Package com.tangosol.coherence.dslquery.operator

Class BaseOperator<F extends Filter>

java.lang.Object

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

Direct Known Subclasses:

AdditionOperator, AndOperator, BetweenOperator, ComparisonOperator, ContainsAllOperator, ContainsAnyOperator, ContainsOperator, DivisionOperator, InOperator, LikeOperator, MultiplicationOperator, OrOperator, SubtractionOperator, XorOperator

public abstract class BaseOperator<F extends Filter>
extends Object

A base class for CohQL Operator implementations.

Since:

Coherence 12.2.1

Author:

jk 2013.12.03

Field Summary

Fields

Modifier and Type	Field	Description
protected String[]	f_asAlias	An array of optional aliases for this operator.
protected boolean	f_fConditional	Flag indicating whether this operator can be used as a conditional operator, for example ==, >=, etc, as opposed to a non-conditional operator such as +, -, etc.
protected String	f_sSymbol	The symbol for this operator.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	BaseOperator(String sSymbol, boolean fConditional, String... asAlias)	Create an instance of a BaseOperator with the specified symbol, conditional flag and aliases.

Method Summary

Modifier and Type	Method	Description
protected void	addAliases(TokenTable tokenTable)	Add any aliases of this operator to the specified token table.
abstract void	addToTokenTable(TokenTable tokenTable)	Add this operator to the given TokenTable.
String[]	getAliases()	Return the alternative symbols to use in CohQL that represent this operator.
String	getSymbol()	Return the symbol to use in CohQL that represents this operator.
boolean	isConditional()	Return true if this operator can be used as a conditional operator.
ValueExtractor	makeExtractor(Term termLeft, Term termRight, TermWalker walker)	Create a ValueExtractor for this BaseOperator using the specified left and right Terms.
ValueExtractor	makeExtractor(Object oLeft, Object oRight)	Create a ValueExtractor for this BaseOperator using the specified left and right values.
F	makeFilter(Term termLeft, Term termRight, TermWalker walker)	Create a Filter for this BaseOperator using the specified left and right Terms.
F	makeFilter(Object oLeft, Object oRight)	Create a Filter for this BaseOperator using the specified left and right values.
String	toString()
protected static Set	unmodifiableSet(Object oValue)	Return an immutable Set accounting for the provided object being an array, a Collection or a single item in the returned Set.

Methods inherited from class java.lang.Object

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

Field Detail

f_sSymbol

protected final String f_sSymbol

The symbol for this operator.

f_asAlias

protected final String[] f_asAlias

An array of optional aliases for this operator.

f_fConditional

protected final boolean f_fConditional

Flag indicating whether this operator can be used as a conditional operator, for example ==, >=, etc, as opposed to a non-conditional operator such as +, -, etc.

Constructor Detail

BaseOperator

protected BaseOperator(String sSymbol,
                       boolean fConditional,
                       String... asAlias)

Create an instance of a BaseOperator with the specified symbol, conditional flag and aliases.

Parameters:

sSymbol - the symbol for this operator

fConditional - a flag indicating whether this operator is conditional

asAlias - an optional list of aliases for this operator

Method Detail

getSymbol

public String getSymbol()

Return the symbol to use in CohQL that represents this operator.

Returns:

the symbol to use in CohQL that represents this operator

getAliases

public String[] getAliases()

Return the alternative symbols to use in CohQL that represent this operator.

Returns:

the alternative symbols to use in CohQL that represent this operator

makeFilter

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

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.

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.

makeFilter

public F makeFilter(Object oLeft,
                    Object oRight)

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

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

Parameters:

oLeft - the left value to use to build a Filter

oRight - the right value to use to build a Filter

Returns:

a Filter representing this operation

makeExtractor

public ValueExtractor makeExtractor(Term termLeft,
                                    Term termRight,
                                    TermWalker walker)

Create a ValueExtractor 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.

Parameters:

termLeft - the left term to use to build a ValueExtractor

termRight - the right term to use to build a ValueExtractor

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

Returns:

a ValueExtractor representing this operation

makeExtractor

public ValueExtractor makeExtractor(Object oLeft,
                                    Object oRight)

Create a ValueExtractor for this BaseOperator using the specified left and right values.

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

Parameters:

oLeft - the left value to use to build a ValueExtractor

oRight - the right value to use to build a ValueExtractor

Returns:

a ValueExtractor representing this operation

isConditional

public boolean isConditional()

Return true if this operator can be used as a conditional operator.

Returns:

true if this operator can be used as a conditional operator

addToTokenTable

public abstract void addToTokenTable(TokenTable tokenTable)

Add this operator to the given TokenTable. This typically means adding this operator using its symbol and also adding any aliases.

Parameters:

tokenTable - the TokenTable to add this operator to

toString

public String toString()

Overrides:

toString in class Object

addAliases

protected void addAliases(TokenTable tokenTable)

Add any aliases of this operator to the specified token table.

Parameters:

tokenTable - the token table to add aliases to

unmodifiableSet

protected static Set unmodifiableSet(Object oValue)

Return an immutable Set accounting for the provided object being an array, a Collection or a single item in the returned Set.

Parameters:

oValue - either an object array, a collection or a single item to be returned as a Set

Returns:

a Set contained the provided object