code: function primitive (data) {
      var type;
  
      switch (data) {
        case null:
        case undefined:
        case false:
        case true:
          return true;
      }
  
      type = typeof data;
      return type === 'string' || type === 'number' || (haveSymbols && type === 'symbol');
    }
docs: Public function `primitive`.
  
  Returns true if `data` is a primitive type, false otherwise.