public final class CastableExpression extends UnaryExpression
operand
EVALUATE_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties
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CastableExpression(Expression source,
AtomicType target,
boolean allowEmpty)
Create a "castable" expression of the form "source castable as target"
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boolean |
allowsEmpty()
Determine whether the empty sequence is allowed
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int |
computeCardinality()
Determine the static cardinality.
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int |
computeSpecialProperties()
Determine the special properties of this expression
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Expression |
copy()
Copy an expression.
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boolean |
effectiveBooleanValue(XPathContext context)
Get the effective boolean value of the expression.
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boolean |
equals(java.lang.Object other)
Is this expression the same as another expression?
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Item |
evaluateItem(XPathContext context)
Evaluate the expression
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void |
explain(ExpressionPresenter out)
Diagnostic print of expression structure.
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ItemType |
getItemType(TypeHierarchy th)
Determine the data type of the result of the Castable expression
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AtomicType |
getTargetType()
Get the target type
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static boolean |
isCastable(AtomicValue value,
AtomicType targetType,
XPathContext context)
Determine whether a value is castable to a given type
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Expression |
optimize(ExpressionVisitor visitor,
ItemType contextItemType)
Optimize the expression
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Expression |
simplify(ExpressionVisitor visitor)
Simplify the expression
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Expression |
typeCheck(ExpressionVisitor visitor,
ItemType contextItemType)
Type-check the expression
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displayExpressionName, displayOperator, getBaseExpression, hashCode, iterateSubExpressions, promote, replaceSubExpression, 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 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
??? UnaryExpression
visitor
- an expression visitorXPathException
- if an error is discovered during expression
rewritingpublic Expression typeCheck(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException
typeCheck
??? 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
??? 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
??? UnaryExpression
public ItemType getItemType(TypeHierarchy th)
getItemType
??? UnaryExpression
th
- the type hierarchy cachepublic int computeCardinality()
UnaryExpression
computeCardinality
??? UnaryExpression
StaticProperty.ALLOWS_ZERO_OR_ONE
,
StaticProperty.EXACTLY_ONE
, StaticProperty.ALLOWS_ONE_OR_MORE
,
StaticProperty.ALLOWS_ZERO_OR_MORE
public int computeSpecialProperties()
public Expression copy()
copy
??? Expression
public Item evaluateItem(XPathContext context) throws XPathException
evaluateItem
???? EvaluableItem
evaluateItem
??? 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
??? 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
??? UnaryExpression
out
- the expression presenter used to display the structure