JS: Types for chr(), .indexOf(), .slice()

applications/system/js_app/types/global.d.ts

@@ -56,6 +56,15 @@ declare const __filepath: string;
  */
 declare function load(path: string): any;
 
+/**
+ * @brief Return 1-byte string whose ASCII code is the integer `n`
+ * 
+ * If `n` is not numeric or outside of `0-255` range, `null` is returned
+ * 
+ * @param n The ASCII code to convert to string
+ */
+declare function chr(n: number): string | null;
+
 /**
  * @brief mJS Foreign Pointer type
  * 
@@ -189,6 +198,18 @@ declare class String {
      * See `charCodeAt`
      */
     at(index: number): number;
+    /**
+     * @brief Return index of first occurence of substr within the string or `-1` if not found
+     * @param substr The string to search for
+     * @param fromIndex The index to start searching from
+     */
+    indexOf(substr: string, fromIndex?: number): number;
+    /**
+     * @brief Return a substring between two indices
+     * @param start The index to start substring at
+     * @param end The index to end substring at
+     */
+    slice(start: number, end?: number): string;
 }
 
 declare class Boolean { }