public class RangeExpression extends BinaryExpression
From Saxon 7.8, the sequence must be ascending; if the end-point is less than the start-point, an empty sequence is returned. This is to allow expressions of the form "for $i in 1 to count($seq) return ...."
operand0, operand1, operator
EVALUATE_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties
?????? |
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RangeExpression(Expression start,
int op,
Expression end)
Construct a RangeExpression
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?????? | ????? |
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int |
computeCardinality()
Determine the static cardinality
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Expression |
copy()
Copy an expression.
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ItemType |
getItemType(TypeHierarchy th)
Get the data type of the items returned
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SequenceIterator |
iterate(XPathContext context)
Return an iteration over the sequence
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Expression |
optimize(ExpressionVisitor visitor,
ItemType contextItemType)
Perform optimisation of an expression and its subexpressions.
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Expression |
typeCheck(ExpressionVisitor visitor,
ItemType contextItemType)
Type-check the expression
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computeSpecialProperties, displayOperator, equals, explain, getOperands, getOperator, hashCode, isAssociative, isCommutative, isInverse, iterateSubExpressions, promote, replaceSubExpression, setFlattened, simplify, toString
addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, display, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, 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, setLocationId, staticTypeCheck, suppressValidation, typeError
public RangeExpression(Expression start, int op, Expression end)
start
- expression that computes the start of the rangeop
- represents the operator "to", needed only because this class is a subclass of
BinaryExpression which needs an operatorend
- expression that computes the end of the rangepublic Expression typeCheck(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException
typeCheck
??? BinaryExpression
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 Expression optimize(ExpressionVisitor visitor, ItemType contextItemType) 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
??? BinaryExpression
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 ItemType getItemType(TypeHierarchy th)
getItemType
??? Expression
th
- the type hierarchy cachepublic int computeCardinality()
computeCardinality
??? BinaryExpression
StaticProperty.ALLOWS_ZERO_OR_ONE
,
StaticProperty.EXACTLY_ONE
, StaticProperty.ALLOWS_ONE_OR_MORE
,
StaticProperty.ALLOWS_ZERO_OR_MORE
public Expression copy()
copy
??? Expression
public SequenceIterator iterate(XPathContext context) throws XPathException
iterate
???? SequenceIterable
iterate
??? Expression
context
- supplies the context for evaluationXPathException
- if any dynamic error occurs evaluating the
expression