Key Instance type checking

worldeditadditions/utils/parse/key_instance.lua

@@ -1,16 +1,42 @@
---- A container for transmitting axis, sign pairs within parsing functions.
+--- A container for transmitting (axis table, sign) or (dir, sign) pairs
+-- and other data within parsing functions.
 -- @class
 local key_instance = {}
 key_instance.__index = key_instance
 key_instance.__name = "Key Instance"
 
+-- Allowed values for "type" field
+local types = {
+	err = true, rev = true,
+	axis = true, dir = true,
+	replace = {
+		error = "err",
+		axes = "axis",
+	},
+}
+
+-- Simple function for putting stuff in quotes
+local function enquote(take)
+	if type(take) == "string" then
+		return '"'..take..'"'
+	else return tostring(take) end
+end
+
 --- Creates a new Key Instance.
--- @param: type: String: Key type (axis, direction, mirroring or error).
+-- This is a table with a "type" string, an entry string or table
+-- and an optional signed integer (or code number in the case of errors)
+-- @param: type: String: Key type (axis, dir(ection), rev (mirroring) or error).
 -- @param: entry: String: The main content of the key.
 -- @param: sign: Int: The signed multiplier of the key (if any).
 -- @return: Key Instance: The new Key Instance.
 function key_instance.new(type,entry,sign)
-	if type == "error" then type = "err" end
+	if types.replace[type] then
+		type = types.replace[type]
+	elseif not types[type] then
+		return key_instance.new("err",
+		"Key Instance internal error: Invalid type "..enquote(type)..".",
+		500)
+	end
 	local tbl = {type = type, entry = entry}
 	if sign and sign ~= 0 then
 		if type == "err" then tbl.code = sign
@@ -46,11 +72,6 @@ function key_instance.is_error(a)
 end
 
 function key_instance.__tostring(a)
-	local function enquote(take)
-		if type(take) == "string" then
-			return '"'..take..'"'
-		else return tostring(take) end
-	end
 	local ret = "{type = "..enquote(a.type)..", entry = "
 	if type(a.entry) == "table" and #a.entry <= 3 then
 		ret = ret.."{"