org.datanucleus.query.evaluator
Class AbstractExpressionEvaluator

java.lang.Object
  org.datanucleus.query.evaluator.AbstractExpressionEvaluator

All Implemented Interfaces:

ExpressionEvaluator

Direct Known Subclasses:

InMemoryExpressionEvaluator

public class AbstractExpressionEvaluator
extends java.lang.Object
implements ExpressionEvaluator

Abstract evaluator for an expression. Provides a stack-like process, working its way through the expression tree. Provides methods processXXX that should be implemented by the subclass where it supports the particular operator or expression.

Constructor Summary

AbstractExpressionEvaluator()

Method Summary

protected java.lang.Object	compileAdditiveMultiplicativeExpression(Expression expr)
protected java.lang.Object	compileOrAndExpression(Expression expr) This method deals with the OR/AND conditions.
protected java.lang.Object	compilePrimaryExpression(Expression expr)
protected java.lang.Object	compileRelationalExpression(Expression expr) Method to handle a relational expression comparing two expressions and returning a BooleanExpression.
protected java.lang.Object	compileUnaryExpression(Expression expr)
java.lang.Object	evaluate(Expression expr) Method to "evaluate" the expression.
protected java.lang.Object	processAddExpression(Expression expr) Method to process the supplied ADD expression.
protected java.lang.Object	processAndExpression(Expression expr) Method to process the supplied AND expression.
protected java.lang.Object	processCaseExpression(CaseExpression expr) Method to process the supplied case expression.
protected java.lang.Object	processCastExpression(Expression expr) Method to process the supplied cast expression.
protected java.lang.Object	processComExpression(Expression expr) Method to process the supplied COM expression.
protected java.lang.Object	processCreatorExpression(CreatorExpression expr) Method to process the supplied creator expression.
protected java.lang.Object	processDistinctExpression(Expression expr) Method to process the supplied DISTINCT expression.
protected java.lang.Object	processDivExpression(Expression expr) Method to process the supplied DIV expression.
protected java.lang.Object	processEqExpression(Expression expr) Method to process the supplied EQ expression.
protected java.lang.Object	processGteqExpression(Expression expr) Method to process the supplied GTEQ expression.
protected java.lang.Object	processGtExpression(Expression expr) Method to process the supplied GT expression.
protected java.lang.Object	processInExpression(Expression expr) Method to process the supplied IN expression.
protected java.lang.Object	processInvokeExpression(InvokeExpression expr) Method to process the supplied invoke expression.
protected java.lang.Object	processIsExpression(Expression expr) Method to process the supplied IS (instanceof) expression.
protected java.lang.Object	processIsnotExpression(Expression expr) Method to process the supplied ISNOT (!instanceof) expression.
protected java.lang.Object	processLikeExpression(Expression expr) Method to process the supplied LIKE expression.
protected java.lang.Object	processLiteral(Literal expr) Method to process the supplied invoke expression.
protected java.lang.Object	processLteqExpression(Expression expr) Method to process the supplied LTEQ expression.
protected java.lang.Object	processLtExpression(Expression expr) Method to process the supplied LT expression.
protected java.lang.Object	processModExpression(Expression expr) Method to process the supplied MOD expression.
protected java.lang.Object	processMulExpression(Expression expr) Method to process the supplied MUL expression.
protected java.lang.Object	processNegExpression(Expression expr) Method to process the supplied NEG expression.
protected java.lang.Object	processNoteqExpression(Expression expr) Method to process the supplied NOTEQ expression.
protected java.lang.Object	processNotExpression(Expression expr) Method to process the supplied NOT expression.
protected java.lang.Object	processNotInExpression(Expression expr) Method to process the supplied NOT IN expression.
protected java.lang.Object	processOrExpression(Expression expr) Method to process the supplied OR expression.
protected java.lang.Object	processParameterExpression(ParameterExpression expr) Method to process the supplied parameter expression.
protected java.lang.Object	processPrimaryExpression(PrimaryExpression expr) Method to process the supplied primary expression.
protected java.lang.Object	processSubExpression(Expression expr) Method to process the supplied SUB expression.
protected java.lang.Object	processSubqueryExpression(SubqueryExpression expr) Method to process the supplied subquery expression.
protected java.lang.Object	processVariableExpression(VariableExpression expr) Method to process the supplied variable expression.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractExpressionEvaluator

public AbstractExpressionEvaluator()

Method Detail

evaluate

public java.lang.Object evaluate(Expression expr)

Method to "evaluate" the expression.

Specified by:

evaluate in interface ExpressionEvaluator

Parameters:

expr - The expression

Returns:

The evaluated expression

compileOrAndExpression

protected java.lang.Object compileOrAndExpression(Expression expr)

This method deals with the OR/AND conditions. A condition specifies a combination of one or more expressions and logical (Boolean) operators and returns a value of TRUE, FALSE, or unknown

compileRelationalExpression

protected java.lang.Object compileRelationalExpression(Expression expr)

Method to handle a relational expression comparing two expressions and returning a BooleanExpression.

Parameters:

expr - The (relational) expression

Returns:

The processed expression

compileAdditiveMultiplicativeExpression

protected java.lang.Object compileAdditiveMultiplicativeExpression(Expression expr)

compileUnaryExpression

protected java.lang.Object compileUnaryExpression(Expression expr)

compilePrimaryExpression

protected java.lang.Object compilePrimaryExpression(Expression expr)

processOrExpression

protected java.lang.Object processOrExpression(Expression expr)

Method to process the supplied OR expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processAndExpression

protected java.lang.Object processAndExpression(Expression expr)

Method to process the supplied AND expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processEqExpression

protected java.lang.Object processEqExpression(Expression expr)

Method to process the supplied EQ expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processNoteqExpression

protected java.lang.Object processNoteqExpression(Expression expr)

Method to process the supplied NOTEQ expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processLikeExpression

protected java.lang.Object processLikeExpression(Expression expr)

Method to process the supplied LIKE expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processGtExpression

protected java.lang.Object processGtExpression(Expression expr)

Method to process the supplied GT expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processLtExpression

protected java.lang.Object processLtExpression(Expression expr)

Method to process the supplied LT expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processGteqExpression

protected java.lang.Object processGteqExpression(Expression expr)

Method to process the supplied GTEQ expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processLteqExpression

protected java.lang.Object processLteqExpression(Expression expr)

Method to process the supplied LTEQ expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processIsExpression

protected java.lang.Object processIsExpression(Expression expr)

Method to process the supplied IS (instanceof) expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processIsnotExpression

protected java.lang.Object processIsnotExpression(Expression expr)

Method to process the supplied ISNOT (!instanceof) expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processInExpression

protected java.lang.Object processInExpression(Expression expr)

Method to process the supplied IN expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processNotInExpression

protected java.lang.Object processNotInExpression(Expression expr)

Method to process the supplied NOT IN expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processAddExpression

protected java.lang.Object processAddExpression(Expression expr)

Method to process the supplied ADD expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processSubExpression

protected java.lang.Object processSubExpression(Expression expr)

Method to process the supplied SUB expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processMulExpression

protected java.lang.Object processMulExpression(Expression expr)

Method to process the supplied MUL expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processDivExpression

protected java.lang.Object processDivExpression(Expression expr)

Method to process the supplied DIV expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processModExpression

protected java.lang.Object processModExpression(Expression expr)

Method to process the supplied MOD expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processNegExpression

protected java.lang.Object processNegExpression(Expression expr)

Method to process the supplied NEG expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processComExpression

protected java.lang.Object processComExpression(Expression expr)

Method to process the supplied COM expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processNotExpression

protected java.lang.Object processNotExpression(Expression expr)

Method to process the supplied NOT expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processDistinctExpression

protected java.lang.Object processDistinctExpression(Expression expr)

Method to process the supplied DISTINCT expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processCreatorExpression

protected java.lang.Object processCreatorExpression(CreatorExpression expr)

Method to process the supplied creator expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processPrimaryExpression

protected java.lang.Object processPrimaryExpression(PrimaryExpression expr)

Method to process the supplied primary expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processParameterExpression

protected java.lang.Object processParameterExpression(ParameterExpression expr)

Method to process the supplied parameter expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processVariableExpression

protected java.lang.Object processVariableExpression(VariableExpression expr)

Method to process the supplied variable expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processSubqueryExpression

protected java.lang.Object processSubqueryExpression(SubqueryExpression expr)

Method to process the supplied subquery expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processInvokeExpression

protected java.lang.Object processInvokeExpression(InvokeExpression expr)

Method to process the supplied invoke expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processCastExpression

protected java.lang.Object processCastExpression(Expression expr)

Method to process the supplied cast expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processCaseExpression

protected java.lang.Object processCaseExpression(CaseExpression expr)

Method to process the supplied case expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result

processLiteral

protected java.lang.Object processLiteral(Literal expr)

Method to process the supplied invoke expression. To be implemented by subclasses.

Parameters:

expr - The expression

Returns:

The result