org.exist.xquery
Class ValueComparison

java.lang.Object
  org.exist.xquery.AbstractExpression
      org.exist.xquery.PathExpr
          org.exist.xquery.BinaryOp
              org.exist.xquery.GeneralComparison
                  org.exist.xquery.ValueComparison

All Implemented Interfaces:

CompiledXQuery, Expression, IndexUseReporter, Optimizable, RewritableExpression, org.xmldb.api.base.CompiledExpression

public class ValueComparison
extends GeneralComparison

Nested Class Summary

Nested classes/interfaces inherited from class org.exist.xquery.GeneralComparison

GeneralComparison.IndexFlags

Field Summary

Fields inherited from class org.exist.xquery.GeneralComparison

cached, collationArg, invalidNodeEvaluation, inWhereClause, optimizeChild, optimizeSelf, relation, rightOpDeps, truncation

Fields inherited from class org.exist.xquery.PathExpr

inPredicate, keepVirtual, LOG, parent, staticContext, steps

Fields inherited from class org.exist.xquery.AbstractExpression

column, context, contextDocSet, contextId, line, unordered

Fields inherited from interface org.exist.xquery.Expression

DOT_TEST, EXPRESSION_ID_INVALID, IGNORE_CONTEXT, IN_NODE_CONSTRUCTOR, IN_PREDICATE, IN_UPDATE, IN_WHERE_CLAUSE, NEED_INDEX_INFO, NO_CONTEXT_ID, NON_STREAMABLE, POSITIONAL_PREDICATE, SINGLE_STEP_EXECUTION, UNORDERED, USE_TREE_TRAVERSAL

Constructor Summary

ValueComparison(XQueryContext context, Expression left, Expression right, int relation)

ValueComparison(XQueryContext context, int relation)

Method Summary

static boolean	compareAtomic(java.text.Collator collator, AtomicValue lv, AtomicValue rv, int truncation, int relation) Cast the atomic operands into a comparable type and compare them.
void	dump(ExpressionDumper dumper) Write a diagnostic dump of the expression to the passed ExpressionDumper.
protected Sequence	genericCompare(Sequence contextSequence, Item contextItem) Generic, slow implementation.
protected Sequence	nodeSetCompare(NodeSet nodes, Sequence contextSequence) Optimized implementation, which can be applied if the left operand returns a node set.
java.lang.String	toString()

Methods inherited from class org.exist.xquery.GeneralComparison

accept, analyze, canOptimize, checkForQNameIndex, eval, genericCompare, getCollator, getDependencies, getOptimizeAxis, getRelation, hasUsedIndex, optimizeOnChild, optimizeOnSelf, preSelect, quickNodeSetCompare, resetState, returnsType, setCollation, simplifyOperands, switchOperands

Methods inherited from class org.exist.xquery.BinaryOp

getLeft, getRight, setContextDocSet, setLeft, setRight, simplify

Methods inherited from class org.exist.xquery.PathExpr

add, add, addPath, addPredicate, allowMixNodesInReturn, dump, getCardinality, getColumn, getContext, getDocumentSet, getExpression, getLastExpression, getLength, getLine, getLiteralValue, getParent, getPrimaryAxis, getSubExpression, getSubExpressionCount, isValid, replaceExpression, replaceLastExpression, reset, setContext, setPrimaryAxis, setUseStaticContext

Methods inherited from class org.exist.xquery.AbstractExpression

eval, getContextDocSet, getContextId, getExpressionId, getSource, match, needsReset, setASTNode, setContextId, setLocation

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.exist.xquery.Expression

allowMixNodesInReturn, eval, getCardinality, getColumn, getContext, getContextDocSet, getContextId, getExpressionId, getLine, getParent, getPrimaryAxis, getSource, getSubExpression, getSubExpressionCount, match, needsReset, setASTNode, setContextDocSet, setContextId, setLocation, setPrimaryAxis, simplify

Methods inherited from interface org.exist.xquery.CompiledXQuery

eval, getSource

Constructor Detail

ValueComparison

public ValueComparison(XQueryContext context,
                       int relation)

Parameters:

context -

relation -

ValueComparison

public ValueComparison(XQueryContext context,
                       Expression left,
                       Expression right,
                       int relation)

Parameters:

context -

left -

right -

relation -

Method Detail

genericCompare

protected Sequence genericCompare(Sequence contextSequence,
                                  Item contextItem)
                           throws XPathException

Description copied from class: GeneralComparison

Generic, slow implementation. Applied if none of the possible optimizations can be used.

Overrides:

genericCompare in class GeneralComparison

Returns:

The Sequence resulting from the comparison

Throws:

XPathException

nodeSetCompare

protected Sequence nodeSetCompare(NodeSet nodes,
                                  Sequence contextSequence)
                           throws XPathException

Description copied from class: GeneralComparison

Optimized implementation, which can be applied if the left operand returns a node set. In this case, the left expression is executed first. All matching context nodes are then passed to the right expression.

Overrides:

nodeSetCompare in class GeneralComparison

Parameters:

nodes - DOCUMENT ME!

contextSequence - DOCUMENT ME!

Returns:

DOCUMENT ME!

Throws:

XPathException - DOCUMENT ME!

compareAtomic

public static boolean compareAtomic(java.text.Collator collator,
                                    AtomicValue lv,
                                    AtomicValue rv,
                                    int truncation,
                                    int relation)
                             throws XPathException

Cast the atomic operands into a comparable type and compare them.

Throws:

XPathException

dump

public void dump(ExpressionDumper dumper)

Description copied from interface: Expression

Write a diagnostic dump of the expression to the passed ExpressionDumper.

Specified by:

dump in interface Expression

Overrides:

dump in class GeneralComparison

Parameters:

dumper - the expression dumper to write to

toString

public java.lang.String toString()

Overrides:

toString in class GeneralComparison