Trait scala.reflect.macros.Enclosures
trait Enclosures extends AnyRef
Type Members
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.
- Annotations
- @deprecated
- Deprecated
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
- See also
Abstract Value Members
abstract def enclosingMacros: List[blackbox.Context]
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.
abstract def enclosingPosition: blackbox.Context.Position
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.
abstract def macroApplication: blackbox.Context.Tree
The tree that undergoes macro expansion. Can be useful to get an offset or a range position of the entire tree being processed.
abstract def enclosingClass: blackbox.Context.Tree
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
abstract def enclosingDef: Universe.DefDef
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
abstract def enclosingImpl: Universe.ImplDef
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
abstract def enclosingMethod: blackbox.Context.Tree
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
abstract def enclosingPackage: Universe.PackageDef
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
abstract def enclosingRun: blackbox.Context.Run
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
abstract def enclosingTemplate: Universe.Template
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
abstract def enclosingUnit: blackbox.Context.CompilationUnit
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
Concrete Value Members
final def !=(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
final def ##(): Int
- Definition Classes
- AnyRef → Any
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
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()
final def ==(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
final def asInstanceOf[T0]: T0
- Definition Classes
- Any
def clone(): AnyRef
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws( ... ) @native()
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
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
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
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
final def eq(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
def equals(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
def finalize(): Unit
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws( classOf[java.lang.Throwable] )
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()
final def getClass(): Class[_]
- Definition Classes
- AnyRef → Any
- Annotations
- @native()
def hashCode(): Int
- Definition Classes
- AnyRef → Any
- Annotations
- @native()
final def isInstanceOf[T0]: Boolean
- Definition Classes
- Any
final def ne(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
final def notify(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native()
final def notifyAll(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native()
final def synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
- AnyRef
def toString(): String
- Definition Classes
- AnyRef → Any
final def wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
final def wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
final def wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... ) @native()
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
© 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/macros/Enclosures.html
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.introduceTopLevelandc.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.