Optimize translator

- Use `slice` less
- Skip iterations with `indexOf`

public/src/modules/translator.js

@@ -111,10 +111,10 @@
 				var level = 0;
 
 				while (i + 2 <= len) {
-					if (text.slice(i, i + 2) === '[[') {
+					if (text[i] === '[' && text[i + 1] === '[') {
 						level += 1;
 						i += 1;
-					} else if (text.slice(i, i + 2) === ']]') {
+					} else if (text[i] === ']' && text[i + 1] === ']') {
 						level -= 1;
 						i += 1;
 					} else if (level === 0 && text[i] === ',' && text[i - 1] !== '\\') {
@@ -128,13 +128,13 @@
 				return arr;
 			}
 
+			// move to the first [[
+			cursor = str.indexOf('[[', cursor);
+
 			// the loooop, we'll go to where the cursor
 			// is equal to the length of the string since
 			// slice doesn't include the ending index
-			while (cursor + 2 <= len) {
-				// if the current position in the string looks
-				// like the beginning of a translation string
-				if (str.slice(cursor, cursor + 2) === '[[') {
+			while (cursor + 2 <= len && cursor !== -1) {
 				// split the string from the last break
 				// to the character before the cursor
 				// add that to the result array
@@ -150,7 +150,8 @@
 
 				// the current level of nesting of the translation strings
 				var level = 0;
-					var sliced;
+				var char0;
+				var char1;
 				// validating the current string is actually a translation
 				var textBeforeColonFound = false;
 				var colonFound = false;
@@ -158,28 +159,29 @@
 				var commaAfterNameFound = false;
 
 				while (cursor + 2 <= len) {
-						sliced = str.slice(cursor, cursor + 2);
+					char0 = str[cursor];
+					char1 = str[cursor + 1];
 					// found some text after the double bracket,
 					// so this is probably a translation string
-						if (!textBeforeColonFound && validTextRegex.test(sliced[0])) {
+					if (!textBeforeColonFound && validTextRegex.test(char0)) {
 						textBeforeColonFound = true;
 						cursor += 1;
 					// found a colon, so this is probably a translation string
-						} else if (textBeforeColonFound && !colonFound && sliced[0] === ':') {
+					} else if (textBeforeColonFound && !colonFound && char0 === ':') {
 						colonFound = true;
 						cursor += 1;
 					// found some text after the colon,
 					// so this is probably a translation string
-						} else if (colonFound && !textAfterColonFound && validTextRegex.test(sliced[0])) {
+					} else if (colonFound && !textAfterColonFound && validTextRegex.test(char0)) {
 						textAfterColonFound = true;
 						cursor += 1;
-						} else if (textAfterColonFound && !commaAfterNameFound && sliced[0] === ',') {
+					} else if (textAfterColonFound && !commaAfterNameFound && char0 === ',') {
 						commaAfterNameFound = true;
 						cursor += 1;
 					// a space or comma was found before the name
 					// this isn't a translation string, so back out
 					} else if (!(textBeforeColonFound && colonFound && textAfterColonFound && commaAfterNameFound) &&
-								invalidTextRegex.test(sliced[0])) {
+							invalidTextRegex.test(char0)) {
 						cursor += 1;
 						lastBreak -= 2;
 						// no longer in a token
@@ -191,11 +193,11 @@
 						}
 					// if we're at the beginning of another translation string,
 					// we're nested, so add to our level
-						} else if (sliced === '[[') {
+					} else if (char0 === '[' && char1 === '[') {
 						level += 1;
 						cursor += 2;
 					// if we're at the end of a translation string
-						} else if (sliced === ']]') {
+					} else if (char0 === ']' && char1 === ']') {
 						// if we're at the base level, then this is the end
 						if (level === 0) {
 							// so grab the name and args
@@ -230,9 +232,9 @@
 						cursor += 1;
 					}
 				}
-				}
-				// move to the next character
-				cursor += 1;
+
+				// skip to the next [[
+				cursor = str.indexOf('[[', cursor);
 			}
 
 			// ending string of source
@@ -304,7 +306,7 @@
 		 * Load translation file (or use a cached version), and optionally return the translation of a certain key
 		 * @param {string} namespace - The file name of the translation namespace
 		 * @param {string} [key] - The key of the specific translation to getJSON
-		 * @returns {Promise<{ [key: string]: string }>|Promise<string>}
+		 * @returns {Promise<{ [key: string]: string } | string>}
 		 */
 		Translator.prototype.getTranslation = function getTranslation(namespace, key) {
 			var translation;