Scala Reflection Library2.13.0 < Back
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  EXPERIMENTAL

  EXPERIMENTAL

  The base package for Scala macros.

  Macros are functions that are called by the compiler during compilation. Within these functions the programmer has access to compiler APIs. For example, it is possible to generate, analyze and typecheck code.

  See the Macros Guide on how to get started with Scala macros.

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    reflect
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    macros
-  package whitebox
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    macros
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t

scala.reflect.macros

# Enclosures

###

#### trait Enclosures extends AnyRef

EXPERIMENTAL

A slice of the Scala macros context that exposes enclosing trees (method, class, compilation unit and currently compiled macro application), the enclosing position of the macro expansion, as well as macros and implicits that are currently in-flight.

Starting from Scala 2.11.0, the APIs to get the trees enclosing by the current macro application are deprecated, and the reasons for that are two-fold. Firstly, we would like to move towards the philosophy of locally-expanded macros, as it has proven to be important for understanding of code. Secondly, within the current architecture of scalac, we are unable to have c.enclosingTree-style APIs working robustly. Required changes to the typechecker would greatly exceed the effort that we would like to expend on this feature given the existence of more pressing concerns at the moment. This is somewhat aligned with the overall evolution of macros during the 2.11 development cycle, where we played with `c.introduceTopLevel` and `c.introduceMember`, but at the end of the day decided to reject them.

If you're relying on the now deprecated APIs, consider using the new c.internal.enclosingOwner method that can be used to obtain the names of enclosing definitions. Alternatively try reformulating your macros in terms of completely local expansion and/or joining a discussion of a somewhat related potential language feature at https://groups.google.com/forum/#!topic/scala-debate/f4CLmYShX6Q. We also welcome questions and suggestions on our mailing lists, where we would be happy to further discuss this matter.

Self Type
  blackbox.Context
Source
  Enclosures.scala

Linear Supertypes
AnyRef, Any
Known Subclasses
Context, Context
Type Hierarchy
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2. By Inheritance

Inherited

1. Enclosures
2. AnyRef
3. Any

Implicitly

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

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Visibility

1. Public
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### Deprecated Type Members

1.  case class EnclosureException(expected: Class[_], enclosingTrees: List[blackbox.Context.Tree]) extends Exception with Product with Serializable

   Indicates than one of the enclosure methods failed to find a tree of required type among enclosing trees.

   Indicates than one of the enclosure methods failed to find a tree of required type among enclosing trees.

   Annotations
     @deprecated
   Deprecated

     (Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

   See also

     scala.reflect.macros.Enclosures

### Abstract Value Members

1.  abstract def enclosingMacros: List[blackbox.Context]

   Contexts that represent macros in-flight, including the current one.

   Contexts that represent macros in-flight, including the current one. Very much like a stack trace, but for macros only. Can be useful for interoperating with other macros and for imposing compiler-friendly limits on macro expansion.

   Is also priceless for emitting sane error messages for macros that are called by other macros on synthetic (i.e. position-less) trees. In that dire case navigate the `enclosingMacros` stack, and it will most likely contain at least one macro with a position-ful macro application. See `enclosingPosition` for a default implementation of this logic.

   Unlike `openMacros`, this is a val, which means that it gets initialized when the context is created and always stays the same regardless of whatever happens during macro expansion.

2.  abstract def enclosingPosition: blackbox.Context.Position

   Tries to guess a position for the enclosing application.

   Tries to guess a position for the enclosing application. But that is simple, right? Just dereference `pos` of `macroApplication`? Not really. If we're in a synthetic macro expansion (no positions), we must do our best to infer the position of something that triggered this expansion. Surprisingly, quite often we can do this by navigation the `enclosingMacros` stack.

3.  abstract def macroApplication: blackbox.Context.Tree

   The tree that undergoes macro expansion.

   The tree that undergoes macro expansion. Can be useful to get an offset or a range position of the entire tree being processed.

4.  abstract def enclosingClass: blackbox.Context.Tree

   Tree that corresponds to the enclosing class, or EmptyTree if not applicable.

   Tree that corresponds to the enclosing class, or EmptyTree if not applicable.

   Annotations
     @deprecated
   Deprecated

     (Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

   See also

     scala.reflect.macros.Enclosures

5.  abstract def enclosingDef: Universe.DefDef

   Tree that corresponds to the enclosing DefDef tree.

   Tree that corresponds to the enclosing DefDef tree. Throws `EnclosureException` if there's no such enclosing tree.

   Annotations
     @deprecated
   Deprecated

     (Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

   See also

     scala.reflect.macros.Enclosures

6.  abstract def enclosingImpl: Universe.ImplDef

   Tree that corresponds to the enclosing ImplDef tree (i.e.

   Tree that corresponds to the enclosing ImplDef tree (i.e. either ClassDef or ModuleDef). Throws `EnclosureException` if there's no such enclosing tree.

   Annotations
     @deprecated
   Deprecated

     (Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

   See also

     scala.reflect.macros.Enclosures

7.  abstract def enclosingMethod: blackbox.Context.Tree

   Tree that corresponds to the enclosing method, or EmptyTree if not applicable.

   Tree that corresponds to the enclosing method, or EmptyTree if not applicable.

   Annotations
     @deprecated
   Deprecated

     (Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

   See also

     scala.reflect.macros.Enclosures

8.  abstract def enclosingPackage: Universe.PackageDef

   Tree that corresponds to the enclosing PackageDef tree.

   Tree that corresponds to the enclosing PackageDef tree. Throws `EnclosureException` if there's no such enclosing tree.

   Annotations
     @deprecated
   Deprecated

     (Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

   See also

     scala.reflect.macros.Enclosures

9.  abstract def enclosingRun: blackbox.Context.Run

   Compilation run that contains this macro application.

   Compilation run that contains this macro application.

   Annotations
     @deprecated
   Deprecated

     (Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

   See also

     scala.reflect.macros.Enclosures

10.  abstract def enclosingTemplate: Universe.Template

    Tree that corresponds to the enclosing Template tree.

    Tree that corresponds to the enclosing Template tree. Throws `EnclosureException` if there's no such enclosing tree.

    Annotations
      @deprecated
    Deprecated

      (Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

    See also

      scala.reflect.macros.Enclosures

11.  abstract def enclosingUnit: blackbox.Context.CompilationUnit

    Compilation unit that contains this macro application.

    Compilation unit that contains this macro application.

    Annotations
      @deprecated
    Deprecated

      (Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

    See also

      scala.reflect.macros.Enclosures

### 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
     This member is added by an implicit conversion from Enclosures toany2stringadd[Enclosures] performed by method any2stringadd in scala.Predef.
   Definition Classes
     any2stringadd
4.  def ->[B](y: B): (Enclosures, B)
   Implicit
     This member is added by an implicit conversion from Enclosures toArrowAssoc[Enclosures] performed by method ArrowAssoc in scala.Predef.
   Definition Classes
     ArrowAssoc
   Annotations
     @inline()
5.  final def ==(arg0: Any): Boolean
   Definition Classes
     AnyRef → Any
6.  final def asInstanceOf[T0]: T0
   Definition Classes
     Any
7.  def clone(): AnyRef
   Attributes
     protected[java.lang]
   Definition Classes
     AnyRef
   Annotations
     @throws(classOf[java.lang.CloneNotSupportedException]) @native()
8.  def ensuring(cond: (Enclosures) => Boolean, msg: => Any): Enclosures
   Implicit
     This member is added by an implicit conversion from Enclosures toEnsuring[Enclosures] performed by method Ensuring in scala.Predef.
   Definition Classes
     Ensuring
9.  def ensuring(cond: (Enclosures) => Boolean): Enclosures
   Implicit
     This member is added by an implicit conversion from Enclosures toEnsuring[Enclosures] performed by method Ensuring in scala.Predef.
   Definition Classes
     Ensuring
10.  def ensuring(cond: Boolean, msg: => Any): Enclosures
    Implicit
      This member is added by an implicit conversion from Enclosures toEnsuring[Enclosures] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
11.  def ensuring(cond: Boolean): Enclosures
    Implicit
      This member is added by an implicit conversion from Enclosures toEnsuring[Enclosures] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
12.  final def eq(arg0: AnyRef): Boolean
    Definition Classes
      AnyRef
13.  def equals(arg0: AnyRef): Boolean
    Definition Classes
      AnyRef → Any
14.  def finalize(): Unit
    Attributes
      protected[java.lang]
    Definition Classes
      AnyRef
    Annotations
      @throws(classOf[java.lang.Throwable])
15.  def formatted(fmtstr: String): String
    Implicit
      This member is added by an implicit conversion from Enclosures toStringFormat[Enclosures] performed by method StringFormat in scala.Predef.
    Definition Classes
      StringFormat
    Annotations
      @inline()
16.  final def getClass(): Class[_ <: AnyRef]
    Definition Classes
      AnyRef → Any
    Annotations
      @native()
17.  def hashCode(): Int
    Definition Classes
      AnyRef → Any
    Annotations
      @native()
18.  final def isInstanceOf[T0]: Boolean
    Definition Classes
      Any
19.  final def ne(arg0: AnyRef): Boolean
    Definition Classes
      AnyRef
20.  final def notify(): Unit
    Definition Classes
      AnyRef
    Annotations
      @native()
21.  final def notifyAll(): Unit
    Definition Classes
      AnyRef
    Annotations
      @native()
22.  final def synchronized[T0](arg0: => T0): T0
    Definition Classes
      AnyRef
23.  def toString(): String
    Definition Classes
      AnyRef → Any
24.  final def wait(): Unit
    Definition Classes
      AnyRef
    Annotations
      @throws(classOf[java.lang.InterruptedException])
25.  final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
      AnyRef
    Annotations
      @throws(classOf[java.lang.InterruptedException])
26.  final def wait(arg0: Long): Unit
    Definition Classes
      AnyRef
    Annotations
      @throws(classOf[java.lang.InterruptedException]) @native()

### Deprecated Value Members

1.  def →[B](y: B): (Enclosures, B)
   Implicit
     This member is added by an implicit conversion from Enclosures toArrowAssoc[Enclosures] performed by method ArrowAssoc in scala.Predef.
   Definition Classes
     ArrowAssoc
   Annotations
     @deprecated
   Deprecated

     (Since version 2.13.0) Use `->` instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.

### Inherited from AnyRef

### Inherited from Any

### Inherited by implicit conversion any2stringadd fromEnclosures to any2stringadd[Enclosures]

### Inherited by implicit conversion StringFormat fromEnclosures to StringFormat[Enclosures]

### Inherited by implicit conversion Ensuring fromEnclosures to Ensuring[Enclosures]

### Inherited by implicit conversion ArrowAssoc fromEnclosures to ArrowAssoc[Enclosures]

### Ungrouped