code: function(parser) {
      return highland.map(function(item) {
        if (_.isFunction(parser)) {
          return parser(item);
        }
        if (_.isObject(parser) && (parser.parse != null)) {
          return parser.parse(item);
        }
        return item;
      });
    }
docs: Builder; returns a function which can be used to map a stream with a
  given parser.
  
  @param {Function|Object} parser can be either a function or an object, in
  which case the parser.parse() will be used.
  
  @return {Function} curried map().
  
  @private