net.sf.saxon.functions
Class BooleanFn
java.lang.Object
|
+--net.sf.saxon.expr.ComputedExpression
|
+--net.sf.saxon.expr.FunctionCall
|
+--net.sf.saxon.functions.SystemFunction
|
+--net.sf.saxon.functions.BooleanFn
- All Implemented Interfaces:
- Expression, java.io.Serializable
- public class BooleanFn
- extends SystemFunction
This class supports the XPath functions boolean(), not(), true(), and false()
- See Also:
- Serialized Form
Methods inherited from class net.sf.saxon.expr.ComputedExpression |
computeDependencies, computeSpecialProperties, computeStaticProperties, dynamicError, evaluateAsString, getCardinality, getDependencies, getIntrinsicDependencies, getLineNumber, getSpecialProperties, iterate, markTailFunctionCalls, setLineNumber, typeError |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
BOOLEAN
public static final int BOOLEAN
- See Also:
- Constant Field Values
NOT
public static final int NOT
- See Also:
- Constant Field Values
TRUE
public static final int TRUE
- See Also:
- Constant Field Values
FALSE
public static final int FALSE
- See Also:
- Constant Field Values
BooleanFn
public BooleanFn()
checkArguments
public void checkArguments(StaticContext env)
throws XPathException
- Static analysis: prevent sorting of the argument
- Overrides:
checkArguments
in class SystemFunction
XPathException
evaluateItem
public Item evaluateItem(XPathContext context)
throws XPathException
- Evaluate the function
- Specified by:
evaluateItem
in interface Expression
- Overrides:
evaluateItem
in class ComputedExpression
- Parameters:
context
- 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
effectiveBooleanValue
public boolean effectiveBooleanValue(XPathContext c)
throws XPathException
- Evaluate the effective boolean value
- Specified by:
effectiveBooleanValue
in interface Expression
- Overrides:
effectiveBooleanValue
in class ComputedExpression
- Parameters:
c
- The context in which the expression is to be evaluated
- Returns:
- the effective boolean value
- Throws:
XPathException
- if any dynamic error occurs evaluating the
expression