net.sf.saxon.expr
Class BooleanExpression
java.lang.Object
net.sf.saxon.expr.ComputedExpression
net.sf.saxon.expr.BinaryExpression
net.sf.saxon.expr.BooleanExpression
- All Implemented Interfaces:
- Container, Expression, InstructionInfoProvider, java.io.Serializable, javax.xml.transform.SourceLocator
- public class BooleanExpression
- extends BinaryExpression
Boolean expression: two truth values combined using AND or OR.
- See Also:
- Serialized Form
Methods inherited from class net.sf.saxon.expr.BinaryExpression |
computeSpecialProperties, display, displayOperator, equals, getOperands, getOperator, hashCode, isCommutative, isInverse, iterateSubExpressions, optimize, promote, simplify, typeCheck |
Methods inherited from class net.sf.saxon.expr.ComputedExpression |
adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, dynamicError, evaluateAsString, getCardinality, getColumnNumber, getConstructType, getDependencies, getExecutable, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, iterate, markTailFunctionCalls, process, resetStaticProperties, setLocationId, setParentExpression, typeError, typeError |
Methods inherited from class java.lang.Object |
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait |
BooleanExpression
public BooleanExpression(Expression p1,
int operator,
Expression p2)
computeCardinality
public int computeCardinality()
- Determine the static cardinality. Returns [1..1]
- Overrides:
computeCardinality
in class BinaryExpression
evaluateItem
public Item evaluateItem(XPathContext context)
throws XPathException
- Evaluate the expression
- 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 as a boolean.
- 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
getItemType
public ItemType getItemType()
- Determine the data type of the expression
- Returns:
- Type.BOOLEAN
listAndComponents
public static void listAndComponents(Expression exp,
java.util.List list)
- Construct a list containing the "anded" subexpressions of an expression:
if the expression is (A and B and C), this returns (A, B, C).
TODO: could do more complete analysis to convert the expression to conjunctive normal form
- Parameters:
exp
- the expression to be decomposedlist
- the list to which the subexpressions are to be added.