net.sf.saxon.functions
Class Evaluate
java.lang.Object
|
+--net.sf.saxon.expr.ComputedExpression
|
+--net.sf.saxon.expr.FunctionCall
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+--net.sf.saxon.functions.SystemFunction
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+--net.sf.saxon.functions.Evaluate
- All Implemented Interfaces:
- Expression, java.io.Serializable, XSLTFunction
- public class Evaluate
- extends SystemFunction
- implements XSLTFunction
This class implements the saxon:evaluate(), saxon:expression(), and saxon:eval() extension functions,
which are specially-recognized by the system because they needs access
to parts of the static context
- See Also:
- Serialized Form
Nested Class Summary |
protected static class |
Evaluate.PreparedExpression
Inner class PreparedExpression represents a compiled XPath expression together
with the standard variables $p1 .. |
Methods inherited from class net.sf.saxon.expr.ComputedExpression |
computeDependencies, computeSpecialProperties, computeStaticProperties, dynamicError, effectiveBooleanValue, evaluateAsString, getCardinality, getDependencies, getLineNumber, getSpecialProperties, markTailFunctionCalls, setLineNumber, typeError |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
EVALUATE
public static final int EVALUATE
- See Also:
- Constant Field Values
EXPRESSION
public static final int EXPRESSION
- See Also:
- Constant Field Values
EVAL
public static final int EVAL
- See Also:
- Constant Field Values
Evaluate
public Evaluate()
getRequiredType
protected SequenceType getRequiredType(int arg)
- Get the required type of the nth argument
- Overrides:
getRequiredType
in class SystemFunction
checkArguments
public void checkArguments(StaticContext env)
throws XPathException
- Method supplied by each class of function to check arguments during parsing, when all
the argument expressions have been read
- Overrides:
checkArguments
in class SystemFunction
XPathException
preEvaluate
public Expression preEvaluate(StaticContext env)
- preEvaluate: this method suppresses compile-time evaluation by doing nothing
(because the value of the expression depends on the runtime context)
- Overrides:
preEvaluate
in class FunctionCall
evaluateItem
public Item evaluateItem(XPathContext c)
throws XPathException
- Evaluate in a general context
- Specified by:
evaluateItem
in interface Expression
- Overrides:
evaluateItem
in class ComputedExpression
- Parameters:
c
- The context in which the expression is to be evaluated
- Returns:
- the node or atomic value that results from evaluating the
expression; or null to indicate that the result is an empty
sequence
- Throws:
XPathException
- if any dynamic error occurs evaluating the
expression
iterate
public SequenceIterator iterate(XPathContext c)
throws XPathException
- Iterate over the results of the function
- Specified by:
iterate
in interface Expression
- Overrides:
iterate
in class ComputedExpression
- Parameters:
c
- supplies the context for evaluation
- Returns:
- a SequenceIterator that can be used to iterate over the result
of the expression
- Throws:
XPathException
- if any dynamic error occurs evaluating the
expression
getIntrinsicDependencies
public int getIntrinsicDependencies()
- Determine the dependencies
- Overrides:
getIntrinsicDependencies
in class ComputedExpression
- Returns:
- a set of bit-significant flags identifying the "intrinsic"
dependencies. The flags are documented in class net.sf.saxon.value.StaticProperty