Direct Known Satisfying Interfaces: ConstrainedAnnotation<Value,Values,ProgramElement>

The supertype of all annotation classes.

Annotation classes

An annotation class must satisfy Annotation, OptionalAnnotation, or SequencedAnnotation and must be annotated final annotation. For example:

"An annotation class."
final annotation class Example(shared String description) 
      satisfies Annotation {}

Annotation classes which satisfy Annotation directly may be applied to any program element that supports annotations (see Annotated). In practice, annotation classes often satisfy OptionalAnnotation or SequencedAnnotation in order to prevent annotations being applied to inappropriate program elements.

Each initializer parameter of an annotation class must have one of the following types:

  • Integer, Float, Character, or String,
  • an enumerated type whose cases are all anonymous classes, such as Boolean,
  • a subtype of ceylon.language.meta.declaration::Declaration
  • an annotation class,
  • {T*} or [T*] where T is a legal annotation parameter type, or
  • any tuple type whose element types are legal annotation parameter types.

An initializer parameter of an annotation class may be variadic or defaulted.

Annotation constructors

An annotation constructor is simply a top level function, annotated with annotation whose return type is an annotation class type. For example:

"An annotation constructor."
annotation Example example(String description="") 
    => Example(description);

Each parameter of an annotation constructor must have one of the following types:

  • Integer, Float, Character, or String,
  • an enumerated type whose cases are all anonymous classes, such as Boolean,
  • a subtype of ceylon.language.meta.declaration::Declaration,
  • an annotation type,
  • {T*} or [T*] where T is a legal annotation constructor parameter type, or
  • any tuple type whose element types are legal annotation constructor parameter types.

A parameter of an annotation constructor may be variadic or defaulted.

The constructor must simply instantiate and return the annotation class, and there are strict rules about the arguments to the instantiation.

An annotation class can have multiple annotation constructors.

Inherited Attributes
Attributes inherited from: Object
Inherited Methods
Methods inherited from: Object