scala.reflect.macros

# Attachments

#### abstract class Attachments extends AnyRef

EXPERIMENTAL

Attachments provide a way to associate custom metadata with symbols and trees.

Along with `symbol` and `tpe`, which represent core metadata of trees, each tree carries the `attachments` field that can store other metadata: compiler-defined (e.g. positions) or user-defined. Same story is true for symbols, which also have extensible metadata by the virtue of the same `attachments` field.

Typically attachments just store a scala.reflect.api.Position, but they can be extended to encompass arbitrary payloads. Payloads are stored in type-indexed slots, which can be read with `get[T]` and written with `update[T]` and `remove[T]`.

This API doesn't have much use in the runtime reflection API (the scala.reflect.api package), but it might be of help for macro writers, providing a way to coordinate multiple macros operating on the same code. Therefore the `attachments` field is only declared in trees and symbols belonging to scala.reflect.macros.Universe.

Self Type
  Attachments

Linear Supertypes
AnyRef, Any
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Inherited

1. Attachments
2. AnyRef
3. Any

Implicitly

1. by any2stringadd
2. by StringFormat
3. by Ensuring
4. by ArrowAssoc

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### Instance Constructors

1. #### new Attachments()

### Type Members

1. #### abstract type Pos >: Null

   The position type of this attachment

### Abstract Value Members

1. #### abstract def pos: Pos

   The underlying position

2. #### abstract def withPos(newPos: Pos): Attachments { type Pos = Attachments.this.Pos }

   Creates a copy of this attachment with the position replaced by `newPos`

### Concrete Value Members

1. #### final def !=(arg0: Any): Boolean

   Definition Classes
     AnyRef → Any

2. #### final def ##(): Int

   Definition Classes
     AnyRef → Any

3. #### def +(other: String): String

   Implicit information
     This member is added by an implicit conversion from Attachments to any2stringadd[Attachments] performed by method any2stringadd in scala.Predef.
   Definition Classes
     any2stringadd

4. #### def ->[B](y: B): (Attachments, B)

   Implicit information
     This member is added by an implicit conversion from Attachments to ArrowAssoc[Attachments] performed by method ArrowAssoc in scala.Predef.
   Definition Classes
     ArrowAssoc
   Annotations
     @inline()

5. #### final def ==(arg0: Any): Boolean

   Definition Classes
     AnyRef → Any

6. #### def all: Set[Any]

   The underlying payload with the guarantee that no two elements have the same type.

7. #### final def asInstanceOf[T0]: T0

   Definition Classes
     Any

8. #### def clone(): AnyRef

   Attributes
     protected[java.lang]
   Definition Classes
     AnyRef
   Annotations
     @throws( ... )

9. #### def contains[T](implicit arg0: ClassTag[T]): Boolean

   Check underlying payload contains an instance of type `T`.

10. #### def ensuring(cond: (Attachments) ⇒ Boolean, msg: ⇒ Any): Attachments

    Implicit information
      This member is added by an implicit conversion from Attachments to Ensuring[Attachments] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring

11. #### def ensuring(cond: (Attachments) ⇒ Boolean): Attachments

    Implicit information
      This member is added by an implicit conversion from Attachments to Ensuring[Attachments] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring

12. #### def ensuring(cond: Boolean, msg: ⇒ Any): Attachments

    Implicit information
      This member is added by an implicit conversion from Attachments to Ensuring[Attachments] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring

13. #### def ensuring(cond: Boolean): Attachments

    Implicit information
      This member is added by an implicit conversion from Attachments to Ensuring[Attachments] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring

14. #### final def eq(arg0: AnyRef): Boolean

    Definition Classes
      AnyRef

15. #### def equals(arg0: Any): Boolean

    Definition Classes
      AnyRef → Any

16. #### def finalize(): Unit

    Attributes
      protected[java.lang]
    Definition Classes
      AnyRef
    Annotations
      @throws( classOf[java.lang.Throwable] )

17. #### def formatted(fmtstr: String): String

    Implicit information
      This member is added by an implicit conversion from Attachments to StringFormat[Attachments] performed by method StringFormat in scala.Predef.
    Definition Classes
      StringFormat
    Annotations
      @inline()

18. #### def get[T](implicit arg0: ClassTag[T]): Option[T]

    An underlying payload of the given class type `T`.

19. #### final def getClass(): Class[_]

    Definition Classes
      AnyRef → Any

20. #### def hashCode(): Int

    Definition Classes
      AnyRef → Any

21. #### def isEmpty: Boolean

22. #### final def isInstanceOf[T0]: Boolean

    Definition Classes
      Any

23. #### final def ne(arg0: AnyRef): Boolean

    Definition Classes
      AnyRef

24. #### final def notify(): Unit

    Definition Classes
      AnyRef

25. #### final def notifyAll(): Unit

    Definition Classes
      AnyRef

26. #### def remove[T](implicit arg0: ClassTag[T]): Attachments { type Pos = Attachments.this.Pos }

    Creates a copy of this attachment with the payload of the given class type `T` removed.

27. #### final def synchronized[T0](arg0: ⇒ T0): T0

    Definition Classes
      AnyRef

28. #### def toString(): String

    Definition Classes
      AnyRef → Any

29. #### def update[T](attachment: T)(implicit arg0: ClassTag[T]): Attachments { type Pos = Attachments.this.Pos }

    Creates a copy of this attachment with the payload slot of T added/updated with the provided value.

    Creates a copy of this attachment with the payload slot of T added/updated with the provided value. Replaces an existing payload of the same type, if exists.

30. #### final def wait(): Unit

    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

31. #### final def wait(arg0: Long, arg1: Int): Unit

    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

32. #### final def wait(arg0: Long): Unit

    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

33. #### def →[B](y: B): (Attachments, B)

    Implicit information
      This member is added by an implicit conversion from Attachments to ArrowAssoc[Attachments] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
      ArrowAssoc

### Inherited from AnyRef

### Inherited from Any

### Inherited by implicit conversion any2stringadd from Attachments to any2stringadd[Attachments]

### Inherited by implicit conversion StringFormat from Attachments to StringFormat[Attachments]

### Inherited by implicit conversion Ensuring from Attachments to Ensuring[Attachments]

### Inherited by implicit conversion ArrowAssoc from Attachments to ArrowAssoc[Attachments]

### Ungrouped