public class CastExpression extends CastingExpression implements Callable
converter
EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, UPDATE_METHOD, WATCH_METHOD
Constructor and Description |
---|
CastExpression(Expression source,
AtomicType target,
boolean allowEmpty)
Create a cast expression
|
Modifier and Type | Method and Description |
---|---|
Sequence |
call(XPathContext context,
Sequence[] arguments)
Call the Callable.
|
int |
computeCardinality()
Get the static cardinality of the expression
|
int |
computeHashCode()
get HashCode for comparing two expressions.
|
int |
computeSpecialProperties()
Determine the special properties of this expression
|
Expression |
copy(RebindingMap rebindings)
Copy an expression.
|
boolean |
equals(java.lang.Object other)
Is this expression the same as another expression?
|
AtomicValue |
evaluateItem(XPathContext context)
Evaluate the expression
|
void |
export(ExpressionPresenter out)
Diagnostic print of expression structure.
|
java.lang.String |
getExpressionName()
Get a name identifying the kind of expression, in terms meaningful to a user.
|
int |
getImplementationMethod()
An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process().
|
IntegerValue[] |
getIntegerBounds()
For an expression that returns an integer or a sequence of integers, get
a lower and upper bound on the values of the integers that may be returned, from
static analysis.
|
ItemType |
getItemType()
Get the static type of the expression
/*@NotNull
|
UType |
getStaticUType(UType contextItemType)
Get the static type of the expression as a UType, following precisely the type
inference rules defined in the XSLT 3.0 specification.
|
Expression |
optimize(ExpressionVisitor visitor,
ContextItemStaticInfo contextInfo)
Perform optimisation of an expression and its subexpressions.
|
protected Expression |
preEvaluate()
Perform early (compile-time) evaluation
|
java.lang.String |
toShortString()
Produce a short string identifying the expression for use in error messages
|
java.lang.String |
toString()
Represent the expression as a string.
|
Expression |
typeCheck(ExpressionVisitor visitor,
ContextItemStaticInfo contextInfo)
Type-check the expression
|
allowsEmpty, getConverter, getIntrinsicDependencies, getNamespaceResolver, getOperandRole, getTargetPrimitiveType, getTargetType, isOperandIsStringLiteral, setAllowEmpty, setOperandIsStringLiteral, setTargetType, simplify
displayOperator, getBaseExpression, getOperand, operands, setBaseExpression
addToPathMap, adoptChildExpression, allowExtractingCommonSubexpressions, checkedOperands, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, dynamicError, effectiveBooleanValue, evaluateAsString, evaluatePendingUpdates, explain, getCardinality, getConfiguration, getConstructType, getCost, getDependencies, getEvaluationMethod, getExtraProperty, getInterpretedExpression, getLocalRetainedStaticContext, getLocation, getNetCost, getObjectName, getPackageData, getParentExpression, getProperties, getProperty, getRetainedStaticContext, getScopingExpression, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStaticType, getStreamerName, hasCompatibleStaticContext, hashCode, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isCallOnSystemFunction, isIdentical, isInstruction, isLiftable, isMultiThreaded, isSameExpression, isStaticPropertiesKnown, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterate, markTailFunctionCalls, operandList, operandSparseList, optimizeChildren, process, resetLocalStaticProperties, restoreParentPointers, setEvaluationMethod, setExtraProperty, setFiltered, setFlattened, setLocation, setParentExpression, setRetainedStaticContext, setRetainedStaticContextLocally, setRetainedStaticContextThoroughly, setStaticProperty, simplifyChildren, staticTypeCheck, suppressValidation, toPattern, typeCheckChildren, typeError, unordered, verifyParentPointers, verifyParentPointers
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 Expression typeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) throws XPathException
typeCheck
in class UnaryExpression
visitor
- an expression visitorcontextInfo
- Information available statically about the context item: whether it is (possibly)
absent; its static type; its streaming posture.XPathException
- if an error is discovered during this phase
(typically a type error)public Expression optimize(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) 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 class UnaryExpression
visitor
- an expression visitorcontextInfo
- 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)protected Expression preEvaluate() throws XPathException
XPathException
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()
getItemType
in class UnaryExpression
public UType getStaticUType(UType contextItemType)
getStaticUType
in class Expression
contextItemType
- public int computeSpecialProperties()
computeSpecialProperties
in class CastingExpression
public IntegerValue[] getIntegerBounds()
getIntegerBounds
in class Expression
public Expression copy(RebindingMap rebindings)
copy
in class Expression
rebindings
- public int getImplementationMethod()
getImplementationMethod
in class Expression
Expression.ITERATE_METHOD
or Expression.EVALUATE_METHOD
or
Expression.PROCESS_METHOD
public Sequence call(XPathContext context, Sequence[] arguments) throws XPathException
Callable
call
in interface Callable
context
- the dynamic evaluation contextarguments
- the values of the arguments, supplied as Sequences.
Generally it is advisable, if calling iterate() to process a supplied sequence, to
call it only once; if the value is required more than once, it should first be converted
to a GroundedValue
by calling the utility method
SequenceTool.toGroundedValue().
If the expected value is a single item, the item should be obtained by calling
Sequence.head(): it cannot be assumed that the item will be passed as an instance of
Item
or AtomicValue
.
It is the caller's responsibility to perform any type conversions required to convert arguments to the type expected by the callee. An exception is where this Callable is explicitly an argument-converting wrapper around the original Callable.
XPathException
- if a dynamic error occurs during the evaluation of the expressionpublic AtomicValue evaluateItem(XPathContext context) throws XPathException
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 int computeHashCode()
computeHashCode
in class UnaryExpression
public java.lang.String toString()
toString
in class UnaryExpression
public java.lang.String toShortString()
Expression
toShortString
in class UnaryExpression
public void export(ExpressionPresenter out) throws XPathException
export
in interface ExportAgent
export
in class UnaryExpression
out
- the expression presenter used to display the structureXPathException
- if the export fails, for example if an expression is found that won't work
in the target environment.public java.lang.String getExpressionName()
getExpressionName
in class Expression
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