public final class InstanceOfExpression extends UnaryExpression
Modifier and Type | Field and Description |
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(package private) int |
targetCardinality |
(package private) ItemType |
targetType |
operand
locationId, staticProperties
EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD
Constructor and Description |
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InstanceOfExpression(Expression source,
SequenceType target) |
Modifier and Type | Method and Description |
---|---|
int |
computeCardinality()
Determine the cardinality
|
void |
display(int level,
java.io.PrintStream out,
Configuration config)
Diagnostic print of expression structure
|
protected java.lang.String |
displayOperator(Configuration config)
Give a string representation of the operator for use in diagnostics
|
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
|
ItemType |
getItemType(TypeHierarchy th)
Determine the data type of the result of the InstanceOf expression
|
Expression |
optimize(Optimizer opt,
StaticContext env,
ItemType contextItemType)
Perform optimisation of an expression and its subexpressions.
|
Expression |
typeCheck(StaticContext env,
ItemType contextItemType)
Type-check the expression
|
computeSpecialProperties, getBaseExpression, hashCode, iterateSubExpressions, promote, replaceSubExpression, simplify
adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, evaluateAsString, getCardinality, getColumnNumber, getConstructType, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, iterate, markTailFunctionCalls, process, resetStaticProperties, setLocationId, setParentExpression, setParentExpression, suppressValidation, typeError
ItemType targetType
int targetCardinality
public InstanceOfExpression(Expression source, SequenceType target)
public Expression typeCheck(StaticContext env, ItemType contextItemType) throws XPathException
typeCheck
in interface Expression
typeCheck
in class UnaryExpression
env
- the static context of the expressioncontextItemType
- 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
StaticError
- if an error is discovered during this phase
(typically a type error)XPathException
public Expression optimize(Optimizer opt, StaticContext env, 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 interface Expression
optimize
in class UnaryExpression
opt
- the optimizer in use. This provides access to supporting functions; it also allows
different optimization strategies to be used in different circumstances.env
- the static context of the expressioncontextItemType
- 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
StaticError
- if an error is discovered during this phase
(typically a type error)XPathException
public boolean equals(java.lang.Object other)
equals
in class UnaryExpression
public int computeCardinality()
computeCardinality
in class UnaryExpression
public ItemType getItemType(TypeHierarchy th)
getItemType
in interface Expression
getItemType
in class UnaryExpression
th
- public Item evaluateItem(XPathContext context) throws XPathException
evaluateItem
in interface Expression
evaluateItem
in class ComputedExpression
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 interface Expression
effectiveBooleanValue
in class ComputedExpression
context
- The context in which the expression is to be evaluatedXPathException
- if any dynamic error occurs evaluating the
expressionprotected java.lang.String displayOperator(Configuration config)
displayOperator
in class UnaryExpression
config
- public void display(int level, java.io.PrintStream out, Configuration config)
display
in interface Expression
display
in class UnaryExpression
level
- indentation level for this expressionout
- Output destination