public List<ValueSource> parseValueSourceList() throws SyntaxError {
  List<ValueSource> sources=new ArrayList<>(3);
  while (hasMoreArguments()) {
    sources.add(parseValueSource(true));
  }
  return sources;
}

public List < ValueSource > parseValueSourceList ( ) throws SyntaxError { List < ValueSource > sources = new ArrayList < > ( 3 ) ; while ( hasMoreArguments ( ) ) { sources . add ( parseValueSource ( true ) ) ; } return sources ; }
parse a list of valuesource . must be the final set of arguments to a valuesource .
