com.saxonica.ee.optim

Class GeneralComparisonEE

java.lang.Object

net.sf.saxon.expr.Expression

net.sf.saxon.expr.BinaryExpression

net.sf.saxon.expr.GeneralComparison

com.saxonica.ee.optim.GeneralComparisonEE

All Implemented Interfaces:

SourceLocator, Callable, ComparisonExpression, IdentityComparable, InstructionInfo

public class GeneralComparisonEE
extends GeneralComparison

This class provides an implementation of the GeneralComparison "=" operator, which deals efficiently with comparing two sequences.

Field Summary

Fields inherited from class net.sf.saxon.expr.GeneralComparison

comparer, comparisonCardinality, MANY_TO_MANY, MANY_TO_ONE, needsRuntimeCheck, ONE_TO_ONE, singletonOperator

Fields inherited from class net.sf.saxon.expr.BinaryExpression

operand0, operand1, operator

Fields inherited from class net.sf.saxon.expr.Expression

EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, locationId, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, WATCH_METHOD

Constructor Summary

Constructors

Constructor and Description
GeneralComparisonEE(Expression p0, int op, Expression p1) Create a relational expression identifying the two operands and the operator

Method Summary

Methods

Modifier and Type	Method and Description
Expression	copy() Copy an expression.
boolean	effectiveBooleanValue(XPathContext context) Evaluate the expression in a boolean context
protected void	explainExtraAttributes(ExpressionPresenter out) Add subclass-specific attributes to the expression tree explanation.
protected GeneralComparison	getInverseComparison()
Expression	optimize(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType) Optimize the expression

Methods inherited from class net.sf.saxon.expr.GeneralComparison

call, compare, computeCardinality, convertsUntypedToOther, evaluateItem, evaluateManyToMany, getAtomicComparer, getComparisonCardinality, getCorrespondingSingletonOperator, getExpressionCompiler, getExpressionName, getItemType, getSingletonOperator, getStreamingAdjunct, needsRuntimeCheck, quickCompare, setAtomicComparer, setComparisonCardinality, setNeedsRuntimeCheck, simplify, typeCheck

Methods inherited from class net.sf.saxon.expr.BinaryExpression

computeSpecialProperties, displayOperator, equals, explain, getArguments, getOperands, getOperator, hashCode, isAssociative, isCommutative, isInverse, operands, promote, replaceOperand, setFlattened, toShortString, toString

Methods inherited from class net.sf.saxon.expr.Expression

addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, clearStreamabilityData, computeDependencies, computeStaticProperties, doPromotion, dynamicError, evaluateAsString, evaluatePendingUpdates, explain, getCardinality, getColumnNumber, getConfiguration, getConstructType, getContainer, getDependencies, getEvaluationMethod, getHostLanguage, getImplementationMethod, getIntegerBounds, getIntrinsicDependencies, getLineNumber, getLocationId, getObjectName, getPosture, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getStreamability, getSweep, getSystemId, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isIdentical, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterate, iterateEvents, makeStreamingAdjunct, markTailFunctionCalls, operandList, process, resetLocalStaticProperties, setContainer, setEvaluationMethod, setFiltered, setLocationId, setPostureAndSweep, staticTypeCheck, suppressValidation, toPattern, toStreamingPattern, typeError, unordered

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface net.sf.saxon.expr.ComparisonExpression

getOperands

Constructor Detail

GeneralComparisonEE

public GeneralComparisonEE(Expression p0,
                   int op,
                   Expression p1)

Create a relational expression identifying the two operands and the operator

Parameters:

p0 - the left-hand operand

op - the operator, as a token returned by the Tokenizer (e.g. Token.LT)

p1 - the right-hand operand

Method Detail

optimize

public Expression optimize(ExpressionVisitor visitor,
                  ContextItemStaticInfo contextItemType)
                    throws XPathException

Description copied from class: GeneralComparison

Optimize the expression

Overrides:

optimize in class GeneralComparison

Parameters:

visitor - an expression visitor

contextItemType - 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

Returns:

the checked expression

Throws:

XPathException - if an error is discovered during this phase (typically a type error)

copy

public Expression copy()

Description copied from class: GeneralComparison

Copy an expression. This makes a deep copy.

Overrides:

copy in class GeneralComparison

Returns:

the copy of the original expression

effectiveBooleanValue

public boolean effectiveBooleanValue(XPathContext context)
                              throws XPathException

Evaluate the expression in a boolean context

Overrides:

effectiveBooleanValue in class GeneralComparison

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

getInverseComparison

protected GeneralComparison getInverseComparison()

Overrides:

getInverseComparison in class GeneralComparison

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 class GeneralComparison

Parameters:

out - the output destination for the displayed expression tree