strict.lua
require 'debug' local getinfo, error, rawset, rawget = debug.getinfo, error, rawset, rawget
local strict = {}
local function what ()
local d = getinfo(3, "S")
return d and d.what or "C"
end
function strict.module (name,mod,predeclared)
local mt, old_newindex, old_index, old_index_type, global, closed
if predeclared then
global = predeclared.__global
closed = predeclared.__closed
end
if type(mod) == 'table' then
mt = getmetatable(mod)
if mt and rawget(mt,'__declared') then return end else
mod = {}
end
if mt == nil then
mt = {}
setmetatable(mod, mt)
else
old_newindex = mt.__newindex
old_index = mt.__index
old_index_type = type(old_index)
end
mt.__declared = predeclared or {}
mt.__newindex = function(t, n, v)
if old_newindex then
old_newindex(t, n, v)
if rawget(t,n)~=nil then return end
end
if not mt.__declared[n] then
if global then
local w = what()
if w ~= "main" and w ~= "C" then
error("assign to undeclared global '"..n.."'", 2)
end
end
mt.__declared[n] = true
end
rawset(t, n, v)
end
mt.__index = function(t,n)
if not mt.__declared[n] and what() ~= "C" then
if old_index then
if old_index_type == "table" then
local fallback = old_index[n]
if fallback ~= nil then
return fallback
end
else
local res = old_index(t, n)
if res then return res end
end
end
local msg = "variable '"..n.."' is not declared"
if name then
msg = msg .. " in '"..name.."'"
end
error(msg, 2)
end
return rawget(t, n)
end
return mod
end
function strict.make_all_strict (T)
for k,v in pairs(T) do
if type(v) == 'table' and v ~= T then
strict.module(k,v)
end
end
end
function strict.closed_module (mod,name)
local M = {}
mod = mod or {}
local mt = getmetatable(mod)
if not mt then
mt = {}
setmetatable(mod,mt)
end
mt.__newindex = function(t,k,v)
M[k] = v
end
return strict.module(name,M)
end
if not rawget(_G,'PENLIGHT_NO_GLOBAL_STRICT') then
strict.module(nil,_G,{_PROMPT=true,__global=true})
end
return strict