code: function Tokenizer(s, f, l) {
      this.cursor = 0;
      this.source = String(s);
      this.tokens = [];
      this.tokenIndex = 0;
      this.lookahead = 0;
      this.scanNewlines = false;
      this.unexpectedEOF = false;
      this.filename = f || "";
      this.lineno = l || 1;
  }
docs: /*
  Tokenizer :: (source, filename, line number) -> Tokenizer