public final class InstanceOfExpression extends UnaryExpression
operand
EVALUATE_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties
Constructor and Description |
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InstanceOfExpression(Expression source,
SequenceType target)
Construct an "instance of" expression in the form "source instance of target"
|
Modifier and Type | Method and Description |
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int |
computeCardinality()
Determine the cardinality
|
Expression |
copy()
Copy an expression.
|
boolean |
effectiveBooleanValue(XPathContext context)
Evaluate the expression as a boolean
|
boolean |
equals(java.lang.Object other)
Is this expression the same as another expression?
|
Item |
evaluateItem(XPathContext context)
Evaluate the expression
|
void |
explain(ExpressionPresenter destination)
Diagnostic print of expression structure.
|
ItemType |
getItemType(TypeHierarchy th)
Determine the data type of the result of the InstanceOf expression
|
int |
getRequiredCardinality()
Get the cardinality that we are testing for membership of
|
ItemType |
getRequiredItemType()
Get the item type that we are testing for membership of
|
Expression |
optimize(ExpressionVisitor visitor,
ItemType contextItemType)
Perform optimisation of an expression and its subexpressions.
|
Expression |
typeCheck(ExpressionVisitor visitor,
ItemType contextItemType)
Type-check the expression
|
computeSpecialProperties, displayExpressionName, displayOperator, getBaseExpression, hashCode, iterateSubExpressions, promote, replaceSubExpression, simplify, toString
addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, display, doPromotion, dynamicError, evaluateAsString, evaluatePendingUpdates, explain, findParentOf, getCardinality, getColumnNumber, getColumnNumber, getConstructType, getContainer, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, isUpdatingExpression, iterate, iterateEvents, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, typeError
public InstanceOfExpression(Expression source, SequenceType target)
source
- the expression whose type is to be testedtarget
- the type against which it is testedpublic ItemType getRequiredItemType()
public int getRequiredCardinality()
public Expression typeCheck(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException
typeCheck
in class UnaryExpression
visitor
- an expression visitorcontextItemType
- the static type of "." at the point where this expression is invoked.
The parameter is set to null if it is known statically that the context item will be undefined.
If the type of the context item is not known statically, the argument is set to
Type.ITEM_TYPE
XPathException
- if an error is discovered during this phase
(typically a type error)public Expression optimize(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException
This method is called after all references to functions and variables have been resolved to the declaration of the function or variable, and after all type checking has been done.
optimize
in class UnaryExpression
visitor
- an expression visitorcontextItemType
- the static type of "." at the point where this expression is invoked.
The parameter is set to null if it is known statically that the context item will be undefined.
If the type of the context item is not known statically, the argument is set to
Type.ITEM_TYPE
XPathException
- if an error is discovered during this phase
(typically a type error)public boolean equals(java.lang.Object other)
equals
in class UnaryExpression
public int computeCardinality()
computeCardinality
in class UnaryExpression
StaticProperty.ALLOWS_ZERO_OR_ONE
,
StaticProperty.EXACTLY_ONE
, StaticProperty.ALLOWS_ONE_OR_MORE
,
StaticProperty.ALLOWS_ZERO_OR_MORE
public Expression copy()
copy
in class Expression
public ItemType getItemType(TypeHierarchy th)
getItemType
in class UnaryExpression
th
- the type hierarchy cachepublic Item evaluateItem(XPathContext context) throws XPathException
evaluateItem
in interface EvaluableItem
evaluateItem
in class Expression
context
- The context in which the expression is to be evaluatedXPathException
- if any dynamic error occurs evaluating the
expressionpublic boolean effectiveBooleanValue(XPathContext context) throws XPathException
effectiveBooleanValue
in class Expression
context
- The context in which the expression is to be evaluatedXPathException
- if any dynamic error occurs evaluating the
expressionpublic void explain(ExpressionPresenter destination)
explain
in class UnaryExpression
destination
- the expression presenter used to display the structure