Reading annotations
In Crystal, you normally invoke a method on an object in order to access some data stored within. Annotations are no different. The Annotation type exposes three methods that can be used to access the data defined on the annotation in different ways. However, before you can access the data on the annotation, you need to get a reference to an Annotation instance. This can be accomplished by passing the Annotation type to the #annotation method defined on the types that support annotations, including TypeNode, Def, and MetaVar. For example, we can use this method to print the annotation applied to a specific class or method, if present:
annotation MyAnnotation; end
@[MyAnnotation]
class MyClass
def foo
{{pp @type.annotation MyAnnotation}}
{{pp @def.annotation MyAnnotation}}
end
end
MyClass.new.foo
The #annotation method will return NilLiteral if no annotation of the provided type is applied...
