Package net.sf.saxon.expr
Class UntypedAtomicConverter
java.lang.Object
net.sf.saxon.expr.Expression
net.sf.saxon.expr.UnaryExpression
net.sf.saxon.expr.UntypedAtomicConverter
- All Implemented Interfaces:
Serializable
,SourceLocator
,LocationProvider
,SaxonLocator
,EvaluableItem
,SequenceIterable
,InstructionInfo
,Locator
An UntypedAtomicConverter is an expression that converts any untypedAtomic items in
a sequence to a specified type
- See Also:
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Field Summary
Fields inherited from class net.sf.saxon.expr.UnaryExpression
operand
Fields inherited from class net.sf.saxon.expr.Expression
EVALUATE_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties
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Constructor Summary
ConstructorsConstructorDescriptionUntypedAtomicConverter
(Expression sequence, AtomicType requiredItemType, boolean allConverted) Constructor -
Method Summary
Modifier and TypeMethodDescriptionboolean
Determine whether all items are to be converted, or only the subset that are untypedAtomicint
Determine the static cardinality.int
Determine the special properties of this expressioncopy()
Copy an expression.protected String
displayOperator
(Configuration config) Give a string representation of the operator for use in diagnosticsevaluateItem
(XPathContext context) Evaluate as an Item.void
Diagnostic print of expression structure.Determine the data type of the items returned by the expressionGet the item type to which untyped atomic items must be convertediterate
(XPathContext context) Iterate over the sequence of valuestypeCheck
(ExpressionVisitor visitor, ItemType contextItemType) Type-check the expressionMethods inherited from class net.sf.saxon.expr.UnaryExpression
displayExpressionName, equals, getBaseExpression, hashCode, iterateSubExpressions, optimize, promote, replaceSubExpression, simplify, toString
Methods inherited from class net.sf.saxon.expr.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, iterateEvents, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, typeError
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Constructor Details
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UntypedAtomicConverter
public UntypedAtomicConverter(Expression sequence, AtomicType requiredItemType, boolean allConverted) Constructor- Parameters:
sequence
- this must be a sequence of atomic values. This is not checked; a ClassCastException will occur if the precondition is not satisfied.requiredItemType
- the item type to which untypedAtomic items in the sequence should be converted, using the rules for "cast as".allConverted
- true if the result of this expression is a sequence in which all items belong to the required type
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Method Details
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getRequiredItemType
Get the item type to which untyped atomic items must be converted- Returns:
- the required item type
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areAllItemsConverted
public boolean areAllItemsConverted()Determine whether all items are to be converted, or only the subset that are untypedAtomic- Returns:
- true if all items are to be converted
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getItemType
Determine the data type of the items returned by the expression- Overrides:
getItemType
in classUnaryExpression
- Parameters:
th
- the type hierarchy cache- Returns:
- the item type of the items in the result sequence, insofar as this is known statically.
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computeCardinality
public int computeCardinality()Description copied from class:UnaryExpression
Determine the static cardinality. Default implementation returns the cardinality of the operand- Overrides:
computeCardinality
in classUnaryExpression
- Returns:
- the computed cardinality, as one of the values
StaticProperty.ALLOWS_ZERO_OR_ONE
,StaticProperty.EXACTLY_ONE
,StaticProperty.ALLOWS_ONE_OR_MORE
,StaticProperty.ALLOWS_ZERO_OR_MORE
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typeCheck
public Expression typeCheck(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException Type-check the expression- Overrides:
typeCheck
in classUnaryExpression
- Parameters:
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 toType.ITEM_TYPE
- Returns:
- the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
- Throws:
XPathException
- if an error is discovered during this phase (typically a type error)
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computeSpecialProperties
public int computeSpecialProperties()Determine the special properties of this expression- Overrides:
computeSpecialProperties
in classUnaryExpression
- Returns:
StaticProperty.NON_CREATIVE
.
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copy
Copy an expression. This makes a deep copy.- Specified by:
copy
in classExpression
- Returns:
- the copy of the original expression
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iterate
Iterate over the sequence of values- Specified by:
iterate
in interfaceSequenceIterable
- Overrides:
iterate
in classExpression
- Parameters:
context
- supplies the context for evaluation- Returns:
- a SequenceIterator that can be used to iterate over the result of the expression
- Throws:
XPathException
- if any dynamic error occurs evaluating the expression
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evaluateItem
Evaluate as an Item. This should only be called if the UntypedAtomicConverter has cardinality zero-or-one- Specified by:
evaluateItem
in interfaceEvaluableItem
- Overrides:
evaluateItem
in classExpression
- Parameters:
context
- The context in which the expression is to be evaluated- Returns:
- the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence
- Throws:
XPathException
- if any dynamic error occurs evaluating the expression
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explain
Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.- Overrides:
explain
in classUnaryExpression
- Parameters:
out
- the expression presenter used to display the structure
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displayOperator
Description copied from class:UnaryExpression
Give a string representation of the operator for use in diagnostics- Overrides:
displayOperator
in classUnaryExpression
- Parameters:
config
-- Returns:
- the operator, as a string
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