scala.reflect.macros

# Reifiers

#### trait Reifiers extends AnyRef

EXPERIMENTAL

A slice of the Scala macros context that exposes functions to save reflection artifacts for runtime.

Self Type
  blackbox.Context
Source
  Reifiers.scala

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AnyRef, Any
Known Subclasses
Context, Context
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1. Reifiers
2. AnyRef
3. Any

Implicitly

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

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### Abstract Value Members

1. #### abstract def reifyEnclosingRuntimeClass: blackbox.Context.Tree

   Given a type, generate a tree that when compiled and executed produces the runtime class of the enclosing class or module.

   Given a type, generate a tree that when compiled and executed produces the runtime class of the enclosing class or module. Returns `EmptyTree` if there does not exist an enclosing class or module.

2. #### abstract def reifyRuntimeClass(tpe: blackbox.Context.Type, concrete: Boolean = true): blackbox.Context.Tree

   Given a type, generate a tree that when compiled and executed produces the runtime class of the original type.

   Given a type, generate a tree that when compiled and executed produces the runtime class of the original type. If `concrete` is true, then this function will bail on types, who refer to abstract types (like `ClassTag` does).

3. #### abstract def reifyTree(universe: blackbox.Context.Tree, mirror: blackbox.Context.Tree, tree: blackbox.Context.Tree): blackbox.Context.Tree

   Given a tree, generate a tree that when compiled and executed produces the original tree.

   Given a tree, generate a tree that when compiled and executed produces the original tree. For more information and examples see the documentation for `Universe.reify`.

   The produced tree will be bound to the specified `universe` and `mirror`. Possible values for `universe` include `universe.internal.gen.mkRuntimeUniverseRef`. Possible values for `mirror` include `EmptyTree` (in that case the reifier will automatically pick an appropriate mirror).

   This function is deeply connected to `Universe.reify`, a macro that reifies arbitrary expressions into runtime trees. They do very similar things (`Universe.reify` calls `Context.reifyTree` to implement itself), but they operate on different metalevels (see below).

   Let's study the differences between `Context.reifyTree` and `Universe.reify` on an example of using them inside a `fooMacro` macro:

   * Since reify itself is a macro, it will be executed when fooMacro is being compiled (metalevel -1) and will produce a tree that when evaluated during macro expansion of fooMacro (metalevel 0) will recreate the input tree.

   This provides a facility analogous to quasi-quoting. Writing "reify{ expr }" will generate an AST that represents expr. Afterwards this AST (or its parts) can be used to construct the return value of fooMacro.

   * reifyTree is evaluated during macro expansion (metalevel 0) and will produce a tree that when evaluated during the runtime of the program (metalevel 1) will recreate the input tree.

   This provides a way to retain certain trees from macro expansion time to be inspected later, in the runtime. For example, DSL authors may find it useful to capture DSL snippets into ASTs that are then processed at runtime in a domain-specific way.

   Also note the difference between universes of the runtime trees produced by two reifies:

   * The result of compiling and running the result of reify will be bound to the Universe that called reify. This is possible because it's a macro, so it can generate whatever code it wishes.

   * The result of compiling and running the result of reifyTree will be the `prefix` that needs to be passed explicitly. This happens because the Universe of the evaluated result is from a different metalevel than the Context the called reify.

   Typical usage of this function is to retain some of the trees received/created by a macro into the form that can be inspected (via pattern matching) or compiled/run (by a reflective ToolBox) during the runtime.

4. #### abstract def reifyType(universe: blackbox.Context.Tree, mirror: blackbox.Context.Tree, tpe: blackbox.Context.Type, concrete: Boolean = false): blackbox.Context.Tree

   Given a type, generate a tree that when compiled and executed produces the original type.

   Given a type, generate a tree that when compiled and executed produces the original type. The produced tree will be bound to the specified `universe` and `mirror`. For more information and examples see the documentation for `Context.reifyTree` and `Universe.reify`.

5. #### abstract def unreifyTree(tree: blackbox.Context.Tree): blackbox.Context.Tree

   Undoes reification of a tree.

   Undoes reification of a tree.

   This reversion doesn't simply restore the original tree (that would lose the context of reification), but does something more involved that conforms to the following laws:

   1) unreifyTree(reifyTree(tree)) != tree // unreified tree is tree + saved context // in current implementation, the result of unreify is opaque // i.e. there's no possibility to inspect underlying tree/context

   2) reifyTree(unreifyTree(reifyTree(tree))) == reifyTree(tree) // the result of reifying a tree in its original context equals to // the result of reifying a tree along with its saved context

   3) compileAndEval(unreifyTree(reifyTree(tree))) ~ compileAndEval(tree) // at runtime original and unreified trees are behaviorally equivalent

### 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 Reifiers to any2stringadd[Reifiers] performed by method any2stringadd in scala.Predef.
   Definition Classes
     any2stringadd

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

   Implicit information
     This member is added by an implicit conversion from Reifiers to ArrowAssoc[Reifiers] 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: (Reifiers) ⇒ Boolean, msg: ⇒ Any): Reifiers

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

9. #### def ensuring(cond: (Reifiers) ⇒ Boolean): Reifiers

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

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

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

11. #### def ensuring(cond: Boolean): Reifiers

    Implicit information
      This member is added by an implicit conversion from Reifiers to Ensuring[Reifiers] 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 information
      This member is added by an implicit conversion from Reifiers to StringFormat[Reifiers] 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): (Reifiers, B)

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

### Inherited from AnyRef

### Inherited from Any

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

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

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

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

### Ungrouped