| Class | Description | 
                            | ASTTransformationsContext | Stores state information about global AST transformations applied to a compilation unit. | 
                            | AnnotationConstantsVisitor | Visitor to resolve constants in annotation definitions. | 
                            | ClassNodeResolver | This class is used as a pluggable way to resolve class names. | 
                            | ClassNodeResolver.LookupResult | Helper class to return either a SourceUnit or ClassNode. | 
                            | CompilationUnit | The CompilationUnit collects all compilation data as it is generated by the compiler system. | 
                            | CompilationUnit.ClassgenCallback | A callback interface you can use to "accompany" the classgen()
 code as it traverses the ClassNode tree. | 
                            | CompilationUnit.GroovyClassOperation |  | 
                            | CompilationUnit.PrimaryClassNodeOperation | An callback interface for use in the applyToPrimaryClassNodes loop driver. | 
                            | CompilationUnit.ProgressCallback | A callback interface you can use to get a callback after every
 unit of the compile process. | 
                            | CompilationUnit.SourceUnitOperation | An callback interface for use in the applyToSourceUnits loop driver. | 
                            | CompilerConfiguration | Compilation control flags and coordination stuff. | 
                            | ErrorCollector | A base class for collecting messages and errors during processing. | 
                            | GenericsVisitor | Verify correct usage of generics. | 
                            | InstanceOfVerifier |  | 
                            | Janitor | An agent that can be used to defer cleanup operations to
 a later time. | 
                            | LabelVerifier | This class checks the handling of labels in the AST | 
                            | OptimizerVisitor | Visitor to produce several optimizations: 
 to replace numbered constants with references to static fieldsremove superfluous references to GroovyObject interface | 
                            | ParserPluginFactory | A factory of parser plugin instances | 
                            | Phases | Compilation phase identifiers. | 
                            | ProcessingUnit | A base class for data structures that can collect messages and errors
 during processing. | 
                            | ResolveVisitor | Visitor to resolve Types and convert VariableExpression to
 ClassExpressions if needed. | 
                            | SourceExtensionHandler | Looks for source file extensions in META-INF/services/org.codehaus.groovy.source.Extensions | 
                            | SourceUnit | Provides an anchor for a single source unit (usually a script file)
 as it passes through the compiler system. | 
                            | StaticImportVisitor | Visitor to resolve constants and method calls from static imports. | 
                            | StaticVerifier | Checks for dynamic variables in static contexts. | 
                            | XStreamUtils |  |