Package org.codehaus.groovy.ast.expr

Class SwitchExpression

java.lang.Object

org.codehaus.groovy.ast.ASTNode

org.codehaus.groovy.ast.AnnotatedNode

org.codehaus.groovy.ast.expr.Expression

org.codehaus.groovy.ast.expr.SwitchExpression

All Implemented Interfaces:

GroovydocHolder<AnnotatedNode>, NodeMetaDataHandler

public class SwitchExpression
extends Expression

Represents a switch used as an expression, as specified by JEP 361 (Switch Expressions). The selector is evaluated once and matched against the CaseStatement list using Groovy's isCase semantics (or a tableswitch / lookupswitch when the compiler can prove that is equivalent). Each completing arm yields a value via YieldStatement; the expression's result is that value.

Arms stay as CaseStatements, the same way a ClosureExpression holds a statement body: the case label is an expression, the arm is a statement. transformExpression(org.codehaus.groovy.ast.expr.ExpressionTransformer) rewrites the selector and case labels only and shares the arm statements.

Since:

6.0.0

See Also:

• SwitchStatement
• YieldStatement
• CaseStatement

Field Summary

Fields inherited from class org.codehaus.groovy.ast.expr.Expression

EMPTY_ARRAY

Fields inherited from interface groovy.lang.groovydoc.GroovydocHolder

DOC_COMMENT

Constructor Summary

Constructors

Constructor	Description
SwitchExpression(Expression expression)	Constructs a switch expression with the given selector.
SwitchExpression(Expression expression, List<CaseStatement> caseStatements, Statement defaultStatement)	Constructs a switch expression with the given selector, case arms, and default arm.
SwitchExpression(Expression expression, Statement defaultStatement)	Constructs a switch expression with the given selector and default arm.

Method Summary

Modifier and Type	Method	Description
void	addCase(CaseStatement caseStatement)	Adds a case arm to this switch expression.
List<CaseStatement>	getCaseStatements()	Returns the case arms of this switch expression.
Statement	getDefaultStatement()	Returns the arm executed when no case matches.
Expression	getExpression()	Returns the selector expression matched against case values.
String	getText()	Returns a human-readable text representation of this AST node.
void	setDefaultStatement(Statement defaultStatement)	Sets the arm executed when no case matches.
void	setExpression(Expression expression)	Sets the selector expression matched against case values.
String	toString()
Expression	transformExpression(ExpressionTransformer transformer)	Returns a copy whose selector and case labels have been rewritten.
void	visit(GroovyCodeVisitor visitor)	Accepts a code visitor for AST traversal and transformation.

Methods inherited from class org.codehaus.groovy.ast.expr.Expression

getType, setType, transformExpressions, transformExpressions

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

addAnnotation, addAnnotation, addAnnotations, getAnnotations, getAnnotations, getDeclaringClass, getGroovydoc, getInstance, hasNoRealSourcePosition, isSynthetic, setDeclaringClass, setHasNoRealSourcePosition, setSynthetic

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

copyNodeMetaData, getColumnNumber, getLastColumnNumber, getLastLineNumber, getLineNumber, getMetaDataMap, setColumnNumber, setLastColumnNumber, setLastLineNumber, setLineNumber, setMetaDataMap, setSourcePosition

Methods inherited from class java.lang.Object

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

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

copyNodeMetaData, getNodeMetaData, getNodeMetaData, getNodeMetaData, newMetaDataMap, putNodeMetaData, removeNodeMetaData, setNodeMetaData

Constructor Details

SwitchExpression

public SwitchExpression(Expression expression)

Constructs a switch expression with the given selector. The default statement is initialized to EmptyStatement.INSTANCE.

Parameters:

expression - the selector expression

SwitchExpression

public SwitchExpression(Expression expression,
 Statement defaultStatement)

Constructs a switch expression with the given selector and default arm.

Parameters:

expression - the selector expression

defaultStatement - the arm executed when no case matches; may be EmptyStatement.INSTANCE

SwitchExpression

public SwitchExpression(Expression expression,
 List<CaseStatement> caseStatements,
 Statement defaultStatement)

Constructs a switch expression with the given selector, case arms, and default arm.

Parameters:

expression - the selector expression

caseStatements - the case arms

defaultStatement - the arm executed when no case matches

Method Details

getExpression

public Expression getExpression()

Returns the selector expression matched against case values.

Returns:

the selector Expression

setExpression

public void setExpression(Expression expression)

Sets the selector expression matched against case values.

Parameters:

expression - the selector Expression

getCaseStatements

public List<CaseStatement> getCaseStatements()

Returns the case arms of this switch expression.

Returns:

a list of CaseStatement objects; never null

getDefaultStatement

public Statement getDefaultStatement()

Returns the arm executed when no case matches.

Returns:

the default Statement, or EmptyStatement.INSTANCE if not set

setDefaultStatement

public void setDefaultStatement(Statement defaultStatement)

Sets the arm executed when no case matches.

Parameters:

defaultStatement - the default Statement

addCase

public void addCase(CaseStatement caseStatement)

Adds a case arm to this switch expression.

Parameters:

caseStatement - the CaseStatement to add

getText

public String getText()

Description copied from class: ASTNode

Returns a human-readable text representation of this AST node. Used for debugging and error messages. Default implementation returns a message indicating the representation is not yet implemented for this node type.

Overrides:

getText in class ASTNode

Returns:

text representation of this node, or placeholder for unimplemented types

toString

public String toString()

Overrides:

toString in class Object

transformExpression

public Expression transformExpression(ExpressionTransformer transformer)

Returns a copy whose selector and case labels have been rewritten. Arm statements are shared: an ExpressionTransformer does not walk statements.

Specified by:

transformExpression in class Expression

Parameters:

transformer - the ExpressionTransformer to apply

Returns:

a transformed copy of this expression (or this expression itself if no changes are needed)

visit

public void visit(GroovyCodeVisitor visitor)

Description copied from class: ASTNode

Accepts a code visitor for AST traversal and transformation. Subclasses must implement this method to support visitor pattern-based processing. The visitor pattern enables decoupling of AST structure from processing logic.

Overrides:

visit in class ASTNode

Parameters:

visitor - the GroovyCodeVisitor to process this node