Package org.codehaus.groovy.classgen

Class FinalVariableAnalyzer

java.lang.Object

org.codehaus.groovy.ast.CodeVisitorSupport

org.codehaus.groovy.ast.ClassCodeVisitorSupport

org.codehaus.groovy.classgen.FinalVariableAnalyzer

All Implemented Interfaces:

GroovyClassVisitor, GroovyCodeVisitor, ErrorCollecting

public class FinalVariableAnalyzer
extends ClassCodeVisitorSupport

Analyzes variable assignments to determine if variables are effectively final, which is required for use in closures and lambda expressions. This visitor tracks variable states through control flow to detect reassignments that would prevent a variable from being considered effectively final.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	FinalVariableAnalyzer.VariableNotFinalCallback	Callback interface notified when effectively final analysis detects a problem.

Constructor Summary

Constructors

Constructor	Description
FinalVariableAnalyzer(SourceUnit sourceUnit)	Creates a new final variable analyzer without a callback.
FinalVariableAnalyzer(SourceUnit sourceUnit, FinalVariableAnalyzer.VariableNotFinalCallback callback)	Creates a new final variable analyzer with a callback for non-final variable detection.

Method Summary

Modifier and Type	Method	Description
protected SourceUnit	getSourceUnit()	Provides access to the SourceUnit for error reporting during visitation.
boolean	isEffectivelyFinal(Variable v)	Determines if a variable is effectively final, meaning it is not reassigned after initialization.
void	visitArgumentlistExpression(ArgumentListExpression ale)	Visits an ArgumentListExpression, treating it as a tuple expression.
void	visitBinaryExpression(BinaryExpression expression)	Visits a BinaryExpression, traversing left and right operand expressions.
void	visitBlockStatement(BlockStatement block)	Visits a BlockStatement, invoking the statement hook before parent traversal.
void	visitClosureExpression(ClosureExpression expression)	Visits a ClosureExpression with annotation processing, traversing parameter annotations before delegating to parent traversal.
void	visitIfElse(IfStatement ifElse)	Visits an IfStatement, invoking the statement hook before parent traversal.
void	visitPostfixExpression(PostfixExpression expression)	Visits a PostfixExpression, traversing the operand expression.
void	visitPrefixExpression(PrefixExpression expression)	Visits a PrefixExpression, traversing the operand expression.
void	visitSwitch(SwitchStatement switchS)	Visits a SwitchStatement, invoking the statement hook before parent traversal.
void	visitTryCatchFinally(TryCatchStatement statement)	Visits a TryCatchStatement, invoking the statement hook before parent traversal.
void	visitVariableExpression(VariableExpression expression)	Visits a VariableExpression.

Methods inherited from class org.codehaus.groovy.ast.ClassCodeVisitorSupport

addError, visitAnnotation, visitAnnotations, visitAnnotations, visitAssertStatement, visitBreakStatement, visitCaseStatement, visitCatchStatement, visitClass, visitClassCodeContainer, visitConstructor, visitConstructorOrMethod, visitContinueStatement, visitDeclarationExpression, visitDoWhileLoop, visitExpressionStatement, visitField, visitForLoop, visitImports, visitMethod, visitObjectInitializerStatements, visitPackage, visitProperty, visitReturnStatement, visitStatement, visitStatementAnnotations, visitSynchronizedStatement, visitThrowStatement, visitWhileLoop

Methods inherited from class org.codehaus.groovy.ast.CodeVisitorSupport

afterSwitchCaseStatementsVisited, afterSwitchConditionExpressionVisited, visitArrayExpression, visitAttributeExpression, visitBitwiseNegationExpression, visitBooleanExpression, visitBytecodeExpression, visitCastExpression, visitClassExpression, visitClosureListExpression, visitConstantExpression, visitConstructorCallExpression, visitEmptyStatement, visitFieldExpression, visitGStringExpression, visitLambdaExpression, visitListExpression, visitMapEntryExpression, visitMapExpression, visitMethodCallExpression, visitMethodPointerExpression, visitMethodReferenceExpression, visitNotExpression, visitPropertyExpression, visitRangeExpression, visitShortTernaryExpression, visitSpreadExpression, visitSpreadMapExpression, visitStaticMethodCallExpression, visitTernaryExpression, visitTupleExpression, visitUnaryMinusExpression, visitUnaryPlusExpression

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.codehaus.groovy.ast.GroovyCodeVisitor

visit, visit, visitEmptyExpression, visitListOfExpressions

Constructor Details

FinalVariableAnalyzer

public FinalVariableAnalyzer(SourceUnit sourceUnit)

Creates a new final variable analyzer without a callback.

Parameters:

sourceUnit - the source unit being analyzed

FinalVariableAnalyzer

public FinalVariableAnalyzer(SourceUnit sourceUnit,
 FinalVariableAnalyzer.VariableNotFinalCallback callback)

Creates a new final variable analyzer with a callback for non-final variable detection.

Parameters:

sourceUnit - the source unit being analyzed

callback - the callback to invoke when a variable is found to not be final, may be null

Method Details

getSourceUnit

protected SourceUnit getSourceUnit()

Provides access to the SourceUnit for error reporting during visitation. Implementations must override this method.

Specified by:

getSourceUnit in class ClassCodeVisitorSupport

Returns:

the source unit for this visitor

isEffectivelyFinal

public boolean isEffectivelyFinal(Variable v)

Determines if a variable is effectively final, meaning it is not reassigned after initialization. Parameters without any state information are considered effectively final by default.

Parameters:

v - the variable to check

Returns:

true if the variable is effectively final, false otherwise

visitBlockStatement

public void visitBlockStatement(BlockStatement block)

Visits a BlockStatement, invoking the statement hook before parent traversal.

Specified by:

visitBlockStatement in interface GroovyCodeVisitor

Overrides:

visitBlockStatement in class ClassCodeVisitorSupport

Parameters:

block - the block statement to visit

See Also:

• CodeVisitorSupport.visitForLoop(ForStatement)
• CodeVisitorSupport.visitWhileLoop(WhileStatement)

visitArgumentlistExpression

public void visitArgumentlistExpression(ArgumentListExpression ale)

Visits an ArgumentListExpression, treating it as a tuple expression.

Specified by:

visitArgumentlistExpression in interface GroovyCodeVisitor

Overrides:

visitArgumentlistExpression in class CodeVisitorSupport

Parameters:

ale - the argument list expression

visitBinaryExpression

public void visitBinaryExpression(BinaryExpression expression)

Visits a BinaryExpression, traversing left and right operand expressions.

Specified by:

visitBinaryExpression in interface GroovyCodeVisitor

Overrides:

visitBinaryExpression in class CodeVisitorSupport

Parameters:

expression - the binary expression

visitClosureExpression

public void visitClosureExpression(ClosureExpression expression)

Visits a ClosureExpression with annotation processing, traversing parameter annotations before delegating to parent traversal.

Specified by:

visitClosureExpression in interface GroovyCodeVisitor

Overrides:

visitClosureExpression in class ClassCodeVisitorSupport

Parameters:

expression - the closure expression to visit

visitPrefixExpression

public void visitPrefixExpression(PrefixExpression expression)

Visits a PrefixExpression, traversing the operand expression.

Specified by:

visitPrefixExpression in interface GroovyCodeVisitor

Overrides:

visitPrefixExpression in class CodeVisitorSupport

Parameters:

expression - the prefix expression

visitPostfixExpression

public void visitPostfixExpression(PostfixExpression expression)

Visits a PostfixExpression, traversing the operand expression.

Specified by:

visitPostfixExpression in interface GroovyCodeVisitor

Overrides:

visitPostfixExpression in class CodeVisitorSupport

Parameters:

expression - the postfix expression

visitVariableExpression

public void visitVariableExpression(VariableExpression expression)

Visits a VariableExpression. No traversal is performed as variable expressions contain no child expressions.

Specified by:

visitVariableExpression in interface GroovyCodeVisitor

Overrides:

visitVariableExpression in class CodeVisitorSupport

Parameters:

expression - the variable expression

visitIfElse

public void visitIfElse(IfStatement ifElse)

Visits an IfStatement, invoking the statement hook before parent traversal.

Specified by:

visitIfElse in interface GroovyCodeVisitor

Overrides:

visitIfElse in class ClassCodeVisitorSupport

Parameters:

ifElse - the if statement to visit

visitSwitch

public void visitSwitch(SwitchStatement switchS)

Visits a SwitchStatement, invoking the statement hook before parent traversal.

Specified by:

visitSwitch in interface GroovyCodeVisitor

Overrides:

visitSwitch in class ClassCodeVisitorSupport

Parameters:

switchS - the switch statement to visit

visitTryCatchFinally

public void visitTryCatchFinally(TryCatchStatement statement)

Visits a TryCatchStatement, invoking the statement hook before parent traversal.

Specified by:

visitTryCatchFinally in interface GroovyCodeVisitor

Overrides:

visitTryCatchFinally in class ClassCodeVisitorSupport

Parameters:

statement - the try-catch statement to visit