Packages

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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  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
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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 to any2stringadd[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 to ArrowAssoc[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( ... )
  8. def ensuring(cond: (Enclosures) ⇒ Boolean, msg: ⇒ Any): Enclosures
    Implicit
    This member is added by an implicit conversion from Enclosures to Ensuring[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 to Ensuring[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 to Ensuring[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 to Ensuring[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: Any): 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 to StringFormat[Enclosures] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @inline()
  16. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
  17. def hashCode(): Int
    Definition Classes
    AnyRef → Any
  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
  21. final def notifyAll(): Unit
    Definition Classes
    AnyRef
  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( ... )
  25. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  26. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  27. def →[B](y: B): (Enclosures, B)
    Implicit
    This member is added by an implicit conversion from Enclosures to ArrowAssoc[Enclosures] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd from Enclosures to any2stringadd[Enclosures]

Inherited by implicit conversion StringFormat from Enclosures to StringFormat[Enclosures]

Inherited by implicit conversion Ensuring from Enclosures to Ensuring[Enclosures]

Inherited by implicit conversion ArrowAssoc from Enclosures to ArrowAssoc[Enclosures]

Ungrouped