Package net.sf.saxon.expr
Class GeneralComparison10
java.lang.Object
net.sf.saxon.expr.Expression
net.sf.saxon.expr.BinaryExpression
net.sf.saxon.expr.GeneralComparison10
- All Implemented Interfaces:
Serializable
,SourceLocator
,LocationProvider
,SaxonLocator
,EvaluableItem
,SequenceIterable
,InstructionInfo
,Locator
GeneralComparison10: a boolean expression that compares two expressions
for equals, not-equals, greater-than or less-than. This implements the operators
=, !=, <, >, etc. This version of the class implements general comparisons
in XPath 1.0 backwards compatibility mode, as defined in the Oct 2004 revision
of the specifications.
- See Also:
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Field Summary
FieldsFields inherited from class net.sf.saxon.expr.BinaryExpression
operand0, operand1, operator
Fields inherited from class net.sf.saxon.expr.Expression
EVALUATE_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties
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Constructor Summary
ConstructorsConstructorDescriptionGeneralComparison10
(Expression p0, int op, Expression p1) Create a general comparison identifying the two operands and the operator -
Method Summary
Modifier and TypeMethodDescriptionint
Determine the static cardinality.copy()
Copy an expression.protected String
boolean
effectiveBooleanValue
(XPathContext context) Evaluate the expression in a boolean contextevaluateItem
(XPathContext context) Evaluate the expression in a given contextDetermine the data type of the expressionoptimize
(ExpressionVisitor visitor, ItemType contextItemType) Optimize the expressiontypeCheck
(ExpressionVisitor visitor, ItemType contextItemType) Type-check the expressionMethods inherited from class net.sf.saxon.expr.BinaryExpression
computeSpecialProperties, equals, explain, getOperands, getOperator, hashCode, isAssociative, isCommutative, isInverse, iterateSubExpressions, promote, replaceSubExpression, setFlattened, simplify, toString
Methods inherited from class net.sf.saxon.expr.Expression
addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, display, doPromotion, dynamicError, 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, iterate, iterateEvents, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setFiltered, setLocationId, staticTypeCheck, suppressValidation, typeError
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Field Details
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singletonOperator
protected int singletonOperator -
comparer
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Constructor Details
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GeneralComparison10
Create a general comparison identifying the two operands and the operator- Parameters:
p0
- the left-hand operandop
- the operator, as a token returned by the Tokenizer (e.g. Token.LT)p1
- the right-hand operand
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Method Details
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computeCardinality
public int computeCardinality()Determine the static cardinality. Returns [1..1]- Overrides:
computeCardinality
in classBinaryExpression
- 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 classBinaryExpression
- 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 checked expression
- Throws:
XPathException
- if an error is discovered during this phase (typically a type error)
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optimize
public Expression optimize(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException Optimize the expression- Overrides:
optimize
in classBinaryExpression
- 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 checked expression
- Throws:
XPathException
- if an error is discovered during this phase (typically a type error)
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evaluateItem
Evaluate the expression in a given context- Specified by:
evaluateItem
in interfaceEvaluableItem
- Overrides:
evaluateItem
in classExpression
- Parameters:
context
- the given context for evaluation- Returns:
- a BooleanValue representing the result of the numeric comparison of the two operands
- Throws:
XPathException
- if any dynamic error occurs evaluating the expression
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effectiveBooleanValue
Evaluate the expression in a boolean context- Overrides:
effectiveBooleanValue
in classExpression
- Parameters:
context
- the given context for evaluation- Returns:
- a boolean representing the result of the numeric comparison of the two operands
- Throws:
XPathException
- if any dynamic error occurs evaluating the expression
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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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getItemType
Determine the data type of the expression- Specified by:
getItemType
in classExpression
- Parameters:
th
- the type hierarchy cache- Returns:
- Type.BOOLEAN
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displayOperator
- Overrides:
displayOperator
in classBinaryExpression
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