-- A module of LSL stuffs.
-- TODO - currently there is a constants.lsl file.  Move it into here.
--   It contains LSL constants and ll*() functions stubs.
--   The compiler compiles that into a LSL_Scripts structure at startup,
--   then uses that for function and variable lookups, as well as looking up in the current script.
--   I can run this at compiler startup time, then iterate through the LSL table from C to generate that LSL_Script structure.
--[[
Have an array of functions and argument types.
Compiler startup writes a short script that loads this module as normal, then calls the special "gimme the LSL" function.
  The function runs through the array, calling back to C, passing each function definition.
  It also runs through the constants, calling back to C, passing each constant type, name, and value.
  In both cases, it could just combine them all (variables and functions together) into one big string blob to pass to the lexer+parser.
Hook up the metatable _call method to check if the function is in the array, then pass it to OpenSim.
  The array includes any return type, so _call knows if it has to wait for the reply.
  So the function array should have some structure, to be able to tell the function name, and the various types.
]]

-- Using a module means it gets compiled each time?  Maybe not if I can use bytecode files.  Perhaps LuaJIT caches these?
--   Does not seem to be slowing it down noticably, but that might change once the stubs are filled out.

-- Use it like this -
-- local _LSL = require 'LSL'

--[[ From http://lua-users.org/wiki/LuaModuleFunctionCritiqued
A related note on C code: The luaL_register [9] function in C is
somewhat analogous to the module function in Lua, so luaL_register
shares similar problems, at least when a non-NULL libname is used.
Furthermore, the luaL_newmetatable/luaL_getmetatable/luaL_checkudata
functions use a C string as a key into the global registry. This poses
some potential for name conflicts--either because the modules were
written by different people or because they are different versions of
the same module loaded simultaneously. To address this, one may instead
use a lightuserdata (pointer to variable of static linkage to ensure
global uniqueness) for this key or store the metatable as an
upvalue--either way is a bit more efficient and less error prone.
]]

-- http://www.lua.org/pil/15.4.html looks useful.
-- http://www.lua.org/pil/15.5.html the last part about autoloading functions might be useful.

local LSL = {};
local SID = "";


-- Debugging aids

-- Functions to print tables.
local print_table, print_table_start;

function print_table_start(table, space, name)
  print(space .. name .. ": ");
  print(space .. "{");
  print_table(table, space .. "  ");
  print(space .. "}");
end

function print_table(table, space)
  for k, v in pairs(table) do
    if type(v) == "table" then
      print_table_start(v, space, k);
    elseif type(v) == "string" then
      print(space .. k .. ': "' .. v .. '";')
    else
      print(space .. k .. ": " .. v .. ";")
    end
  end
end

function msg(...)
  print(SID, ...)  -- The comma adds a tab, fancy that.  B-)
end

-- LSL function and constant creation stuff.

local function newConst(Type, name, value)
  LSL[name] = value
  return { Type = Type, name = name }
end

local function newFunc(Type, name, ... )
    return { Type = Type, name = name, args = ... }
end

local functions =
{
  newFunc("key", "llAvatarOnSitTarget"),
  newFunc("list", "llGetAnimationList", "key"),
}

local constants =
{
  newConst("float", "PI", 3.14159265358979323846264338327950),
}


-- LSL constants.

LSL.PI					= 3.14159265358979323846264338327950;
LSL.PI_BY_TWO				= LSL.PI / 2;		-- 1.57079632679489661923132169163975
LSL.TWO_PI				= LSL.PI * 2;		-- 6.28318530717958647692528676655900
LSL.DEG_TO_RAD				= LSL.PI / 180.0;	-- 0.01745329252
LSL.RAD_TO_DEG				= 180.0 / LSL.PI;	-- 57.2957795131
LSL.SQRT2				= 1.4142135623730950488016887242097;

LSL.CHANGED_INVENTORY			= 0x001;
LSL.CHANGED_COLOR			= 0x002;
LSL.CHANGED_SHAPE			= 0x004;
LSL.CHANGED_SCALE			= 0x008;
LSL.CHANGED_TEXTURE			= 0x010;
LSL.CHANGED_LINK			= 0x020;
LSL.CHANGED_ALLOWED_DROP		= 0x040;
LSL.CHANGED_OWNER			= 0x080;
LSL.CHANGED_REGION			= 0x100;
LSL.CHANGED_TELEPORT			= 0x200;
LSL.CHANGED_REGION_START		= 0x400;
LSL.CHANGED_MEDIA			= 0x800;

LSL.DEBUG_CHANNEL			= 2147483647;
LSL.PUBLIC_CHANNEL			= 0;

LSL.INVENTORY_ALL			= -1;
LSL.INVENTORY_NONE			= -1;
LSL.INVENTORY_TEXTURE			= 0;
LSL.INVENTORY_SOUND			= 1;
LSL.INVENTORY_LANDMARK			= 3;
LSL.INVENTORY_CLOTHING			= 5;
LSL.INVENTORY_OBJECT			= 6;
LSL.INVENTORY_NOTECARD			= 7;
LSL.INVENTORY_SCRIPT			= 10;
LSL.INVENTORY_BODYPART			= 13;
LSL.INVENTORY_ANIMATION			= 20;
LSL.INVENTORY_GESTURE			= 21;

LSL.ALL_SIDES				= -1;
LSL.LINK_SET				= -1;
LSL.LINK_ROOT				= 1;
LSL.LINK_ALL_OTHERS			= -2;
LSL.LINK_ALL_CHILDREN			= -3;
LSL.LINK_THIS				= -4;

LSL.PERM_ALL				= 0x7FFFFFFF;
LSL.PERM_COPY				= 0x00008000;
LSL.PERM_MODIFY				= 0x00004000;
LSL.PERM_MOVE				= 0x00080000;
LSL.PERM_TRANSFER			= 0x00002000;
LSL.MASK_BASE				= 0;
LSL.MASK_OWNER				= 1;
LSL.MASK_GROUP				= 2;
LSL.MASK_EVERYONE			= 3;
LSL.MASK_NEXT				= 4;
LSL.PERMISSION_DEBIT			= 0x0002;
LSL.PERMISSION_TAKE_CONTROLS		= 0x0004;
LSL.PERMISSION_TRIGGER_ANIMATION	= 0x0010;
LSL.PERMISSION_ATTACH			= 0x0020;
LSL.PERMISSION_CHANGE_LINKS		= 0x0080;
LSL.PERMISSION_TRACK_CAMERA		= 0x0400;
LSL.PERMISSION_CONTRAL_CAMERA		= 0x0800;

LSL.AGENT			 	= 0x01;
LSL.ACTIVE			 	= 0x02;
LSL.PASSIVE			 	= 0x04;
LSL.SCRIPTED		 		= 0x08;

LSL.OBJECT_UNKNOWN_DETAIL		= -1;

LSL.PRIM_BUMP_SHINY			= 19;
LSL.PRIM_COLOR				= 18;
LSL.PRIM_FLEXIBLE			= 21;
LSL.PRIM_FULLBRIGHT			= 20;
LSL.PRIM_GLOW				= 25;
LSL.PRIM_MATERIAL			= 2;
LSL.PRIM_PHANTOM			= 5;
LSL.PRIM_PHYSICS			= 3;
LSL.PRIM_POINT_LIGHT			= 23;
LSL.PRIM_POSITION			= 6;
LSL.PRIM_ROTATION			= 8;
LSL.PRIM_SIZE				= 7;
LSL.PRIM_TEMP_ON_REZ			= 4;
LSL.PRIM_TYPE				= 9;
LSL.PRIM_TYPE_OLD			= 1;
LSL.PRIM_TEXGEN				= 22;
LSL.PRIM_TEXTURE			= 17;
LSL.PRIM_TEXT				= 26;

LSL.PRIM_BUMP_NONE			= 0;
LSL.PRIM_BUMP_BRIGHT			= 1;
LSL.PRIM_BUMP_DARK			= 2;
LSL.PRIM_BUMP_WOOD			= 3;
LSL.PRIM_BUMP_BARK			= 4;
LSL.PRIM_BUMP_BRICKS			= 5;
LSL.PRIM_BUMP_CHECKER			= 6;
LSL.PRIM_BUMP_CONCRETE			= 7;
LSL.PRIM_BUMP_TILE			= 8;
LSL.PRIM_BUMP_STONE			= 9;
LSL.PRIM_BUMP_DISKS			= 10;
LSL.PRIM_BUMP_GRAVEL			= 11;
LSL.PRIM_BUMP_BLOBS			= 12;
LSL.PRIM_BUMP_SIDING			= 13;
LSL.PRIM_BUMP_LARGETILE			= 14;
LSL.PRIM_BUMP_STUCCO			= 15;
LSL.PRIM_BUMP_SUCTION			= 16;
LSL.PRIM_BUMP_WEAVE			= 17;

LSL.PRIM_HOLE_DEFAULT			= 0;
LSL.PRIM_HOLE_CIRCLE			= 16;
LSL.PRIM_HOLE_SQUARE			= 32;
LSL.PRIM_HOLE_TRIANGLE			= 48;

LSL.PRIM_MATERIAL_STONE			= 0;
LSL.PRIM_MATERIAL_METAL			= 1;
LSL.PRIM_MATERIAL_GLASS			= 2;
LSL.PRIM_MATERIAL_WOOD			= 3;
LSL.PRIM_MATERIAL_FLESH			= 4;
LSL.PRIM_MATERIAL_PLASTIC		= 5;
LSL.PRIM_MATERIAL_RUBBER		= 6;
LSL.PRIM_MATERIAL_LIGHT			= 7;

LSL.PRIM_SCULPT_TYPE_SPHERE		= 1;
LSL.PRIM_SCULPT_TYPE_TORUS		= 2;
LSL.PRIM_SCULPT_TYPE_PLANE		= 3;
LSL.PRIM_SCULPT_TYPE_CYLINDER		= 4;
LSL.PRIM_SCULPT_TYPE_MESH		= 5;
LSL.PRIM_SCULPT_TYPE_MIMESH		= 6;

LSL.PRIM_SHINY_NONE			= 0;
LSL.PRIM_SHINY_LOW			= 1;
LSL.PRIM_SHINY_MEDIUM			= 2;
LSL.PRIM_SHINY_HIGH			= 3;

LSL.PRIM_TYPE_BOX			= 0;
LSL.PRIM_TYPE_CYLINDER			= 1;
LSL.PRIM_TYPE_PRISM			= 2;
LSL.PRIM_TYPE_SPHERE			= 3;
LSL.PRIM_TYPE_TORUS			= 4;
LSL.PRIM_TYPE_TUBE			= 5;
LSL.PRIM_TYPE_RING			= 6;
LSL.PRIM_TYPE_SCULPT			= 7;

LSL_RC_GET_NORMAL			= 1;
LSL_RC_GET_ROOT_KEY			= 2;
LSL_RC_GET_LINK_NUM			= 4;
LSL_RC_REJECT_AGENTS			= 1;
LSL_RC_REJECT_PHYSICAL			= 2;
LSL_RC_REJECT_NONPHYSICAL		= 4;
LSL_RC_REJECT_LAND			= 8;
LSL.RC_REJECT_TYPES			= 0;
LSL.RC_DETECT_PHANTOM			= 1;
LSL.RC_DATA_FLAGS			= 2;
LSL.RC_MAX_HITS				= 3;
LSL.RCERR_UNKNOWN			= -1;
LSL.RCERR_SIM_PERF_LOW			= -2;
LSL.RCERR_CAST_TIME_EXCEEDED		= -3;

LSL.STATUS_OK				= 0;
LSL.STATUS_MALFORMED_PARAMS		= 1000;
LSL.STATUS_TYPE_MISMATCH		= 1001;
LSL.STATUS_BOUNDS_ERROR			= 1002;
LSL.STATUS_NOT_FOUND			= 1003;
LSL.STATUS_NOT_SUPPORTED		= 1004;
LSL.STATUS_INTERNAL_ERROR		= 1999;
LSL.STATUS_WHITELIST_FAILED		= 2001;

LSL.STRING_TRIM				= 3;
LSL.STRING_TRIM_HEAD			= 1;
LSL.STRING_TRIM_TAIL			= 2;

LSL.TRUE				= 1;
LSL.FALSE				= 0;

LSL.TYPE_INTEGER			= 1;
LSL.TYPE_FLOAT				= 2;
LSL.TYPE_STRING				= 3;
LSL.TYPE_KEY				= 4;
LSL.TYPE_VECTOR				= 5;
LSL.TYPE_ROTATION			= 6;
LSL.TYPE_INVALID			= 0;

LSL.NULL_KEY				= "00000000-0000-0000-0000-000000000000";
LSL.EOF					= "\n\n\n";

LSL.ZERO_ROTATION			= {x=0.0, y=0.0, z=0.0, s=1.0};
LSL.ZERO_VECTOR				= {x=0.0, y=0.0, z=0.0};

-- TODO - Temporary dummy variables to got vector and rotation thingies to work for now.

LSL.s					= 1.0;
LSL.x					= 0.0;
LSL.y					= 0.0;
LSL.z					= 0.0;

-- ll*() function stubs.


-- LSL avatar functions

function --[[key]]	LSL.llAvatarOnSitTarget() return LSL.NULL_KEY end;
function --[[list]]	LSL.llGetAnimationList(--[[key]] id) return {} end;
function --[[integer]] 	LSL.llGetPermissions() return 0 end;
function --[[key]]	LSL.llGetPermissionsKey() return LSL.NULL_KEY end;
function --[[string]]	LSL.llKey2Name(--[[key]] avatar) return "" end;
function 		LSL.llRequestPermissions(--[[key]] avatar,--[[integer]] perms) end;
function --[[integer]] 	LSL.llSameGroup(--[[key]] avatar) return 0 end;
function 		LSL.llStartAnimation(--[[string]] anim) end;
function 		LSL.llStopAnimation(--[[string]] anim) end;
function 		LSL.llUnSit(--[[key]] avatar) end;


-- LSL collision / detect / sensor functions

function --[[key]]	LSL.llDetectedGroup(--[[integer]] index) return LSL.NULL_KEY end;
function --[[key]]	LSL.llDetectedKey(--[[integer]] index) return LSL.NULL_KEY end;


-- LSL communications functions

function 		LSL.llDialog(--[[key]] avatar, --[[string]] caption, --[[list]] arseBackwardsMenu,--[[integer]] channel) end;
function --[[integer]] 	LSL.llListen(--[[integer]] channel, --[[string]] name, --[[key]] id, --[[string]] msg) return 0 end;
function 		LSL.llListenRemove(--[[integer]] handle) end;
function 		LSL.llOwnerSay(--[[string]] text) msg("Owner say: " .. text); end;
function 		LSL.llSay(--[[integer]] channel, --[[string]] text) msg("Channel " .. channel .. " say: " .. text); end;
function 		LSL.llShout(--[[integer]] channel, --[[string]] text) msg("Channel " .. channel .. " shout: " .. text); end;
function 		LSL.llWhisper(--[[integer]] channel, --[[string]] text) msg("Channel " .. channel .. " whisper: " .. text); end;

function 		LSL.llMessageLinked(--[[integer]] link,--[[integer]] num, --[[string]] text, --[[key]] aKey) end;


-- LSL inventory functions.

function --[[string]]	LSL.llGetInventoryName(--[[integer]] tyPe,--[[integer]] index) return "" end;
function --[[integer]] 	LSL.llGetInventoryNumber(--[[integer]] tyPe) return 0 end;
function --[[integer]] 	LSL.llGetInventoryType(--[[string]] name) return LSL.INVENTORY_SCRIPT end;
function --[[key]]	LSL.llGetNotecardLine(--[[string]] name,--[[integer]] index) return LSL.NULL_KEY end;
function 		LSL.llRezAtRoot(--[[string]] name, --[[vector]] position, --[[vector]] velocity, --[[rotation]] rot,--[[integer]] channel) end;
function 		LSL.llRezObject(--[[string]] name, --[[vector]] position, --[[vector]] velocity, --[[rotation]] rot,--[[integer]] channel) end;


-- LSL list functions.

function --[[list]]	LSL.llCSV2List(--[[string]] text) return {} end;
function --[[list]]	LSL.llDeleteSubList(--[[list]] l,--[[integer]] start,--[[integer]] eNd)
  local result = {}
  local x = 1

  -- Deal with the impedance mismatch.
  start = start + 1
  eNd   = eNd + 1
  for i = 1,#l do
    if      i < start then result[x] = l[i];  x = x + 1
    elseif  i > eNd   then result[x] = l[i];  x = x + 1
    end
  end

  return result
end

function --[[string]]	LSL.llDumpList2String(--[[list]] l, --[[string]] separator)
  local result = ""
  for i = 1,#l do
    if "" ~= result then result = result .. separator end
    result = result .. l[i]
  end
  return result
end

function --[[integer]] 	LSL.llGetListLength(--[[list]] l)
  return #l
end

function --[[string]]	LSL.llList2CSV(--[[list]] l)
  return LSL.llDumpList2String(l, ",")
end

function --[[float]] 	LSL.llList2Float(--[[list]] l,--[[integer]] index)
  local result = tonumber(l[index])
  if nil == result then result = 0.0 end
  return result
end

function --[[integer]] 	LSL.llList2Integer(--[[list]] l,--[[integer]] index)
  local result = tonumber(l[index+1])
  if nil == result then result = 0 end
  return result
end

function --[[key]]	LSL.llList2Key(--[[list]] l,--[[integer]] index)
  local result = l[index+1]
  if result then return "" .. result else return LSL.NULL_KEY end
end

function --[[list]]	LSL.llList2List(--[[list]] l,--[[integer]] start,--[[integer]] eNd)
  local result = {}
  local x = 1

  --[[ TODO -
Using negative numbers for start and/or end causes the index to count backwards from the length of the list, so 0, -1 would capture the entire list.
If start is larger than end the list returned is the exclusion of the entries, so 6, 4 would give the entire list except for the 5th entry.
    ]]

  -- Deal with the impedance mismatch.
  start = start + 1
  eNd   = eNd + 1
  for i = 1,#l do
    if      i >= start then result[x] = l[i];  x = x + 1
    elseif  i <= eNd   then result[x] = l[i];  x = x + 1
    end
  end

  return result
end

function --[[string]]	LSL.llList2String(--[[list]] l,--[[integer]] index)
  local result = l[index+1]
  if result then return "" .. result else return "" end
end

function --[[rotation]]	LSL.llList2Rotation(--[[list]] l,--[[integer]] index)
  local result = l[index+1]
  if nil == result then result = LSL.ZERO_ROTATION end
  -- TODO - check if it's not an actual rotation, then return LSS.ZERO_ROTATION
  return result
end

function --[[vector]]	LSL.llList2Vector(--[[list]] l,--[[integer]] index)
  local result = l[index+1]
  if nil == result then result = LSL.ZERO_VECTOR end
  -- TODO - check if it's not an actual rotation, then return LSS.ZERO_VECTOR
  return result
end

function --[[integer]] 	LSL.llListFindList(--[[list]] l, --[[list]] l1) return 0 end;
function --[[list]]	LSL.llListInsertList(--[[list]] l, --[[list]] l1,--[[integer]] index)
  local result = {}
  local x = 1
  local y
  for i = 1,index do
    result[x] = l[i]
    x = x + 1
  end
  y = x
  for i = 1,#ll do
    result[x] = ll[i]
    x = x + 1
  end
  for i = y,#l do
    result[x] = l[i]
    x = x + 1
  end
  return result
end

function --[[list]]	LSL.llListReplaceList(--[[list]] l, --[[list]] part,--[[integer]] start,--[[integer]] eNd)
  local result = {}
  local x = 1
  local y
  for i = 1,index do
    result[x] = l[i]
    x = x + 1
  end
  for i = 1,#part do
    result[x] = part[i]
    x = x + 1
  end
  for i = index,#l do
    result[x] = l[i]
    x = x + 1
  end
  return result
end

function --[[list]]	LSL.llListSort(--[[list]] l,--[[integer]] stride,--[[integer]] ascending)
  local result = {}

  -- TODO - Deal with stride and ascending.
  for i = 1,#l do
    result[x] = l[i];  x = x + 1
  end
  table.sort(result)

  return result
end

function --[[list]]	LSL.llParseString2List(--[[string]] In, --[[list]] l, --[[list]] l1) return {} end;
function --[[list]]	LSL.llParseStringKeepNulls(--[[string]] In, --[[list]] l, --[[list]] l1) return {} end;


-- LSL math functions

function --[[rotation]]	LSL.llEuler2Rot(--[[vector]] vec) return LSL.ZERO_ROTATION end;
function --[[float]]	LSL.llFrand(--[[float]] max) return 0.0 end;
function --[[float]]	LSL.llPow(--[[float]] number,--[[float]] places) return 0.0 end;
function --[[vector]]	LSL.llRot2Euler(--[[rotation]] rot)  return LSL.ZERO_VECTOR end;
function --[[integer]]	LSL.llRound(--[[float]] number) return 0 end;


-- LSL media functions

function 		LSL.llPlaySound(--[[string]] name,--[[float]] volume) end;


-- LSL object / prim functions

function 		LSL.llDie() end;
function --[[key]]	LSL.llGetKey() return LSL.NULL_KEY end;
function --[[integer]] 	LSL.llGetLinkNumber() return 0 end;
function --[[string]]	LSL.llGetObjectDesc() return "" end;
function --[[string]]	LSL.llGetObjectName() return "" end;
function --[[key]]	LSL.llGetOwner() return LSL.NULL_KEY end;
function 		LSL.llSetObjectDesc(--[[string]] text) end;
function 		LSL.llSetObjectName(--[[string]] text) end;
function 		LSL.llSetPrimitiveParams(--[[list]] params) end;
function 		LSL.llSetSitText(--[[string]] text) end;
function 		LSL.llSetText(--[[string]] text, --[[vector]] colour,--[[float]] alpha) end;
function 		LSL.llSitTarget(--[[vector]] pos, --[[rotation]] rot) end;


-- LSL rotation / scaling / translation functions

function --[[vector]]	LSL.llGetPos() return LSL.ZERO_VECTOR end;
function --[[rotation]]	LSL.llGetRot() return LSL.ZERO_ROTATION end;
function 		LSL.llSetPos(--[[vector]] pos) end;
function 		LSL.llSetRot(--[[rotation]] rot) end;
function 		LSL.llSetScale(--[[vector]] scale) end;


-- LSL script functions

function --[[integer]] 	LSL.llGetFreeMemory() return 0 end;
function --[[string]]	LSL.llGetScriptName() return "" end;
function 		LSL.llResetOtherScript(--[[string]] name) msg("llResetOtherScript(" .. name .. ")") end;
function 		LSL.llResetScript() end;
function 		LSL.llSetScriptState(--[[string]] name,--[[integer]] running) msg("llSetScriptState(" .. name .. "," .. running .. ")") end;


-- LSL string functions

function --[[string]]	LSL.llGetSubString(--[[string]] text,--[[integer]] start,--[[integer]] eNd) return "" end;
function --[[integer]] 	LSL.llStringLength(--[[string]] text) return 0 end;
function --[[string]]	LSL.llStringTrim(--[[string]] text,--[[integer]] tyPe) return "" end;
function --[[integer]] 	LSL.llSubStringIndex(--[[string]] text, --[[string]] sub) return 0 end;


-- LSL texture functions

function --[[float]] 	LSL.llGetAlpha(--[[integer]] side) return 0.0 end;
function 		LSL.llSetAlpha(--[[float]] alpha,--[[integer]] side) end;
function 		LSL.llSetColor(--[[vector]] colour,--[[integer]] side) end;


-- LSL time functions

function --[[float]] 	LSL.llGetTime() return 0.0 end;
function 		LSL.llResetTime() end;
function 		LSL.llSetTimerEvent(--[[float]] seconds) end;
function 		LSL.llSleep(--[[float]] seconds) msg("llSleep(" .. seconds .. ")") end;



-- Crements stuff.

function LSL.preDecrement(name) _G[name] = _G[name] - 1; return _G[name]; end;
function LSL.preIncrement(name) _G[name] = _G[name] + 1; return _G[name]; end;
function LSL.postDecrement(name) local temp = _G[name]; _G[name] = _G[name] - 1; return temp; end;
function LSL.postIncrement(name) local temp = _G[name]; _G[name] = _G[name] + 1; return temp; end;


-- State stuff

local currentState = {}
local running = true
local paused = false

-- Stuff called from the wire protocol has to be global, but I think this means just global to this file.
function stop() paused = true  end
function quit()  running = false  end

function LSL.stateChange(x)
  if currentState ~= x then  -- Changing to the same state is a NOP.
    -- TODO - Should clear out pending events, except timer()
    -- Also forget about any event setup that needs setting up via some ll*() function, except timer().
    if nil ~= currentState.state_exit then
      currentState.state_exit();
    end
    currentState = x;
    --[[  Never return to the current states event handler.  In theory.  lol
	  Notably, it's not actually legal to do a state change from a function, only from handlers.
	  There is a hack though, but it's unsupported, so I don't have to worry about it so much.

	  Write out "state new;" as "return _LSL.stateChange(newState);", with stateChange() returning new.state_entry()) which will force two tail calls.

	  The caller of stateChange() might be a function rather than an event handler.
	  Which will return to the event handler (possibly via other nested function calls) as if the state never changed.
	  http://lslwiki.net/lslwiki/wakka.php?wakka=FunctionStateChangeHack seems to imply that this is exactly what LSL does.
	  Soooo, this might actually work perfectly.
	  Except for one minor quirk, as that page shows - only the top level function's state sticks, unless the handler does one to, then the handlers one overrides things.
	  Which I can probably ignore anyway, as this entire calling states within functions thing is an unsupported hack.
      ]]
    if nil ~= currentState.state_entry then
      return currentState.state_entry();
    end
  end
end;

function LSL.mainLoop(sid, x)
  local status, errorMsg = luaproc.newchannel(sid)
  local result

  SID = sid

  if not status then
    msg("Can't open the luaproc channel " .. sid .. "  ERROR MESSAGE: " .. errorMsg)
    return
  end

  LSL.stateChange(x);

  -- Need a FIFO queue of incoming events.  Which will be in the C main thread, coz that's listening on the socket for us.
  -- The ecore_con stuff ends up being a sorta FIFO queue of the commands coming from OpenSim.
  -- Plus, I think the luaproc message system manages a FIFO queue for us as well.
  -- Might still need one.  lol

  while running do
    local message = luaproc.receive(sid)
    if message then
      if paused then
	if "start()" == message then paused = false  end
      else
	result, errorMsg = loadstring(message)  -- "The environment of the returned function is the global environment."  Though normally, a function inherits it's environment from the function creating it.  Which is what we want.  lol
	if nil == result then
	  msg("Not a valid event: " .. message .. "  ERROR MESSAGE: " .. errorMsg)
	else
	  -- Set the functions environment to ours, for the protection of the script, coz loadstring sets it to the global environment instead.
	  -- TODO - On the other hand, we will need the global environment when we call event handlers.  So we should probably stash it around here somewhere.
	  setfenv(result, getfenv(1))
	  status, result = pcall(result)
	  if not status then
	    msg("Error from event: " .. message .. "  ERROR MESSAGE: " .. result)
	  elseif result then
	    status, errorMsg = luaproc.send(sid, result)
	    if not status then
	      msg("Error sending results from event: " .. message .. "  ERROR MESSAGE: " .. errorMsg)
	    end
	  end
	end
      end
    end
  end
end


-- Typecasting stuff.

function LSL.floatTypecast(x)
  local temp = tonumber(x)
  if nil == temp then temp = 0 end
  return temp;
end

function LSL.integerTypecast(x)
  local temp = tonumber(x)
  if nil == temp then temp = 0 end
  return temp;
end

function LSL.keyTypecast(x)
  return "" .. x;
end

function LSL.listTypecast(x)
  return {x};
end

function LSL.rotationTypecast(x)
   return x;
end

function LSL.stringTypecast(x)
   return "" .. x;
end

function LSL.vectorTypecast(x)
   return x;
end


return LSL;