),

    if_stmt2 = con_if_begs/begin_if_fn * sp1
        * (-con_if_begs * Var("single_stmt") * (Pat("")/end_if_fn)
          + Var("if_else_bodies"))
        * (Pat("")/end_if_else_fn),

    while_stmt = Keyw("whilevarvarn") * sp1 * tok.rvar * sp1 * tok.rvar / "while (%1~=%2) do"
          * sp1 * Var("single_stmt") * lpeg.Cc("end")
        + Keyw("whilevarn") * sp1 * tok.rvar * sp1 * tok.define / "while (%1~=%2) do"
          * sp1 * Var("single_stmt") * lpeg.Cc("end"),

    stmt_common = Keyw("{") * sp1 * "}"  -- space separation of commands in CON is for a reason!
        + Keyw("{") * sp1 * stmt_list * sp1 * "}"
        + con_inner_command + Var("switch_stmt") + Var("while_stmt"),

    single_stmt = Stmt( lone_else^-1 * (Var("stmt_common") + Var("if_stmt")) ),
    single_stmt2 = Stmt( lone_else^-1 * (Var("stmt_common") + Var("if_stmt2")) ),

    -- a non-empty statement/command list
    stmt_list = Var("single_stmt") * (sp1 * Var("single_stmt"))^0,
}


local function setup_newlineidxs(contents)
    local newlineidxs = {}
    for i in string.gmatch(contents, "()\n") do
        newlineidxs[#newlineidxs+1] = i
    end
    if (#newlineidxs == 0) then
        -- try CR only (old Mac)
        for i in string.gmatch(contents, "()\r") do
            newlineidxs[#newlineidxs+1] = i
        end
--        if (#newlineidxs > 0) then print('CR-only lineends detected.') end
    end
    -- dummy newlines at beginning and end
    newlineidxs[#newlineidxs+1] = #contents+1
    newlineidxs[0] = 0

    return newlineidxs
end

---
local function do_flatten_codetab(code, intotab)
    for i=1,math.huge do
        local elt = code[i]

        if (type(elt)=="string") then
            intotab[#intotab+1] = elt
        elseif (type(elt)=="table") then
            do_flatten_codetab(elt, intotab)
        else
            assert(elt==nil)
            return
        end
    end
end

-- Return a "string buffer" table that can be table.concat'ed
-- to get the code string.
local function flatten_codetab(codetab)
    local tmpcode = {}
    do_flatten_codetab(codetab, tmpcode)
    return tmpcode
end

local function get_code_string(codetab)
    return table.concat(flatten_codetab(g_curcode), "\n")
end

function on.parse_begin()
    g_iflevel = 0
    g_ifelselevel = 0
    g_have_file[g_filename] = true

    -- set up new state
    -- TODO: pack into one "parser state" table?
    g_lastkw, g_lastkwpos, g_numerrors = nil, nil, 0
    g_recurslevel = g_recurslevel+1
end


---=== EXPORTED FUNCTIONS ===---

function parse(contents)  -- local
    -- save outer state
    local lastkw, lastkwpos, numerrors = g_lastkw, g_lastkwpos, g_numerrors
    local newlineidxs = g_newlineidxs

    on.parse_begin()

    g_newlineidxs = setup_newlineidxs(contents)

    addcodef("-- BEGIN %s", g_filename)

    local idx = lpeg.match(Grammar, contents)

    if (not idx) then
        printf("[%d] Match failed.", g_recurslevel)
        g_numerrors = inf
    elseif (idx == #contents+1) then
        if (g_numerrors ~= 0) then
            printf("[%d] Matched whole contents (%d errors).",
                   g_recurslevel, g_numerrors)
        elseif (g_recurslevel==0) then
            printf("[0] Matched whole contents.")
        end
    else
        local i, col = getlinecol(idx)
        local bi, ei = g_newlineidxs[i-1]+1, g_newlineidxs[i]-1

        printf("[%d] Match succeeded up to line %d, col %d (pos=%d, len=%d)",
               g_recurslevel, i, col, idx, #contents)
        g_numerrors = inf

--        printf("Line goes from %d to %d", bi, ei)
        local suffix = ""
        if (ei-bi > 76) then
            ei = bi+76
            suffix = " (...)"
        end
        printf("%s%s", string.sub(contents, bi, ei), suffix)

        if (g_lastkwpos) then
            i, col = getlinecol(g_lastkwpos)
            printf("Last keyword was at line %d, col %d: %s", i, col, g_lastkw)
        end
    end

    addcodef("-- END %s", g_filename)
    g_recurslevel = g_recurslevel-1

    -- restore outer state
    g_lastkw, g_lastkwpos = lastkw, lastkwpos
    g_numerrors = math.max(g_numerrors, numerrors)
    g_newlineidxs = newlineidxs
end

local function handle_cmdline_arg(str)
    if (str:sub(1,1)=="-") then
        if (#str == 1) then
            printf("Warning: input from stdin not supported")
        else
            local ok = false
            local kind = str:sub(2,2)

            if (kind=="W" and #str >= 3) then
                -- warnings
                local val = true
                local warnstr = str:sub(3)

                if (#warnstr >= 4 and warnstr:sub(1,3)=="no-") then
                    val = false
                    warnstr = warnstr:sub(4)
                end

                if (type(g_warn[warnstr])=="boolean") then
                    g_warn[warnstr] = val
                    ok = true
                end
            elseif (str:sub(2,4)=="fno") then
                -- Disable printing code.
                if (#str >= 5 and str:sub(5)=="=onlycheck") then
                    g_cgopt["no"] = "onlycheck"
                    ok = true
                else
                    g_cgopt["no"] = true
                    ok = true
                end
            elseif (kind=="I" and #str >= 3) then
                -- default directory (only ONCE, not search path)
                g_defaultDir = str:sub(3)
                ok = true
            end

            if (not ok) then
                printf("Warning: Unrecognized option %s", str)
            end
        end

        return true
    end
end

local function reset_all()
    reset_labels()
    reset_gamedata()
    reset_codegen()
end

local function print_on_failure(msg)
    if (g_lastkwpos ~= nil) then
        printf("LAST KEYWORD POSITION: %s, %s", linecolstr(g_lastkwpos), g_lastkw)
    end
    print(msg)
end

if (string.dump) then
    -- running stand-alone

    local i = 1
    while (arg[i]) do
        if (handle_cmdline_arg(arg[i])) then
            table.remove(arg, i)
        else
            i = i+1
        end
    end

    for argi=1,#arg do
        local filename = arg[argi]

        reset_all()

        g_directory = filename:match("(.*/)") or ""
        filename = filename:sub(#g_directory+1, -1)

        -- NOTE: xpcall isn't useful here since the traceback won't give us
        -- anything inner to the lpeg.match call
        local ok, msg = pcall(do_include_file, g_directory, filename)
        -- ^v Swap commenting (comment top, uncomment bottom line) to get backtraces
--        local ok, msg = true, do_include_file(g_directory, filename)

        if (not ok) then
            print_on_failure(msg)
        end

        if (not (g_cgopt["no"]==true)) then
            local onlycheck = (g_cgopt["no"] == "onlycheck")
            local io = require("io")
            local file = onlycheck and io.stdout or io.stderr

            local code = get_code_string(g_curcode)
            local func, errmsg = loadstring(code, "CON")

            file:write(format("-- GENERATED CODE for \"%s\":\n", filename))
            if (func == nil) then
                file:write(format("-- (invalid Lua code: %s)\n", errmsg))
            end

            if (not onlycheck) then
                file:write(code)
                file:write("\n")
            end
        end
    end
else
    -- running from EDuke32
    function compile(filenames)
        -- TODO: pathsearchmode=1 set in G_CompileScripts

        reset_all()

        for _, fname in ipairs(filenames) do
            local ok, msg = pcall(do_include_file, "", fname)
            if (not ok or g_numerrors > 0) then
                if (not ok) then
                    -- Unexpected error in the Lua code (i.e. a bug here).
                    print_on_failure(msg)
                end
                return nil
            end
        end

        return get_code_string(g_curcode)
    end
end