java.io.Serializable
, javax.xml.transform.SourceLocator
, LocationProvider
, SaxonLocator
, EvaluableItem
, SequenceIterable
, InstructionInfo
, org.xml.sax.Locator
public final class CastExpression extends UnaryExpression
EVALUATE_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties
operand
Constructor | Description |
---|---|
CastExpression(Expression source,
AtomicType target,
boolean allowEmpty) |
Create a cast expression
|
Modifier and Type | Method | Description |
---|---|---|
boolean |
allowsEmpty() |
Ask whether the expression accepts an empty sequence as input (producing an empty sequence as output)
|
static AtomicValue |
castStringToQName(java.lang.CharSequence operand,
AtomicType targetType,
StaticContext env) |
Evaluate the "pseudo-cast" of a string literal to a QName or NOTATION value.
|
int |
computeCardinality() |
Get the static cardinality of the expression
|
int |
computeSpecialProperties() |
Determine the special properties of this expression
|
Expression |
copy() |
Copy an expression.
|
boolean |
equals(java.lang.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) |
Get the static type of the expression
|
AtomicType |
getTargetPrimitiveType() |
Get the primitive base type of the target type of the cast
|
AtomicType |
getTargetType() |
Get the target type (the result type)
|
static boolean |
isPossibleCast(int source,
int target) |
Determine whether casting from a source type to a target type is possible
|
boolean |
isUpCast() |
Ask whether this is a cast to a supertype of the original type
|
Expression |
simplify(ExpressionVisitor visitor) |
Simplify the expression
|
boolean |
targetIsDerived() |
Ask whether the target type is a derived type (not a primitive type)
|
java.lang.String |
toString() |
The toString() method for an expression attempts to give a representation of the expression
in an XPath-like form, but there is no guarantee that the syntax will actually be true XPath.
|
Expression |
typeCheck(ExpressionVisitor visitor,
ItemType contextItemType) |
Type-check the expression
|
addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, display, doPromotion, dynamicError, effectiveBooleanValue, 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
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
displayExpressionName, displayOperator, getBaseExpression, hashCode, iterateSubExpressions, optimize, promote, replaceSubExpression
public CastExpression(Expression source, AtomicType target, boolean allowEmpty)
source
- expression giving the value to be convertedtarget
- the type to which the value is to be convertedallowEmpty
- true if the expression allows an empty sequence as input, producing
an empty sequence as output. If false, an empty sequence is a type error.public static boolean isPossibleCast(int source, int target)
source
- a primitive type (one that has an entry in the casting table)target
- another primitive typepublic AtomicType getTargetPrimitiveType()
public AtomicType getTargetType()
public boolean allowsEmpty()
public boolean targetIsDerived()
public boolean isUpCast()
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 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 ItemType getItemType(TypeHierarchy th)
getItemType
in class UnaryExpression
th
- the type hierarchy cachepublic 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 equals(java.lang.Object other)
equals
in class UnaryExpression
public java.lang.String toString()
toString
in class UnaryExpression
public void explain(ExpressionPresenter out)
explain
in class UnaryExpression
out
- the expression presenter used to display the structurepublic static AtomicValue castStringToQName(java.lang.CharSequence operand, AtomicType targetType, StaticContext env) throws XPathException
operand
- the value to be convertedtargetType
- the type to which it is to be convertedenv
- the static contextXPathException