A function declaration.

Usage sample for toplevel function

Because some functions have type parameters, getting a model requires applying type arguments to the function declaration with apply() in order to be able to invoke that function. For example, here is how you would obtain a function model that you can invoke from a toplevel function declaration:

String foo<T>(){
    return "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> function model
    Function<String,[]> functionModel = `function foo`.apply<String,[]>(`Integer`);
    // This will print: Hello, our T is: ceylon.language::Integer
    print(functionModel());
}

Usage sample for methods

For methods it is a bit longer, because methods need to be applied not only their type arguments but also the containing type, so you should use memberApply() and start by giving the containing closed type:

class Outer(){
    shared String hello() => "Hello";
}

void test(){
    // apply the containing closed type `Outer` to the method declaration `Outer.hello`
    Method<Outer,String,[]> methodModel = `function Outer.hello`.memberApply<Outer,String,[]>(`Outer`);
    // We now have a Method, which needs to be applied to a containing instance in order to become an
    // invokable function:
    Function<String,[]> boundMethodModel = methodModel(Outer());
    // This will print: Hello
    print(boundMethodModel());
}

no type hierarchy

Attributes
annotationSource Codeshared formal Boolean annotation

True if the current declaration is an annotation class or function.

parameterDeclarationsSource Codeshared formal FunctionOrValueDeclaration[] parameterDeclarations

The list of parameter declarations for this functional declaration.

Inherited Attributes
Attributes inherited from: Object
Attributes inherited from: GenericDeclaration
Methods
applySource Codeshared formal FunctionModel<Return,Arguments>&Applicable<Return,Arguments> apply<Return = Anything, Arguments = Nothing>(Type<Anything>[] typeArguments)

Applies the given closed type arguments to this function declaration in order to obtain a function model. See this code sample for an example on how to use this.

Throws
  • IncompatibleTypeException

    If the specified Return or Arguments type arguments are not compatible with the actual result.

  • TypeApplicationException

    If the specified closed type argument values are not compatible with the actual result's type parameters.

Since 1.2.0
getParameterDeclarationSource Codeshared formal FunctionOrValueDeclaration? getParameterDeclaration(String name)

Gets a parameter declaration by name. Returns null if no such parameter exists.

invokeSource Codeshared default Anything invoke(Type<Anything>[] typeArguments = [], Anything[] arguments)

Invokes the underlying toplevel function, by applying the specified type arguments and value arguments.

Parameters:
  • typeArguments = []
Throws
Since 1.2.0
memberApplySource Codeshared formal FunctionModel<Return,Arguments>&Qualified<FunctionModel<Return,Arguments>,Container> memberApply<Container = Nothing, Return = Anything, Arguments = Nothing>(Type<Object> containerType, Type<Anything>[] typeArguments)

Applies the given closed container type and type arguments to this method declaration in order to obtain a method model. See this code sample for an example on how to use this.

Throws
  • IncompatibleTypeException

    If the specified Container, Return or Arguments type arguments are not compatible with the actual result.

  • TypeApplicationException

    If the specified closed container type or type argument values are not compatible with the actual result's container type or type parameters.

Since 1.2.0
memberInvokeSource Codeshared formal Anything memberInvoke(Object container, Type<Anything>[] typeArguments = [], Anything[] arguments)

Invokes the underlying method, by applying the specified type arguments and value arguments.

Parameters:
  • typeArguments = []
Throws
Since 1.2.0
Inherited Methods
Methods inherited from: Object
Methods inherited from: GenericDeclaration