    import ceylon.language { AnnotationType = Annotation }
    import ceylon.language.meta.model {
        Class,
        MemberClass,
        AppliedType = Type,
        IncompatibleTypeException,
        TypeApplicationException
    }

    """Class declaration.

       ### Callable classes

       Since Ceylon 1.2 classes are not always directly invokable
       (if the class has constructors, but not a default constructor). Thus
       members of `ClassDeclaration` which depend on the class parameter
       list typically have optional type, but are refined on
       [[ClassWithInitializerDeclaration]] to be non-optional. The exceptions to
       this are [[instantiate]] and [[memberInstantiate]],
       which throw exceptions.

       <a name="toplevel-sample"></a>
       ### Usage sample for toplevel classes

       Because some classes have type parameters, getting a model requires applying type arguments to the
       class declaration with [[classApply]] in order to be able to instantiate that class. For example, here is how you would
       obtain a class model that you can instantiate from a toplevel class declaration:

           class Foo<T>(){
               string => "Hello, our T is: ``typeLiteral<T>()``";
           }

           void test(){
               // We need to apply the Integer closed type to the Foo declaration in order to get the Foo<Integer> closed type
               Class<Foo<Integer>,[]> classModel = `class Foo`.classApply<Foo<Integer>,[]>(`Integer`);
               // This will print: Hello, our T is: ceylon.language::Integer
               print(classModel());
           }

       <a name="member-sample"></a>
       ### Usage sample for member classes

       For member classes it is a bit longer, because member classes need to be applied not only their type arguments but also
       the containing type, so you should use [[memberClassApply]] and start by giving the containing closed type:

           class Outer(){
               shared class Inner(){
                   string => "Hello";
               }
           }

           void test(){
               // apply the containing closed type `Outer` to the member class declaration `Outer.Inner`
               MemberClass<Outer,Outer.Inner,[]> memberClassModel = `class Outer.Inner`.memberClassApply<Outer,Outer.Inner,[]>(`Outer`);
               // We now have a MemberClass, which needs to be applied to a containing instance in order to become an
               // invokable class model:
               Class<Outer.Inner,[]> boundMemberClassModel = memberClassModel(Outer());
               // This will print: Hello
               print(boundMemberClassModel());
           }
       """
    shared sealed interface ClassDeclaration
            of ClassWithInitializerDeclaration | ClassWithConstructorsDeclaration
            satisfies ClassOrInterfaceDeclaration {

        "A constructor declaration representing the class initializer
         (for a class with a parameter list) or
         the default constructor, or null if the class lacks
         both a parameter list and a default constructor."
        since("1.2.0")
        shared formal CallableConstructorDeclaration? defaultConstructor;

        "The list of parameter declarations for this class.
         Returns `null` if the class lacks both a parameter list and a
         default constructor."
        since("1.2.0")
        shared formal FunctionOrValueDeclaration[]? parameterDeclarations;

        "Gets a parameter declaration by name.
         Returns `null` if this class lacks both a parameter list and a
         default constructor,
         or if no such parameter exists in the parameter list."
        since("1.2.0")
        shared formal FunctionOrValueDeclaration? getParameterDeclaration(String name);

        "True if the current declaration is an annotation class or function."
        since("1.2.0")
        shared formal Boolean annotation;

        "True if the class has an [[abstract|ceylon.language::abstract]] annotation."
        shared formal Boolean abstract;

        "True if the class is serializable class."
        since("1.2.0")
        shared formal Boolean serializable;

        "True if the class is an anonymous class, as is the case for the class of object value declarations."
        shared formal Boolean anonymous;

        "This anonymous class' object value declaration if this class is an anonymous class. `null` otherwise."
        since("1.1.0")
        shared formal ValueDeclaration? objectValue;

        "True if the class has a [[final|ceylon.language::final]] annotation."
        shared formal Boolean final;

        "Applies the given closed type arguments to this toplevel class declaration in order to obtain a class model.
         See [this code sample](#toplevel-sample) for an example on how to use this."
        throws(`class IncompatibleTypeException`,
            "If the specified `Type` or `Arguments` type arguments are not
             compatible with the actual result.")
        throws(`class TypeApplicationException`,
                "If the specified closed type argument values are not compatible
                 with the actual result's type parameters.")
        shared formal Class<Type, Arguments> classApply
                <Type=Anything, Arguments=Nothing>
                (AppliedType<>* typeArguments)
                    given Arguments satisfies Anything[];

        "Applies the given closed container type and type arguments to this member class declaration in order to obtain a member class model.
         See [this code sample](#member-sample) for an example on how to use this."
        throws(`class IncompatibleTypeException`,
            "If the specified `Container`, `Type` or `Arguments` type arguments
             are not compatible with the actual result.")
        throws(`class TypeApplicationException`,
                "If the specified closed container type or type argument values
                 are not compatible with the actual result's container type or
                 type parameters.")
        shared formal MemberClass<Container, Type, Arguments> memberClassApply
                <Container=Nothing, Type=Anything, Arguments=Nothing>
                (AppliedType<Object> containerType, AppliedType<>* typeArguments)
                    given Arguments satisfies Anything[];

        "Creates a new instance of this toplevel class,
         by applying the specified type arguments and value arguments."
        throws(`class IncompatibleTypeException`,
            "If the specified type or value arguments are not compatible with
             this toplevel class, or if the class lacks both a parameter list
             and a default constructor.")
        shared default Object instantiate(AppliedType<>[] typeArguments = [], Anything* arguments)
            => classApply<Object, Nothing>(*typeArguments).apply(*arguments);

        "Creates a new instance of this member class, by applying the specified
         type arguments and value arguments."
        throws(`class IncompatibleTypeException`,
            "If the specified container, type or value arguments are not
             compatible with this method, or if the class lacks both a parameter list
             and a default constructor.")
        shared default Object memberInstantiate
                (Object container, AppliedType<>[] typeArguments = [], Anything* arguments)
                    => memberClassApply<Nothing, Object, Nothing>(`Nothing`, *typeArguments).bind(container).apply(*arguments);

        "Looks up a constructor declaration directly declared on this class, by name.
         Returns `null` if no such constructor matches.
         This includes unshared constructors but not inherited constructors
         (since constructors are not members)."
        since("1.2.0")
        shared formal <CallableConstructorDeclaration|ValueConstructorDeclaration>? getConstructorDeclaration(String name);

        "Returns the list of constructors declared on this class. This includes unshared constructors."
        since("1.2.0")
        shared formal ConstructorDeclaration[] constructorDeclarations();

        "Returns the list of constructors declared on this class that are annotated with the
         given `Annotation` type argument. This includes unshared constructors."
        since("1.2.0")
        shared formal ConstructorDeclaration[] annotatedConstructorDeclarations<Annotation>()
                given Annotation satisfies AnnotationType;
    }