Add _error and _map_of

Also fix to _keys for empty maps

Author: twisterghost

src/gdash.yyp

@@ -1 +1,22 @@
-test_suite_pass();
+/// @description _map_of
+test_start("_map_of", "returns a map of the given parameters, paired as key/value");
+var res = _map_of(
+    "hello", 1,
+    "world", 2,
+    "test", 3
+);
+
+assert_is_true(ds_exists(res, ds_type_map));
+assert_equal(res[? "hello"], 1);
+assert_equal(res[? "world"], 2);
+assert_equal(res[? "test"], 3);
+
+ds_map_destroy(res);
+
+// Odd argument count - fails with empty map
+res = _map_of(1);
+assert_is_true(ds_exists(res, ds_type_map));
+assert_equal(_length(_keys(res)), 0);
+ds_map_destroy(res);
+
+test_end();

src/objects/obj_gdash_test_3/Other_12.gml

@@ -0,0 +1 @@
+test_suite_pass();

src/objects/obj_gdash_test_3/Other_13.gml

@@ -0,0 +1,20 @@
+/// @func _error(message [, fatal])
+/// @desc When running with the debugger, displays an error window. Otherwise, logs an error using _log.
+/// @param {String} message The message to error with
+/// @param {Boolean} fatal [Optional] If true, will force a show_error() call with `abort` set to true
+/// @note Only mark an error as `fatal` if you are okay with it ending your game
+/*
+@example
+_error("This is an error that will let the game continue");
+_error("This is an error that will let the game continue", false);
+_error("This is an error that will kill the game", true);
+*/
+
+var message = argument[0];
+var fatal = argument_count > 1 ? argument[1] : false;
+
+if (fatal || debug_mode) {
+    show_error(message, fatal);
+} else {
+    _log("ERROR: " + message);
+}

src/objects/obj_gdash_test_3/obj_gdash_test_3.yy

@@ -16,7 +16,7 @@ _keys(map);
 var map = argument0;
 var nextKey = ds_map_find_first(map);
 var nextInd = 0;
-var keys;
+var keys = [];
 
 while (!is_undefined(nextKey)) {
     keys[nextInd++] = nextKey;

src/scripts/_error/_error.gml

@@ -0,0 +1,44 @@
+/// @func _map_of(values...)
+/// @desc Returns a DS_Map containing the provided values. Arguments are split into key/value pairs in the order they are provided.
+/// @note This script must take an even number of arguments. Keys can only be integers or strings.
+/// @param {*} values... As many starting values for the map as desired
+/// @returns {DS_Map} A new DS_Map containing the provided key/value pairs
+/*
+@example
+
+var map = _map_of(
+    "health", 100,
+    "mana", 20,
+    "level", 1
+);
+
+map[? "health"] // = 100
+map[? "mana"] // = 20
+map[? "level"] // = 1
+
+*/
+
+if (argument_count % 2 != 0) {
+    _error("_map_of must take an even number of arguments. This call will return an empty map.", false);
+    return ds_map_create();
+}
+
+// Ensure keys are integers or strings
+for (var i = 0; i < argument_count; i += 2) {
+    var key = argument[i];
+    var type = typeof(key);
+    if (type != "number" && type != "string") {
+        _error("_map_of must take keys that are strings or integers. This call will return an empty map.\nOffending key: " + string(key), false);
+        return ds_map_create();
+    }
+}
+
+var map = ds_map_create();
+
+for (var i = 0; i < argument_count; i++) {
+    var key = argument[i++];
+    var value = argument[i];
+    map[? key] = value;
+}
+
+return map;