[stringtemplate-interest] inconsistency with length function

[John Snyders]

Woops, should be
} else if (attribute instanceof Collection) {
  i = ((Collection)attribute).size();
}

  -----Original Message-----
  From: John Snyders [mailto:jjsnyders at rcn.com]
  Sent: Wednesday, January 17, 2007 12:52 AM
  To: stringtemplate-interest at antlr.org
  Subject: inconsistency with length function


  The length function knows how to get the length of List, Map, arrays, and
Iterator. However convertAnythingIteratableToIterator and
convertAnythingToIterator are more general and get iterators for Collection
rather than List.

  I think that the length method in ASTExpr.java should be changed as
follows:

  From:

  } else if (attribute instanceof List) {
    i = ((List)attribute).size();
  }

  To:

  } else if (attribute instanceof Collection) {
    i = ((List)attribute).size();
  }

  In addition I don't think Iterator should be handled like it is. Getting
the length of an iterator will use it up so that it can't be used again.
  Some rethinking of how iterators are dealt with is needed. Until then it
would be good practice to never pass an iterator in as a ST attribute.

  The issue is the same as what lead to Iterable being added to Java 5 in
order to support the new foreach syntax. Because an iterator is single use
only there needed to be a way to get the iterator again and again.

  Thanks,
  -John
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.antlr.org:8080/pipermail/stringtemplate-interest/attachments/20070117/88c78063/attachment.html