net.sf.saxon.functions

Class Trace

public class Trace extends SystemFunction

This class supports the XPath 2.0 function trace(). The value is traced to the System.err stream, unless a TraceListener is in use, in which case the information is sent to the TraceListener

Nested Class Summary
class	Trace.TracingIterator Tracing Iterator class

Field Summary
NamespaceResolver	resolver

Method Summary
int	computeCardinality() Get the static cardinality
int	computeSpecialProperties() Get the static properties of this expression (other than its type).
Item	evaluateItem(XPathContext context) Evaluate the function
SequenceIterator	iterate(XPathContext context) Iterate over the results of the function
Expression	preEvaluate(StaticContext env) preEvaluate: this method suppresses compile-time evaluation by doing nothing
Expression	simplify(StaticContext env) Simplify the function call.

Method Detail

computeCardinality

public int computeCardinality()

Get the static cardinality

Get the static properties of this expression (other than its type). The result is bit-significant. These properties are used for optimizations. In general, if property bit is set, it is true, but if it is unset, the value is unknown.

evaluateItem

public Item evaluateItem(XPathContext context)

Evaluate the function

iterate

public SequenceIterator iterate(XPathContext context)

Iterate over the results of the function

preEvaluate

public Expression preEvaluate(StaticContext env)

preEvaluate: this method suppresses compile-time evaluation by doing nothing

simplify

public Expression simplify(StaticContext env)

Simplify the function call. This implementation saves the static namespace context, in case it is needed by the TraceListener.