Lua API: Add __dir metamethod to unit variables and unit statuses

src/scripting/lua_unit.cpp

@@ -832,6 +832,32 @@ static int impl_unit_status_set(lua_State *L)
 	return 0;
 }
 
+/**
+ * List statuses on a unit (__dir metamethod)
+ * This returns all known statuses (regardless of state) plus any currently set to true.
+ */
+static int impl_unit_status_dir(lua_State *L)
+{
+	if(!lua_istable(L, 1)) {
+		return luaW_type_error(L, 1, "unit status");
+	}
+	lua_rawgeti(L, 1, 1);
+	unit* u = luaW_tounit(L, -1);
+	if(!u) {
+		return luaL_argerror(L, 1, "unknown unit");
+	}
+	std::vector<std::string> states;
+	states.reserve(unit::NUMBER_OF_STATES);
+	for(unit::state_t s = unit::STATE_SLOWED; s < unit::NUMBER_OF_STATES; s = unit::state_t(s + 1)) {
+		states.push_back(unit::get_known_boolean_state_name(s));
+	}
+	for(auto s : u->get_states()) {
+		states.push_back(s);
+	}
+	lua_push(L, states);
+	return 1;
+}
+
 /**
  * Gets the variable of a unit (__index metamethod).
  * - Arg 1: table containing the userdata containing the unit id.
@@ -886,6 +912,32 @@ static int impl_unit_variables_set(lua_State *L)
 	return 0;
 }
 
+/**
+ * List variables on a unit (__dir metamethod)
+ */
+static int impl_unit_variables_dir(lua_State *L)
+{
+	if(!lua_istable(L, 1)) {
+		return luaW_type_error(L, 1, "unit variables");
+	}
+	lua_rawgeti(L, 1, 1);
+	unit* u = luaW_tounit(L, -1);
+	if(!u) {
+		return luaL_argerror(L, 2, "unknown unit");
+	}
+	config& vars = u->variables();
+	std::vector<std::string> variables;
+	variables.reserve(vars.attribute_count() + vars.all_children_count());
+	for(const auto& attr : vars.attribute_range()) {
+		variables.push_back(attr.first);
+	}
+	for(auto attr : vars.all_children_range()) {
+		variables.push_back(attr.key);
+	}
+	lua_push(L, variables);
+	return 1;
+}
+
 namespace lua_units {
 	std::string register_metatables(lua_State* L)
 	{
@@ -918,6 +970,8 @@ namespace lua_units {
 		lua_setfield(L, -2, "__index");
 		lua_pushcfunction(L, impl_unit_status_set);
 		lua_setfield(L, -2, "__newindex");
+		lua_pushcfunction(L, impl_unit_status_dir);
+		lua_setfield(L, -2, "__dir");
 		lua_pushstring(L, "unit status");
 		lua_setfield(L, -2, "__metatable");
 
@@ -929,6 +983,8 @@ namespace lua_units {
 		lua_setfield(L, -2, "__index");
 		lua_pushcfunction(L, impl_unit_variables_set);
 		lua_setfield(L, -2, "__newindex");
+		lua_pushcfunction(L, impl_unit_variables_dir);
+		lua_setfield(L, -2, "__dir");
 		lua_pushstring(L, "unit variables");
 		lua_setfield(L, -2, "__metatable");
 

src/units/unit.cpp

@@ -1357,6 +1357,16 @@ unit::state_t unit::get_known_boolean_state_id(const std::string& state)
 	return STATE_UNKNOWN;
 }
 
+std::string unit::get_known_boolean_state_name(state_t state)
+{
+	for(const auto& p : known_boolean_state_names_) {
+		if(p.second == state) {
+			return p.first;
+		}
+	}
+	return "";
+}
+
 std::map<std::string, unit::state_t> unit::known_boolean_state_names_ {
 	{"slowed",       STATE_SLOWED},
 	{"poisoned",     STATE_POISONED},

src/units/unit.hpp

@@ -889,6 +889,12 @@ public:
 	 */
 	static state_t get_known_boolean_state_id(const std::string& state);
 
+	/**
+	 * Convert a built-in status effect ID to a string status effect ID
+	 * @returns the string representing the status, or an empty string for STATE_UNKNOWN
+	 */
+	static std::string get_known_boolean_state_name(state_t state);
+
 	/**
 	 * Check if the unit has been poisoned
 	 * @returns true if it's poisoned