Package com.tangosol.coherence.dslquery.operator

Class ComparisonOperator

java.lang.Object

com.tangosol.coherence.dslquery.operator.BaseOperator<ComparisonFilter>

com.tangosol.coherence.dslquery.operator.ComparisonOperator

Direct Known Subclasses:

EqualsOperator, GreaterEqualsOperator, GreaterOperator, LessEqualsOperator, LessOperator, NotEqualsOperator

public abstract class ComparisonOperator
extends BaseOperator<ComparisonFilter>

A base class for comparison operators, which are operators that are used in conditional clauses such as equals, greater than, less than, etc.

Since:

Coherence 12.2.1

Author:

jk 2013.12.03

Field Summary

Fields inherited from class com.tangosol.coherence.dslquery.operator.BaseOperator

f_asAlias, f_fConditional, f_sSymbol

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	ComparisonOperator(String sSymbol, String... asAliases)	Construct a comparison operator with the given symbol and aliases.

Method Summary

Modifier and Type	Method	Description
abstract BaseOperator<ComparisonFilter>	flip()	Return the operator to use if this operation needs to be flipped due to the CohQL statement having the literal on the left hand side.
ComparisonFilter	makeFilter(Term termLeft, Term termRight, TermWalker walker)	Create a Filter for this BaseOperator using the specified left and right Terms.

Methods inherited from class com.tangosol.coherence.dslquery.operator.BaseOperator

addAliases, addToTokenTable, getAliases, getSymbol, isConditional, makeExtractor, makeExtractor, makeFilter, toString, unmodifiableSet

Methods inherited from class java.lang.Object

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

Constructor Details

ComparisonOperator

protected ComparisonOperator(String sSymbol,
 String... asAliases)

Construct a comparison operator with the given symbol and aliases.

Parameters:

sSymbol - the symbol for this operator

asAliases - any aliases for this operator

Method Details

makeFilter

public ComparisonFilter makeFilter(Term termLeft,
 Term termRight,
 TermWalker walker)

Description copied from class: BaseOperator

Create a Filter for this BaseOperator using the specified left and right Terms.

Note: This method should be thread safe as operators are stored in a static map so may be called by multiple threads.

Overrides:

makeFilter in class BaseOperator<ComparisonFilter>

Parameters:

termLeft - the left term to use to build a Filter

termRight - the right term to use to build a Filter

walker - the TermWalker to use to process the left and right terms

Returns:

a Filter representing this operation.

flip

public abstract BaseOperator<ComparisonFilter> flip()

Return the operator to use if this operation needs to be flipped due to the CohQL statement having the literal on the left hand side. For example if the statement was "2 == foo" this would need to be flipped to put the literal on the right so giving the statement "foo == 2" and the flipped operator is still ==. But for another example such as "2 >= foo" flipping this give the statement "foo <= 2" so the operator has changed from >= to <=

Returns:

the operator to use if this operation needs to be flipped due to the CohQL statement having the literal on the left hand side.