question about Parser Liaison and Documents

[Paul Levin]

I realize that the Document implementation class used, and the ParserLiaison class used, are tightly coupled.

I notice, in the latest Xalan distribution, that there are 2 significant Liaison/Document packages --
 
 

ParsserLiaison Class	Document Impl Class
org.apache.xalan.xpath.xdom.XercesLiaison	org.apache.xerces.dom.DocumentImpl
org.apache.xalan.xpath.dtm.DTMLiaison	org.apache.xalan.xpath.dtm.DTMProxy

I am trying to understand some pros and cons of these 2 choices.

• It seems that the DTM classes are supposed to be faster than the Xerces classes.
• The Xerces DocumentImpl class has a constructor (so a document can be made without having to parse a file); where as the DTMProxy class has no constructor.

Would people please comment on these findings, and correct me where I am wrong,

I need to be able to instantiate a Document without parsing, so it looks like my only choice is the Xerces classes, even though they are slower than the DTM.  Again, please comment.

    Thanks