docs: function compile(src) {
     var cached;
  
     if (typeof src !== "string") {
        throw new TypeError("src must be a string, instead saw '" + typeof src + "'");
     }
  
     if (!compile.cache) {
        return parser.parse(src);
     }
  
     cached = compile.cache[src];
  
     if (!cached) {
        cached = compile.cache[src] = parser.parse(src);
     }
  
     return cached;
  }