Package org.apache.calcite.linq4j.tree

Class OptimizeShuttle

java.lang.Object

org.apache.calcite.linq4j.tree.Shuttle

org.apache.calcite.linq4j.tree.OptimizeShuttle

public class OptimizeShuttle
extends Shuttle

Shuttle that optimizes expressions.

The optimizations are essential, not mere tweaks. Without optimization, expressions such as false == null will be left in, which are invalid to Janino (because it does not automatically box primitives).

Field Summary

Fields

Modifier and Type	Field	Description
static final MemberExpression	BOXED_FALSE_EXPR
static final MemberExpression	BOXED_TRUE_EXPR
static final Statement	EMPTY_STATEMENT
static final ConstantExpression	FALSE_EXPR
static final ConstantExpression	TRUE_EXPR

Constructor Summary

Constructors

Constructor	Description
OptimizeShuttle()

Method Summary

Modifier and Type	Method	Description
protected boolean	isKnownNotNull(Expression expression)	Returns whether an expression always returns a non-null result.
Expression	visit(BinaryExpression binary, Expression expression0, Expression expression1)
Statement	visit(ConditionalStatement conditionalStatement, List<Node> list)
Expression	visit(MethodCallExpression methodCallExpression, @Nullable Expression targetExpression, List<Expression> expressions)
Expression	visit(TernaryExpression ternary, Expression expression0, Expression expression1, Expression expression2)
Expression	visit(UnaryExpression unaryExpression, Expression expression)

Methods inherited from class org.apache.calcite.linq4j.tree.Shuttle

preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, preVisit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit

Methods inherited from class java.lang.Object

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

Field Details

FALSE_EXPR

public static final ConstantExpression FALSE_EXPR

TRUE_EXPR

public static final ConstantExpression TRUE_EXPR

BOXED_FALSE_EXPR

public static final MemberExpression BOXED_FALSE_EXPR

BOXED_TRUE_EXPR

public static final MemberExpression BOXED_TRUE_EXPR

EMPTY_STATEMENT

public static final Statement EMPTY_STATEMENT

Constructor Details

OptimizeShuttle

public OptimizeShuttle()

Method Details

visit

public Expression visit(TernaryExpression ternary,
 Expression expression0,
 Expression expression1,
 Expression expression2)

Overrides:

visit in class Shuttle

visit

public Expression visit(BinaryExpression binary,
 Expression expression0,
 Expression expression1)

Overrides:

visit in class Shuttle

visit

public Expression visit(UnaryExpression unaryExpression,
 Expression expression)

Overrides:

visit in class Shuttle

visit

public Statement visit(ConditionalStatement conditionalStatement,
 List<Node> list)

Overrides:

visit in class Shuttle

visit

public Expression visit(MethodCallExpression methodCallExpression,
 @Nullable Expression targetExpression,
 List<Expression> expressions)

Overrides:

visit in class Shuttle

isKnownNotNull

protected boolean isKnownNotNull(Expression expression)

Returns whether an expression always returns a non-null result. For instance, primitive types cannot contain null values.

Parameters:

expression - expression to test

Returns:

true when the expression is known to be not-null