The API of Annotation instances. The main source of information about annotations is the scala.reflect.api.Annotations page.
An extractor class to create and pattern match with syntax Annotation(tpe, scalaArgs, javaArgs). Here, tpe is the annotation type, scalaArgs the payload of Scala annotations, and javaArgs the payload of Java annotations.
An array argument to a Java annotation as in @Target(value={TYPE,FIELD,METHOD,PARAMETER})
(Since version 2.11.0) use Annotation.tree to inspect annotation arguments
API of ArrayArgument instances. The main source of information about annotations is the scala.reflect.api.Annotations page.
(Since version 2.11.0) use Annotation.tree to inspect annotation arguments
An extractor class to create and pattern match with syntax ArrayArgument(args) where args is the argument array.
(Since version 2.11.0) use Annotation.tree to inspect annotation arguments
A Java annotation argument
(Since version 2.11.0) use Annotation.tree to inspect annotation arguments
Has no special methods. Is here to provides erased identity for CompoundType.
(Since version 2.11.0) use Annotation.tree to inspect annotation arguments
A literal argument to a Java annotation as "use X instead" in @Deprecated("use X instead")
(Since version 2.11.0) use Annotation.tree to inspect annotation arguments
The API of LiteralArgument instances. The main source of information about annotations is the scala.reflect.api.Annotations page.
(Since version 2.11.0) use Annotation.tree to inspect annotation arguments
An extractor class to create and pattern match with syntax LiteralArgument(value) where value is the constant argument.
(Since version 2.11.0) use Annotation.tree to inspect annotation arguments
A nested annotation argument to a Java annotation as @Nested in @Outer(@Nested).
(Since version 2.11.0) use Annotation.tree to inspect annotation arguments
API of NestedArgument instances. The main source of information about annotations is the scala.reflect.api.Annotations page.
(Since version 2.11.0) use Annotation.tree to inspect annotation arguments
An extractor class to create and pattern match with syntax NestedArgument(annotation) where annotation is the nested annotation.
(Since version 2.11.0) use Annotation.tree to inspect annotation arguments
The constructor/extractor for ArrayArgument instances.
(Since version 2.11.0) use Annotation.tree to inspect annotation arguments
The constructor/extractor for LiteralArgument instances.
(Since version 2.11.0) use Annotation.tree to inspect annotation arguments
The constructor/extractor for NestedArgument instances.
(Since version 2.11.0) use Annotation.tree to inspect annotation arguments
© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.12.9/scala-reflect/scala/reflect/api/Annotations.html
EXPERIMENTAL
This trait provides annotation support for the reflection API.
In Scala, annotations belong to one of the two categories:
When a Scala annotation that inherits from scala.annotation.StaticAnnotation or scala.annotation.ClassfileAnnotation is compiled, it is stored as special attributes in the corresponding classfile, and not as a Java annotation. Note that subclassing just scala.annotation.Annotation is not enough to have the corresponding metadata persisted for runtime reflection.
Both Java and Scala annotations are represented as typed trees carrying constructor invocations corresponding to the annotation. For instance, the annotation in
@ann(1, 2) class Cis represented asq"@new ann(1, 2)".Unlike Java reflection, Scala reflection does not support evaluation of constructor invocations stored in annotations into underlying objects. For instance it's impossible to go from
@ann(1, 2) class Ctoann(1, 2), so one has to analyze trees representing annotation arguments to manually extract corresponding values. Towards that end, arguments of an annotation can be obtained viaannotation.tree.children.tail.For more information about
Annotations, see the Reflection Guide: Annotations, Names, Scopes, and More