Permit PolyNull to take an argument

[GoogleCodeExporter]

It would be nice for PolyNull to take an optional argument, so that
multiple different instantiations of PolyNull can be used in a single
method.  The need for this is very rare, but here is a concrete example:


  /** Returns an array of Strings, where the strings are the result of
   * invoking x.getClass().toString() for each element x in the
   * array. If an element of the array is null, its slot in the returned
   * array is null.
   */
  public static
  @PolyNull("elt") String @PolyNull("container") []
  typeArray(@PolyNull("elt") Object @PolyNull("container") [] seq) {
    if (seq == null) { return null; }
    @PolyNull("elt") String[] retval = new @PolyNull("elt") String[seq.length];
    for (int i = 0 ; i < seq.length ; i++) {
      if (seq[i] == null) {
        retval[i] = null;
      } else {
        retval[i] = seq[i].getClass().toString();
      }
    }
    return retval;
  }

Original issue reported on code.google.com by michael.ernst@gmail.com on 12 Jan 2010 at 5:21

• Merged into: PolymorphicQualifier for qualifiers with elements (values, fields) #58