| BaseType | Common superinterface for all nodes representing a primitive type. |
| FieldTypeSignature | Common superinterface for nodes that represent a (possibly generic) type. |
| ReturnType | |
| Signature | Common superinterface for generic signatures. |
| Tree | Root of the abstract syntax tree hierarchy for generic signatures |
| TypeArgument | Common supertype for all possible type arguments in the generic signature AST. |
| TypeSignature | Common superinterface for all signatures that represent a type expression. |
| TypeTree | Common supertype for all nodes that represent type expressions in the generic signature AST. |
| ArrayTypeSignature | |
| BooleanSignature | AST that represents the type boolean. |
| BottomSignature | |
| ByteSignature | AST that represents the type byte. |
| CharSignature | AST that represents the type char. |
| ClassSignature | |
| ClassTypeSignature | AST representing class types. |
| DoubleSignature | AST that represents the type double. |
| FloatSignature | AST that represents the type float. |
| FormalTypeParameter | AST that represents a formal type parameter. |
| IntSignature | AST that represents the type int. |
| LongSignature | AST that represents the type long. |
| MethodTypeSignature | |
| ShortSignature | AST that represents the type short. |
| SimpleClassTypeSignature | |
| TypeVariableSignature | |
| VoidDescriptor | AST that represents the pseudo-type void. |
| Wildcard |