[LUA] get table

local val_to_str, key_to_str, tabletostring
local char, byte, gsub, match, sub, find =
    string.char, string.byte, string.gsub, string.match, string.sub, string.find
local insert, concat = table.insert, table.concat

function val_to_str ( v )
    if "string" == type( v ) then
        v = gsub( v, "\n", "\\n" )
        if match( gsub(v,"[^'\"]",""), '^"+$' ) then
            return "'" .. v .. "'"
        end
        return '"' .. gsub(v,'"', '\\"' ) .. '"'
    else
        return "table" == type( v ) and tabletostring( v ) or
            tostring( v )
    end
end

function key_to_str ( k )
    if "string" == type( k ) and match( k, "^[_%a][_%a%d]*$" ) then
        return k
    else
        return "[" .. val_to_str( k ) .. "]"
    end
end

function tabletostring( tbl )
    local result, done = {}, {}
    for k, v in ipairs( tbl ) do
        insert( result, val_to_str( v ) )
        done[ k ] = true
    end
    for k, v in pairs( tbl ) do
        if not done[ k ] then
            insert( result,
            key_to_str( k ) .. "=" .. val_to_str( v ) )
        end
    end
    return "{" .. concat( result, "," ) .. "}"
end

if _ARGS == '' then return 'error.' end
local tab = _ENV[_ARGS]
local bool = false
if _ARGS == '_ENV' then tab = _ENV; bool = true end
if type(tab) ~= 'table' then return 'error.' end
return (bool and '_ENV' or _ARGS) .. ' = ' .. tabletostring(tab)