Package net.sf.saxon.expr
Class UntypedAtomicConverter
java.lang.Object
net.sf.saxon.expr.ComputedExpression
net.sf.saxon.expr.UnaryExpression
net.sf.saxon.expr.UntypedAtomicConverter
- All Implemented Interfaces:
Serializable
,SourceLocator
,Container
,Expression
,InstructionInfoProvider
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.ComputedExpression
locationId, staticProperties
Fields inherited from interface net.sf.saxon.expr.Expression
EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD
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Constructor Summary
ConstructorsConstructorDescriptionUntypedAtomicConverter
(Expression sequence, AtomicType requiredItemType, boolean allConverted) Constructor -
Method Summary
Modifier and TypeMethodDescriptionint
Determine the special properties of this expressionprotected String
displayOperator
(Configuration config) Give a string representation of the operator for use in diagnosticsevaluateItem
(XPathContext context) Evaluate as an Item.Determine the data type of the items returned by the expressioniterate
(XPathContext context) Iterate over the sequence of valuestypeCheck
(StaticContext env, ItemType contextItemType) Type-check the expressionMethods inherited from class net.sf.saxon.expr.UnaryExpression
computeCardinality, display, equals, getBaseExpression, hashCode, iterateSubExpressions, optimize, promote, replaceSubExpression, simplify
Methods inherited from class net.sf.saxon.expr.ComputedExpression
adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, getCardinality, getColumnNumber, getConstructType, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, markTailFunctionCalls, process, resetStaticProperties, setLocationId, setParentExpression, setParentExpression, 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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getItemType
Determine the data type of the items returned by the expression- Specified by:
getItemType
in interfaceExpression
- Overrides:
getItemType
in classUnaryExpression
- Parameters:
th
-- Returns:
- the item type of the items in the result sequence, insofar as this is known statically.
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typeCheck
Type-check the expression- Specified by:
typeCheck
in interfaceExpression
- Overrides:
typeCheck
in classUnaryExpression
- Parameters:
env
- the static context of the expressioncontextItemType
- 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
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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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iterate
Iterate over the sequence of values- Specified by:
iterate
in interfaceExpression
- Overrides:
iterate
in classComputedExpression
- 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 interfaceExpression
- Overrides:
evaluateItem
in classComputedExpression
- 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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displayOperator
Give a string representation of the operator for use in diagnostics- Specified by:
displayOperator
in classUnaryExpression
- Parameters:
config
-- Returns:
- the operator, as a string
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