checkers.quals.SubtypeOf Maven / Gradle / Ivy
package checkers.quals;
import java.lang.annotation.*;
/**
* A meta-annotation to specify all the qualifiers that the given qualifier
* is a subtype of. This provides a declarative way to specify the type
* qualifier hierarchy. (Alternatively, the hierarchy can be defined
* procedurally by subclassing {@link checkers.types.QualifierHierarchy} or
* {@link checkers.types.TypeHierarchy}.)
*
*
* Example:
*
@SubtypeOf( { Nullable.class } )
* public @interface NonNull { }
*
*
*
*
* If a qualified type is a subtype of the same type without any qualifier,
* then use Unqualified.class in place of a type qualifier
* class. For example, to express that @Encrypted C
* is a subtype of C (for every class
* C), and likewise for @Interned, write:
*
*
@SubtypeOf(Unqualified.class)
* public @interface Encrypted { }
*
* @SubtypeOf(Unqualified.class)
* public @interface Interned { }
*
*
*
*
* For the top qualifier in the qualifier hierarchy (i.e., the
* qualifier that is a supertype of all other qualifiers in the given
* hierarchy), use an empty set of values:
*
*
@SubtypeOf( { } )
* public @interface Nullable { }
*
* @SubtypeOf( {} )
* public @interface ReadOnly { }
*
*
*
* Together, all the @SubtypeOf meta-annotations fully describe the type
* qualifier hierarchy.
* No @SubtypeOf meta-annotation is needed on (or can be written on) the
* Unqualified pseudo-qualifier, whose position in the hierarchy is
* inferred from the meta-annotations on the explicit qualifiers.
*/
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.ANNOTATION_TYPE)
public @interface SubtypeOf {
/** An array of the supertype qualifiers of the annotated qualifier **/
Class[] value();
}