Package org.codehaus.groovy.ast.expr

# Class EmptyExpression

java.lang.Object
org.codehaus.groovy.ast.ASTNode
org.codehaus.groovy.ast.AnnotatedNode
org.codehaus.groovy.ast.expr.Expression
org.codehaus.groovy.ast.expr.EmptyExpression

All Implemented Interfaces:
  `GroovydocHolder<AnnotatedNode>`, `NodeMetaDataHandler`

public class EmptyExpression extends Expression
Placeholder for an empty expression. Empty expressions are used in closures lists like (;). During class generation empty expressions should be ignored or replaced with a null value.

See Also:
  - `EmptyStatement`

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final EmptyExpression`
  `INSTANCE`
  Immutable singleton that is recommended for use when source range or any other occurrence-specific metadata is not needed.

  ### 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
  `EmptyExpression()`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `Expression`
  `transformExpression(ExpressionTransformer transformer)`
  Transforms this expression and any nested expressions according to the provided transformer.
  `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, getText, setColumnNumber, setLastColumnNumber, setLastLineNumber, setLineNumber, setMetaDataMap, setSourcePosition`

  ### 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.NodeMetaDataHandler

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

- ## Field Details

  - ### INSTANCE

    public static final EmptyExpression INSTANCE
    Immutable singleton that is recommended for use when source range or any other occurrence-specific metadata is not needed.

- ## Constructor Details

  - ### EmptyExpression

    public EmptyExpression()
    See Also:
      - `INSTANCE`

- ## Method Details

  - ### transformExpression

    public Expression transformExpression(ExpressionTransformer transformer)
    Description copied from class: `Expression`
    Transforms this expression and any nested expressions according to the provided transformer. This method is called during AST transformation phases and must recursively transform any nested expressions to support full AST tree transformation.
    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