public final class CastableExpression extends UnaryExpression
Modifier and Type | Field and Description |
---|---|
(package private) boolean |
allowEmpty |
(package private) AtomicType |
targetType |
operand
locationId, staticProperties
EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD
Constructor and Description |
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CastableExpression(Expression source,
AtomicType target,
boolean allowEmpty) |
Modifier and Type | Method and Description |
---|---|
int |
computeCardinality()
Determine the static cardinality.
|
int |
computeSpecialProperties()
Determine the special properties of this expression
|
protected String |
displayOperator(NamePool pool)
Give a string representation of the operator for use in diagnostics
|
boolean |
effectiveBooleanValue(XPathContext context)
Get the effective boolean value of the expression.
|
boolean |
equals(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 Castable expression
|
Expression |
optimize(Optimizer opt,
StaticContext env,
ItemType contextItemType)
Type-check the expression
|
Expression |
simplify(StaticContext env)
Simplify the expression
|
Expression |
typeCheck(StaticContext env,
ItemType contextItemType)
Type-check the expression
|
display, getBaseExpression, hashCode, iterateSubExpressions, promote
adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, 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, suppressValidation, typeError, typeError
AtomicType targetType
boolean allowEmpty
public CastableExpression(Expression source, AtomicType target, boolean allowEmpty)
public Expression simplify(StaticContext env) throws XPathException
simplify
in interface Expression
simplify
in class UnaryExpression
XPathException
- if an error is discovered during expression
rewritingpublic 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
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(Object other)
equals
in class UnaryExpression
public ItemType getItemType(TypeHierarchy th)
getItemType
in interface Expression
getItemType
in class UnaryExpression
th
- public int computeCardinality()
UnaryExpression
computeCardinality
in class UnaryExpression
public int computeSpecialProperties()
computeSpecialProperties
in class UnaryExpression
StaticProperty.NON_CREATIVE
.public Item evaluateItem(XPathContext context)
evaluateItem
in interface Expression
evaluateItem
in class ComputedExpression
context
- The context in which the expression is to be evaluatedpublic boolean effectiveBooleanValue(XPathContext context)
ComputedExpression
effectiveBooleanValue
in interface Expression
effectiveBooleanValue
in class ComputedExpression
context
- The context in which the expression is to be evaluatedprotected String displayOperator(NamePool pool)
displayOperator
in class UnaryExpression