public final class AtomicSequenceConverter extends UnaryExpression implements MappingFunction
operand
locationId, staticProperties
EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD
Constructor and Description |
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AtomicSequenceConverter(Expression sequence,
AtomicType requiredItemType)
Constructor
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Modifier and Type | Method and Description |
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int |
computeCardinality()
Determine the static cardinality of the expression
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int |
computeSpecialProperties()
Determine the special properties of this expression
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protected String |
displayOperator(NamePool pool)
Give a string representation of the operator for use in diagnostics
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boolean |
equals(Object other)
Is this expression the same as another expression?
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Item |
evaluateItem(XPathContext context)
Evaluate as an Item.
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ItemType |
getItemType(TypeHierarchy th)
Determine the data type of the items returned by the expression, if possible
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SequenceIterator |
iterate(XPathContext context)
Iterate over the sequence of values
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Object |
map(Item item,
XPathContext context)
Implement the mapping function
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Expression |
simplify(StaticContext env)
Simplify an expression
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Expression |
typeCheck(StaticContext env,
ItemType contextItemType)
Type-check the expression
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display, getBaseExpression, hashCode, iterateSubExpressions, optimize, promote
adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, 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, suppressValidation, typeError, typeError
public AtomicSequenceConverter(Expression sequence, AtomicType requiredItemType)
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 all items in the sequence should be converted,
using the rules for "cast as".public Expression simplify(StaticContext env) throws XPathException
simplify
in interface Expression
simplify
in class UnaryExpression
XPathException
- if an error is discovered during expression
rewritingpublic Expression typeCheck(StaticContext env, ItemType contextItemType) throws XPathException
typeCheck
in interface Expression
typeCheck
in class UnaryExpression
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 to
Type.ITEM_TYPE
StaticError
- if an error is discovered during this phase
(typically a type error)XPathException
public int computeSpecialProperties()
computeSpecialProperties
in class UnaryExpression
StaticProperty.NON_CREATIVE
.public SequenceIterator iterate(XPathContext context) throws XPathException
iterate
in interface Expression
iterate
in class ComputedExpression
context
- supplies the context for evaluationXPathException
- if any dynamic error occurs evaluating the
expressionpublic Item evaluateItem(XPathContext context) throws XPathException
evaluateItem
in interface Expression
evaluateItem
in class ComputedExpression
context
- The context in which the expression is to be evaluatedXPathException
- if any dynamic error occurs evaluating the
expressionpublic Object map(Item item, XPathContext context) throws XPathException
map
in interface MappingFunction
item
- The item to be mapped.
If context is supplied, this must be the same as context.currentItem().context
- The processing context. Some mapping functions use this because they require
context information. Some mapping functions modify the context by maintaining the context item
and position. In other cases, the context may be null.XPathException
public ItemType getItemType(TypeHierarchy th)
getItemType
in interface Expression
getItemType
in class UnaryExpression
th
- public int computeCardinality()
computeCardinality
in class UnaryExpression
public boolean equals(Object other)
equals
in class UnaryExpression
protected String displayOperator(NamePool pool)
displayOperator
in class UnaryExpression