Packages

  • package root
    Definition Classes
    root
  • package scala
    Definition Classes
    root
  • package reflect
    Definition Classes
    scala
  • package api

    EXPERIMENTAL

    EXPERIMENTAL

    The Scala Reflection API (located in scala-reflect.jar).

    In Scala 2.10.0, the Scala Reflection API and its implementation have an "experimental" status. This means that the API and the docs are not complete and can be changed in binary- and source-incompatible manner in 2.10.1. This also means that the implementation has some known issues.

    The following types are the backbone of the Scala Reflection API, and serve as a good starting point for information about Scala Reflection:

    For more information about Scala Reflection, see the Reflection Guide

    Definition Classes
    reflect
  • trait Annotations extends AnyRef

    EXPERIMENTAL

    EXPERIMENTAL

    This trait provides annotation support for the reflection API.

    In Scala, annotations belong to one of the two categories:

    • Java annotations: annotations on definitions produced by the Java compiler, i.e., subtypes of java.lang.annotation.Annotation attached to program definitions.
    • Scala annotations: annotations on definitions or types produced by the Scala compiler.

    When a Scala annotation that inherits from scala.annotation.StaticAnnotation 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 C is represented as q"@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 C to ann(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 via annotation.tree.children.tail.

    For more information about Annotations, see the Reflection Guide: Annotations, Names, Scopes, and More

    Definition Classes
    api
  • Annotation
  • AnnotationApi
  • AnnotationExtractor
  • JavaArgument
  • JavaArgumentApi

trait AnnotationApi extends AnyRef

The API of Annotation instances. The main source of information about annotations is the scala.reflect.api.Annotations page.

Source
Annotations.scala
Linear Supertypes
AnyRef, Any
Known Subclasses
Annotation
Type Hierarchy
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. AnnotationApi
  2. AnyRef
  3. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
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Visibility
  1. Public
  2. Protected

Abstract Value Members

  1. abstract def javaArgs: ListMap[Universe.Name, Universe.JavaArgument]

    Payload of the Java annotation: a list of name-value pairs.

    Payload of the Java annotation: a list of name-value pairs. Empty for Scala annotations.

    Annotations
    @deprecated
    Deprecated

    (Since version 2.11.0) use tree.children.tail instead

  2. abstract def scalaArgs: List[Universe.Tree]

    Payload of the Scala annotation: a list of abstract syntax trees that represent the argument.

    Payload of the Scala annotation: a list of abstract syntax trees that represent the argument. Empty for Java annotations.

    Annotations
    @deprecated
    Deprecated

    (Since version 2.11.0) use tree.children.tail instead

  3. abstract def tpe: Universe.Type

    The type of the annotation.

    The type of the annotation.

    Annotations
    @deprecated
    Deprecated

    (Since version 2.11.0) use tree.tpe instead

Concrete Value Members

  1. def tree: Universe.Tree

    The tree underlying the annotation.