Saxon » SaxonC

SaxonC currently does not properly represent empty sequences via the API. What we need is an XdmEmptySequence class similar to its Java counterpart. Moreover, In SaxonJ (Java) an empty XdmValue is also an empty sequence which can be passed as a parameter to an expression of stylesheet, but this fails in SaxonC.

For example:

    xp = saxonproc.new_xpath_processor()
    xp.declare_namespace("fn", "http://www.w3.org/2005/xpath-functions")
    xp.declare_variable('p')
    xdm_value = PyXdmValue()
    xp.set_parameter('p', xdm_value)
    assert xp.effective_boolean_value("fn:empty($p)")

Crashes out with the following exception:

java.lang.IllegalArgumentException: Invalid handle
    at com.oracle.svm.core.handles.ObjectHandlesImpl.doGet(ObjectHandlesImpl.java:232)
    at com.oracle.svm.core.handles.ObjectHandlesImpl.get(ObjectHandlesImpl.java:220)
    at net.sf.saxon.option.cpp.ProcessorDataAccumulator.addProcessorDataPair(ProcessorDataAccumulator.java:93)

This is probably because the empty PyXdmValue() object is not internally getting converted to an empty sequence.