A definition representing a
function declaration.
An IFunctionDefinitionIFunctionNode.
For example, the function declaration
public function f(i:int):int;
creates a function definition whose base name is
"f", whose namespace reference is to the
public namespace, and whose type reference is named
"Function". It has an
IReference named
"int" representing its return type. It also owns one parameter definition named
"i".
A function definition is contained within a file scope, a package scope, a class scope, an interface scope, or a function scope; it contains a function scope.