org.cumulus4j.store.query.eval
Class ComparisonExpressionEvaluator

java.lang.Object
  org.cumulus4j.store.query.eval.AbstractExpressionEvaluator<DyadicExpression>
      org.cumulus4j.store.query.eval.ComparisonExpressionEvaluator

public class ComparisonExpressionEvaluator
extends AbstractExpressionEvaluator<DyadicExpression>

Evaluator handling the comparisons ==, <, <=, >, >=.

Author:

Marco หงุ่ยตระกูล-Schulze - marco at nightlabs dot de

Constructor Summary

ComparisonExpressionEvaluator(QueryEvaluator queryEvaluator, AbstractExpressionEvaluator<?> parent, DyadicExpression expression)

Method Summary

protected Set<Long>	_queryResultDataEntryIDs(ResultDescriptor resultDescriptor) Execute a query for the given resultDescriptor.
protected Object	getLeftCompareToArgument()
protected Object	getRightCompareToArgument()

Methods inherited from class org.cumulus4j.store.query.eval.AbstractExpressionEvaluator

_getResultSymbols, _queryResultObjects, getExpression, getFieldType, getLeft, getParent, getQueryEvaluator, getResultSymbols, getRight, queryResultDataEntryIDs, queryResultObjects, setLeft, setRight

Methods inherited from class java.lang.Object

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

Constructor Detail

ComparisonExpressionEvaluator

public ComparisonExpressionEvaluator(QueryEvaluator queryEvaluator,
                                     AbstractExpressionEvaluator<?> parent,
                                     DyadicExpression expression)

Method Detail

_queryResultDataEntryIDs

protected Set<Long> _queryResultDataEntryIDs(ResultDescriptor resultDescriptor)

Description copied from class: AbstractExpressionEvaluator

Execute a query for the given resultDescriptor. This method should contain the concrete logic for AbstractExpressionEvaluator.queryResultDataEntryIDs(ResultDescriptor) and must be implemented by subclasses.

Specified by:

_queryResultDataEntryIDs in class AbstractExpressionEvaluator<DyadicExpression>

Parameters:

resultDescriptor - the descriptor specifying what candidates (usually "this" or a variable) the caller is interested in as well as modifiers (e.g. negation) affecting the query.

Returns:

those dataEntryIDs that match the query criteria for the specified resultSymbol or null, if the symbol is not supported (this should be consistent with the implementation of AbstractExpressionEvaluator._getResultSymbols()).

See Also:

AbstractExpressionEvaluator.queryResultDataEntryIDs(ResultDescriptor)

getLeftCompareToArgument

protected Object getLeftCompareToArgument()

getRightCompareToArgument

protected Object getRightCompareToArgument()