com.saxonica.extra
Class GeneralComparisonSA

java.lang.Object
  net.sf.saxon.expr.Expression
      net.sf.saxon.expr.BinaryExpression
          net.sf.saxon.expr.GeneralComparison
              com.saxonica.extra.GeneralComparisonSA

All Implemented Interfaces:

Serializable, SourceLocator, ComparisonExpression, Container, EvaluableItem, SequenceIterable, InstructionInfoProvider

public class GeneralComparisonSA
extends GeneralComparison

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

See Also:

Serialized Form

Field Summary

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

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD

Constructor Summary

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

Method Summary

boolean	effectiveBooleanValue(XPathContext context) Evaluate the expression in a boolean context
Expression	optimize(Optimizer opt, StaticContext env, ItemType contextItemType) Optimize the expression

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

computeCardinality, convertsUntypedToOther, evaluateItem, getAtomicComparer, getItemType, getSingletonOperator, typeCheck

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

computeSpecialProperties, display, equals, getOperands, getOperator, hashCode, iterateSubExpressions, promote, replaceSubExpression, simplify

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

adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, evaluateAsString, getCardinality, getColumnNumber, getContainingProcedure, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, iterate, markTailFunctionCalls, process, resetStaticProperties, setLocationId, setParentExpression, setParentExpression, suppressValidation

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, toString, wait, wait, wait

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

getOperands

Constructor Detail

GeneralComparisonSA

public GeneralComparisonSA(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(Optimizer opt,
                           StaticContext env,
                           ItemType contextItemType)
                    throws XPathException

Description copied from class: GeneralComparison

Optimize the expression

Overrides:

optimize in class GeneralComparison

Parameters:

opt - the optimizer in use. This provides access to supporting functions; it also allows different optimization strategies to be used in different circumstances.

env - the static context of the expression

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:

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

XPathException

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