XOM API for Processing XML with Java

[Elliotte Rusty Harold <elharo AT metalab.unc.edu>]

At 10:48 PM -0500 3/9/04, John Cowan wrote:

> Fair enough; Element doesn't, after all.  You could use reflection to
> look for the constructor with a single String argument, though, and
> blow chunks if there isn't one.

Or the double string, if you need to put something in a namespace. 
But what if the subclass has swapped the arguments? What if it's 
doing something unusual and only has constructors with three 
arguments? Bleah.

If I become convinced this is important to fix, I think I'm going to 
have to add an additional protected method whose purpose is simply to 
build an empty element of the relevant type.  In this case, perhaps 
copy() could be made final. The main reason copy isn't final now is 
precisely so subclasses can make it return an instance of the 
subclass rather than an instance of the superclass. However, this 
would be inconsistent with the definition of final in the other Node 
classes so I may not do this.

I don't know. I'm really tempted to wait until someone files an 
actual bug on this one before fixing it. Especially since I'm seeing 
some evidence that the non-recursive algorithms are a big performance 
hit. (Not everything that needs to be O(1) to make your algorithm 
perform is actually O(1) in XOM. :-( ) I may be able to fix that but 
only at the cost of setting up and using a temporary stack in every 
invocation to getValue(). Even if it's O(1) the fixed costs may kill 
me.
--

  Elliotte Rusty Harold
  elharo AT metalab.unc.edu
  Effective XML (Addison-Wesley, 2003)
  http://www.cafeconleche.org/books/effectivexml
  http://www.amazon.com/exec/obidos/ISBN%3D0321150406/ref%3Dnosim/cafeaulaitA