Package net.sf.saxon.expr
Class GeneralComparison10
- java.lang.Object
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- net.sf.saxon.expr.Expression
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- net.sf.saxon.expr.BinaryExpression
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- net.sf.saxon.expr.GeneralComparison10
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- All Implemented Interfaces:
java.io.Serializable
,javax.xml.transform.SourceLocator
,LocationProvider
,SaxonLocator
,CallableExpression
,InstructionInfo
,org.xml.sax.Locator
public class GeneralComparison10 extends BinaryExpression implements CallableExpression
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:
- Serialized Form
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Field Summary
Fields Modifier and Type Field Description protected AtomicComparer
comparer
protected int
singletonOperator
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Fields inherited from class net.sf.saxon.expr.BinaryExpression
operand0, operand1, operator
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Fields inherited from class net.sf.saxon.expr.Expression
EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, EVENT_FEED_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, locationId, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, PUSH_SELECTION, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, WATCH_METHOD
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Constructor Summary
Constructors Constructor Description GeneralComparison10(Expression p0, int op, Expression p1)
Create a general comparison identifying the two operands and the operator
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description SequenceIterator
call(SequenceIterator[] arguments, XPathContext context)
Evaluate the expression: interface for use by compiled bytecodeint
computeCardinality()
Determine the static cardinality.Expression
copy()
Copy an expression.boolean
effectiveBooleanValue(XPathContext context)
Evaluate the expression giving a boolean resultItem
evaluateItem(XPathContext context)
Evaluate the expression in a given contextprotected void
explainExtraAttributes(ExpressionPresenter out)
Add subclass-specific attributes to the expression tree explanation.ItemType
getItemType(TypeHierarchy th)
Determine the data type of the expressionExpression
optimize(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType)
Optimize the expressionvoid
setAtomicComparer(AtomicComparer comparer)
Expression
typeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType)
Type-check the expression-
Methods inherited from class net.sf.saxon.expr.BinaryExpression
computeSpecialProperties, displayOperator, equals, explain, getArguments, getOperands, getOperator, hashCode, isAssociative, isCommutative, isInverse, iterateSubExpressions, promote, replaceSubExpression, setFlattened, simplify, toString
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Methods inherited from class net.sf.saxon.expr.Expression
addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, evaluateAsString, evaluatePendingUpdates, explain, getCardinality, getColumnNumber, getColumnNumber, getConstructType, getContainer, getDependencies, getEvaluationMethod, getExecutable, getExpressionName, getHostLanguage, getImplementationMethod, getIntegerBounds, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, hasVariableBinding, implementsStaticTypeCheck, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterate, iterateEvents, iterateSameFocusSubExpressions, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setEvaluationMethod, setFiltered, setLocationId, staticTypeCheck, suppressValidation, typeError
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Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
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Methods inherited from interface net.sf.saxon.expr.CallableExpression
getArguments
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Field Detail
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singletonOperator
protected int singletonOperator
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comparer
protected AtomicComparer comparer
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Constructor Detail
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GeneralComparison10
public GeneralComparison10(Expression p0, int op, Expression p1)
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 Detail
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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, ExpressionVisitor.ContextItemType 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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setAtomicComparer
public void setAtomicComparer(AtomicComparer comparer)
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optimize
public Expression optimize(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType 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
public Item evaluateItem(XPathContext context) throws XPathException
Evaluate the expression in a given context- 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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call
public SequenceIterator call(SequenceIterator[] arguments, XPathContext context) throws XPathException
Evaluate the expression: interface for use by compiled bytecode- Specified by:
call
in interfaceCallableExpression
- Parameters:
arguments
- the values of the arguments, supplied as SequenceIteratorscontext
- the dynamic evaluation context- Returns:
- the result of the evaluation, in the form of a SequenceIterator
- Throws:
XPathException
- if a dynamic error occurs during the evaluation of the expression
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effectiveBooleanValue
public boolean effectiveBooleanValue(XPathContext context) throws XPathException
Evaluate the expression giving a boolean result- Overrides:
effectiveBooleanValue
in classExpression
- Parameters:
context
- the given context for evaluation- Returns:
- a boolean representing the result of the comparison of the two operands
- Throws:
XPathException
- if any dynamic error occurs evaluating the expression
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copy
public Expression 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
public ItemType getItemType(TypeHierarchy th)
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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explainExtraAttributes
protected void explainExtraAttributes(ExpressionPresenter out)
Description copied from class:BinaryExpression
Add subclass-specific attributes to the expression tree explanation. Default implementation does nothing; this is provided for subclasses to override.- Overrides:
explainExtraAttributes
in classBinaryExpression
- Parameters:
out
- the output destination for the displayed expression tree
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