Package: org.codehaus.groovy.ast.expr

## [Java] Interface ExpressionTransformer

-     @FunctionalInterface
      public interface ExpressionTransformer

  Functional interface for transforming Expression nodes during AST traversal and manipulation.

  This transformer interface enables expression-level transformations in AST processing. Implementations typically take an input expression and return a (possibly modified) expression. This can be used for:

  - Code generation and transformation passes
  - Expression normalization or optimization
  - Type-driven transformation in static type checking
  - Custom DSL implementation and metaprogramming

  Transformers may return:

  - The same expression instance unchanged
  - A new expression of the same type with modified properties
  - A completely different expression type
  - Null if the expression should be removed (usage-dependent)

  This is a functional interface and can be implemented as a lambda expression.

  See Also:
    for abstract transformer base class
    for visitor using transformers

- - ### Methods Summary

    Methods
    Type Params | Return Type | Name and description
    --- | --- | ---
    `` | `public Expression` | `transform(Expression expression)` Transforms the given expression.

- - ### Method Detail

    - #### public Expression transform(Expression expression)

      Transforms the given expression.

      Parameters:
        `expression` - the expression to transform, may be null
      Returns:
        the transformed expression, may be the same instance, a new instance, or null