public final class CastableExpression extends UnaryExpression
Modifier and Type | Field and Description |
---|---|
(package private) boolean |
allowEmpty |
(package private) AtomicType |
targetType |
operand
EVALUATE_METHOD, EVENT_FEED_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, PUSH_SELECTION, staticProperties, WATCH_METHOD
Constructor and Description |
---|
CastableExpression(Expression source,
AtomicType target,
boolean allowEmpty)
Create a "castable" expression of the form "source castable as target"
|
Modifier and Type | Method and Description |
---|---|
boolean |
allowsEmpty()
Determine whether the empty sequence is allowed
|
int |
computeCardinality()
Determine the static cardinality.
|
int |
computeSpecialProperties()
Determine the special properties of this expression
|
Expression |
copy()
Copy an expression.
|
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
|
void |
explain(ExpressionPresenter out)
Diagnostic print of expression structure.
|
ItemType |
getItemType(TypeHierarchy th)
Determine the data type of the result of the Castable expression
|
AtomicType |
getTargetType()
Get the target type
|
int |
hashCode()
get HashCode for comparing two expressions.
|
static boolean |
isCastable(AtomicValue value,
AtomicType targetType,
XPathContext context)
Determine whether a value is castable to a given type
|
Expression |
optimize(ExpressionVisitor visitor,
ItemType contextItemType)
Optimize the expression
|
Expression |
simplify(ExpressionVisitor visitor)
Simplify the expression
|
Expression |
typeCheck(ExpressionVisitor visitor,
ItemType contextItemType)
Type-check the expression
|
displayOperator, getBaseExpression, iterateSubExpressions, promote, replaceSubExpression, toString
addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, evaluateAsString, evaluatePendingUpdates, explain, getCardinality, getColumnNumber, getColumnNumber, getConstructType, getContainer, getDependencies, getEvaluationMethod, getExecutable, getExpressionName, getHostLanguage, getImplementationMethod, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterate, iterateEvents, iterateSameFocusSubExpressions, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setEvaluationMethod, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, typeError
AtomicType targetType
boolean allowEmpty
public CastableExpression(Expression source, AtomicType target, boolean allowEmpty)
source
- The source expressiontarget
- The type being tested againstallowEmpty
- true if an empty sequence is acceptable, that is if the expression
was written as "source castable as target?"public AtomicType getTargetType()
public boolean allowsEmpty()
public Expression simplify(ExpressionVisitor visitor) throws XPathException
simplify
in class UnaryExpression
visitor
- an expression visitorXPathException
- if an error is discovered during expression
rewritingpublic 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
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(Object other)
equals
in class UnaryExpression
public int hashCode()
hashCode
in class UnaryExpression
public ItemType getItemType(TypeHierarchy th)
getItemType
in class UnaryExpression
th
- the type hierarchy cachepublic int computeCardinality()
UnaryExpression
computeCardinality
in class UnaryExpression
StaticProperty.ALLOWS_ZERO_OR_ONE
,
StaticProperty.EXACTLY_ONE
, StaticProperty.ALLOWS_ONE_OR_MORE
,
StaticProperty.ALLOWS_ZERO_OR_MORE
public int computeSpecialProperties()
computeSpecialProperties
in class UnaryExpression
StaticProperty.NON_CREATIVE
.public Expression copy()
copy
in class Expression
public 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
Expression
effectiveBooleanValue
in class Expression
context
- The context in which the expression is to be evaluatedXPathException
- if any dynamic error occurs evaluating the
expressionpublic static boolean isCastable(AtomicValue value, AtomicType targetType, XPathContext context)
value
- the value to be testedtargetType
- the type to be tested againstcontext
- XPath dynamic contextpublic void explain(ExpressionPresenter out)
explain
in class UnaryExpression
out
- the expression presenter used to display the structure