Test version

mesecons_sandbox/sandbox/helpers.lua

@@ -0,0 +1,187 @@
+--------------------------------------------------------------------------------
+-- Localize functions to avoid table lookups (better performance).
+local string_sub, string_find = string.sub, string.find
+
+--------------------------------------------------------------------------------
+local function basic_dump(o)
+	local tp = type(o)
+	if tp == "number" then
+		return tostring(o)
+	elseif tp == "string" then
+		return string.format("%q", o)
+	elseif tp == "boolean" then
+		return tostring(o)
+	elseif tp == "nil" then
+		return "nil"
+	-- Uncomment for full function dumping support.
+	-- Not currently enabled because bytecode isn't very human-readable and
+	-- dump's output is intended for humans.
+	--elseif tp == "function" then
+	--	return string.format("loadstring(%q)", string.dump(o))
+	else
+		return string.format("<%s>", tp)
+	end
+end
+
+local keywords = {
+	["and"] = true,
+	["break"] = true,
+	["do"] = true,
+	["else"] = true,
+	["elseif"] = true,
+	["end"] = true,
+	["false"] = true,
+	["for"] = true,
+	["function"] = true,
+	["goto"] = true,  -- Lua 5.2
+	["if"] = true,
+	["in"] = true,
+	["local"] = true,
+	["nil"] = true,
+	["not"] = true,
+	["or"] = true,
+	["repeat"] = true,
+	["return"] = true,
+	["then"] = true,
+	["true"] = true,
+	["until"] = true,
+	["while"] = true,
+}
+local function is_valid_identifier(str)
+	if not string_find("^[a-zA-Z_][a-zA-Z0-9_]*$") or keywords[str] then
+		return false
+	end
+	return true
+end
+
+--------------------------------------------------------------------------------
+-- Dumps values in a line-per-value format.
+-- For example, {test = {"Testing..."}} becomes:
+--   _["test"] = {}
+--   _["test"][1] = "Testing..."
+-- This handles tables as keys and circular references properly.
+-- It also handles multiple references well, writing the table only once.
+-- The dumped argument is internal-only.
+
+local function dump2(o, name, dumped)
+	name = name or "_"
+	-- "dumped" is used to keep track of serialized tables to handle
+	-- multiple references and circular tables properly.
+	-- It only contains tables as keys.  The value is the name that
+	-- the table has in the dump, eg:
+	-- {x = {"y"}} -> dumped[{"y"}] = '_["x"]'
+	dumped = dumped or {}
+	if type(o) ~= "table" then
+		return string.format("%s = %s\n", name, basic_dump(o))
+	end
+	if dumped[o] then
+		return string.format("%s = %s\n", name, dumped[o])
+	end
+	dumped[o] = name
+	-- This contains a list of strings to be concatenated later (because
+	-- Lua is slow at individual concatenation).
+	local t = {}
+	for k, v in pairs(o) do
+		local keyStr
+		if type(k) == "table" then
+			if dumped[k] then
+				keyStr = dumped[k]
+			else
+				-- Key tables don't have a name, so use one of
+				-- the form _G["table: 0xFFFFFFF"]
+				keyStr = string.format("_G[%q]", tostring(k))
+				-- Dump key table
+				t[#t + 1] = dump2(k, keyStr, dumped)
+			end
+		else
+			keyStr = basic_dump(k)
+		end
+		local vname = string.format("%s[%s]", name, keyStr)
+		t[#t + 1] = dump2(v, vname, dumped)
+	end
+	return string.format("%s = {}\n%s", name, table.concat(t))
+end
+
+--------------------------------------------------------------------------------
+-- This dumps values in a one-statement format.
+-- For example, {test = {"Testing..."}} becomes:
+-- [[{
+-- 	test = {
+-- 		"Testing..."
+-- 	}
+-- }]]
+-- This supports tables as keys, but not circular references.
+-- It performs poorly with multiple references as it writes out the full
+-- table each time.
+-- The indent field specifies a indentation string, it defaults to a tab.
+-- Use the empty string to disable indentation.
+-- The dumped and level arguments are internal-only.
+
+function dump(o, indent, nested, level)
+	local t = type(o)
+	if not level and t == "userdata" then
+		-- when userdata (e.g. player) is passed directly, print its metatable:
+		return "userdata metatable: " .. dump(getmetatable(o))
+	end
+	if t ~= "table" then
+		return basic_dump(o)
+	end
+	-- Contains table -> true/nil of currently nested tables
+	nested = nested or {}
+	if nested[o] then
+		return "<circular reference>"
+	end
+	nested[o] = true
+	indent = indent or "\t"
+	level = level or 1
+	local t = {}
+	local dumped_indexes = {}
+	for i, v in ipairs(o) do
+		t[#t + 1] = dump(v, indent, nested, level + 1)
+		dumped_indexes[i] = true
+	end
+	for k, v in pairs(o) do
+		if not dumped_indexes[k] then
+			if type(k) ~= "string" or not is_valid_identifier(k) then
+				k = "["..dump(k, indent, nested, level + 1).."]"
+			end
+			v = dump(v, indent, nested, level + 1)
+			t[#t + 1] = k.." = "..v
+		end
+	end
+	nested[o] = nil
+	if indent ~= "" then
+		local indent_str = "\n"..string.rep(indent, level)
+		local end_indent_str = "\n"..string.rep(indent, level - 1)
+		return string.format("{%s%s%s}",
+				indent_str,
+				table.concat(t, ","..indent_str),
+				end_indent_str)
+	end
+	return "{"..table.concat(t, ", ").."}"
+end
+
+--------------------------------------------------------------------------------
+function string.split(str, delim, include_empty, max_splits, sep_is_pattern)
+	delim = delim or ","
+	max_splits = max_splits or -2
+	local items = {}
+	local pos, len = 1, #str
+	local plain = not sep_is_pattern
+	max_splits = max_splits + 1
+	repeat
+		local np, npe = string_find(str, delim, pos, plain)
+		np, npe = (np or (len+1)), (npe or (len+1))
+		if (not np) or (max_splits == 1) then
+			np = len + 1
+			npe = np
+		end
+		local s = string_sub(str, pos, np - 1)
+		if include_empty or (s ~= "") then
+			max_splits = max_splits - 1
+			items[#items + 1] = s
+		end
+		pos = npe + 1
+	until (max_splits == 0) or (pos > (len + 1))
+	return items
+end