Error system on HXT

Question

Is there a way to create an error log with HXT ? Or do i need to create mine ? I saw that there is an error system for HXT but there is not so much information available... My idea was to collect all the error, branches which he didnt parse, and put it on a log file with the corresponding line (branches which he didn't parse) .

Parsing tree

content of:

---XTag "owl:Class"
   |   "rdf:about"="http://www.xfront.com/owl/ontologies/camera/#Viewer"
   |
   +---XTag "owl:equivalentClass"
      |
      +---XTag "owl:Class"
          |
          +---XTag "owl:oneOf"
              |   "rdf:parseType"="Collection"
              |
              +---XTag "rdf:Description"
              |   |   "rdf:about"="http://www.xfront.com/owl/ontologies/camera/#ThroughTheLens"
              |
              +---XTag "rdf:Description"
                  |   "rdf:about"="http://www.xfront.com/owl/ontologies/camera/#WindowOnTopOfCamera"

If the rdf:about isn't there on the owl:Class, i must throw an error for example.

Answer 1

It appears that you can set an error message handler, which can then be used to write to which ever log you wish.

See http://hackage.haskell.org/package/hxt-9.3.1.4/docs/Text-XML-HXT-Arrow-XmlState-ErrorHandling.html

In particular,

• getErrorMessages :: IOStateArrow s b XmlTree
• addToErrorMsgList :: IOStateArrow s XmlTree XmlTree