Package com.saxonica.ee.optim

Class GeneralEqualityEE

java.lang.Object

net.sf.saxon.expr.Expression

net.sf.saxon.expr.BinaryExpression

net.sf.saxon.expr.GeneralComparison

com.saxonica.ee.optim.GeneralEqualityEE

All Implemented Interfaces:

ComparisonExpression, ExportAgent, Locatable, IdentityComparable, Traceable

public class GeneralEqualityEE
extends GeneralComparison

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

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	GeneralEqualityEE.GeneralEqualityElaboratorEE	Elaborator for a general comparison expression such as (A = B).

Nested classes/interfaces inherited from class net.sf.saxon.expr.GeneralComparison

GeneralComparison.ComparisonCardinality, GeneralComparison.GeneralComparisonElaborator

Field Summary

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

comparer, comparisonCardinality, doneWarnings, runtimeCheckNeeded, singletonOperator

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

operator

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

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

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
Expression	copy(RebindingMap rebindings)	Copy an expression.
boolean	effectiveBooleanValue(XPathContext context)	Evaluate the expression in a boolean context
Elaborator	getElaborator()	Make an elaborator for this expression
protected GeneralComparison	getInverseComparison()
Expression	optimize(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType)	Optimize the expression
protected String	tag()	Get the element name used to identify this expression in exported expression format

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

compare, computeCardinality, computeHashCode, convertsUntypedToOther, equals, evaluateItem, explainExtraAttributes, getAtomicComparer, getComparisonCardinality, getCorrespondingSingletonOperator, getExpressionName, getIntrinsicDependencies, getItemType, getNamespaceResolver, getSingletonOperator, getStaticUType, getStreamerName, getStringCollator, needsRuntimeCheck, setAtomicComparer, setComparisonCardinality, setNeedsRuntimeCheck, typeCheck

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

computeSpecialProperties, displayOperator, export, getImplementationMethod, getLhs, getLhsExpression, getOperandRole, getOperator, getRhs, getRhsExpression, isAssociative, isCommutative, isInverse, operands, setFlattened, setLhsExpression, setRhsExpression, toShortString, toString

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

addToPathMap, adoptChildExpression, allowExtractingCommonSubexpressions, checkedOperands, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, dispatchTailCall, dynamicError, evaluateAsString, explain, getCardinality, getConfiguration, getCost, getDependencies, getEvaluationMethod, getExtraProperty, getIntegerBounds, getLocalRetainedStaticContext, getLocation, getNetCost, getObjectName, getPackageData, getParentExpression, getProperties, getProperty, getRetainedStaticContext, getScopingExpression, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStaticType, getTracingTag, hasCompatibleStaticContext, hashCode, hasSpecialProperty, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isEqual, isIdentical, isInstruction, isLiftable, isMultiThreaded, isStaticPropertiesKnown, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterate, makeElaborator, markTailFunctionCalls, operandList, operandSparseList, optimizeChildren, prepareForStreaming, process, resetLocalStaticProperties, restoreParentPointers, setEvaluationMethod, setExtraProperty, setFiltered, setLocation, setParentExpression, setRetainedStaticContext, setRetainedStaticContextLocally, setRetainedStaticContextThoroughly, setStaticProperty, simplify, simplifyChildren, staticTypeCheck, supportsLazyEvaluation, suppressValidation, toPattern, typeCheckChildren, typeError, unordered, verifyParentPointers, withLocation

Methods inherited from class java.lang.Object

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

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

getLhs, getLhsExpression, getRhs, getRhsExpression

Methods inherited from interface net.sf.saxon.trace.Traceable

gatherProperties

Constructor Details

GeneralEqualityEE

public GeneralEqualityEE(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 Details

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(RebindingMap rebindings)

Description copied from class: Expression

Copy an expression. This makes a deep copy.

Specified by:

copy in class Expression

Parameters:

rebindings - a mutable list of (old binding, new binding) pairs that is used to update the bindings held in any local variable references that are copied.

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

tag

protected String tag()

Description copied from class: GeneralComparison

Get the element name used to identify this expression in exported expression format

Overrides:

tag in class GeneralComparison

Returns:

the element name used to identify this expression

getElaborator

public Elaborator getElaborator()

Description copied from class: GeneralComparison

Make an elaborator for this expression

Overrides:

getElaborator in class GeneralComparison

Returns:

a suitable elaborator