Packages

  • package root
    Definition Classes
    root
  • package scala
    Definition Classes
    root
  • package reflect
    Definition Classes
    scala
  • package api

    EXPERIMENTAL

    EXPERIMENTAL

    The Scala Reflection API (located in scala-reflect.jar).

    In Scala 2.10.0, the Scala Reflection API and its implementation have an "experimental" status. This means that the API and the docs are not complete and can be changed in binary- and source-incompatible manner in 2.10.1. This also means that the implementation has some known issues.

    The following types are the backbone of the Scala Reflection API, and serve as a good starting point for information about Scala Reflection:

    For more information about Scala Reflection, see the Reflection Guide

    Definition Classes
    reflect
  • trait Printers extends AnyRef

    EXPERIMENTAL

    EXPERIMENTAL

    Utilities for nicely printing scala.reflect.api.Trees and scala.reflect.api.Types.

    Printing Trees

    The method show displays the "prettified" representation of reflection artifacts. This representation provides one with the desugared Java representation of Scala code. For example:

    scala> import scala.reflect.runtime.universe._
    import scala.reflect.runtime.universe._
    
    scala> def tree = reify{ final class C { def x = 2 } }.tree
    tree: reflect.runtime.universe.Tree
    
    scala> show(tree)
    res0: String =
    {
      final class C extends AnyRef {
        def <init>() = {
          super.<init>();
          ()
        };
        def x = 2
      };
      ()
    }

    The method showRaw displays internal structure of a given reflection object as a Scala abstract syntax tree (AST), the representation that the Scala typechecker operates on.

    Note, that while this representation appears to generate correct trees that one might think would be possible to use in a macro implementation, this is not usually the case. Symbols aren't fully represented (only their names are). Thus, this method is best-suited for use simply inspecting ASTs given some valid Scala code.

    scala> showRaw(tree)
    res1: String = Block(List(
      ClassDef(Modifiers(FINAL), TypeName("C"), List(), Template(
        List(Ident(TypeName("AnyRef"))),
        noSelfType,
        List(
          DefDef(Modifiers(), nme.CONSTRUCTOR, List(), List(List()), TypeTree(),
            Block(List(
              Apply(Select(Super(This(tpnme.EMPTY), tpnme.EMPTY), nme.CONSTRUCTOR), List())),
              Literal(Constant(())))),
          DefDef(Modifiers(), TermName("x"), List(), List(), TypeTree(),
            Literal(Constant(2))))))),
      Literal(Constant(())))

    The method showRaw can also print scala.reflect.api.Types next to the artifacts being inspected

    scala> import scala.tools.reflect.ToolBox // requires scala-compiler.jar
    import scala.tools.reflect.ToolBox
    
    scala> import scala.reflect.runtime.{currentMirror => cm}
    import scala.reflect.runtime.{currentMirror=>cm}
    
    scala> showRaw(cm.mkToolBox().typecheck(tree), printTypes = true)
    res2: String = Block[1](List(
      ClassDef[2](Modifiers(FINAL), TypeName("C"), List(), Template[3](
        List(Ident[4](TypeName("AnyRef"))),
        noSelfType,
        List(
          DefDef[2](Modifiers(), nme.CONSTRUCTOR, List(), List(List()), TypeTree[3](),
            Block[1](List(
              Apply[4](Select[5](Super[6](This[3](TypeName("C")), tpnme.EMPTY), ...))),
              Literal[1](Constant(())))),
          DefDef[2](Modifiers(), TermName("x"), List(), List(), TypeTree[7](),
            Literal[8](Constant(2))))))),
      Literal[1](Constant(())))
    [1] TypeRef(ThisType(scala), scala.Unit, List())
    [2] NoType
    [3] TypeRef(NoPrefix, TypeName("C"), List())
    [4] TypeRef(ThisType(java.lang), java.lang.Object, List())
    [5] MethodType(List(), TypeRef(ThisType(java.lang), java.lang.Object, List()))
    [6] SuperType(ThisType(TypeName("C")), TypeRef(... java.lang.Object ...))
    [7] TypeRef(ThisType(scala), scala.Int, List())
    [8] ConstantType(Constant(2))
    Printing Types

    The method show

    scala> import scala.reflect.runtime.universe._
    import scala.reflect.runtime.universe._
    
    scala> def tpe = typeOf[{ def x: Int; val y: List[Int] }]
    tpe: reflect.runtime.universe.Type
    
    scala> show(tpe)
    res0: String = scala.AnyRef{def x: Int; val y: scala.List[Int]}

    Like the method showRaw for scala.reflect.api.Trees, showRaw for scala.reflect.api.Types provides a visualization of the Scala AST operated on by the Scala typechecker.

    // showRaw has already been discussed above
    scala> showRaw(tpe)
    res1: String = RefinedType(
      List(TypeRef(ThisType(scala), TypeName("AnyRef"), List())),
      Scope(
        TermName("x"),
        TermName("y")))

    printIds and/or printKinds can additionally be supplied as arguments in a call to showRaw which additionally shows the unique identifiers of symbols.

    scala> showRaw(tpe, printIds = true, printKinds = true)
    res2: String = RefinedType(
      List(TypeRef(ThisType(scala#2043#PK), TypeName("AnyRef")#691#TPE, List())),
      Scope(
        TermName("x")#2540#METH,
        TermName("y")#2541#GET))

    For more details about Printers and other aspects of Scala reflection, see the Reflection Guide

    Definition Classes
    api
  • BooleanFlag
  • TreePrinter

trait TreePrinter extends AnyRef

Attributes
protected
Source
Printers.scala
Linear Supertypes
Type Hierarchy
Ordering
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  2. By Inheritance
Inherited
  1. TreePrinter
  2. AnyRef
  3. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
  1. Hide All
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Visibility
  1. Public
  2. Protected

Abstract Value Members

  1. abstract def print(args: Any*): Unit

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 Universe.TreePrinter toany2stringadd[Universe.TreePrinter] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ->[B](y: B): (Universe.TreePrinter, B)
    Implicit
    This member is added by an implicit conversion from Universe.TreePrinter toArrowAssoc[Universe.TreePrinter] 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[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.CloneNotSupportedException]) @native()
  8. def ensuring(cond: (Universe.TreePrinter) => Boolean, msg: => Any): Universe.TreePrinter
    Implicit
    This member is added by an implicit conversion from Universe.TreePrinter toEnsuring[Universe.TreePrinter] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  9. def ensuring(cond: (Universe.TreePrinter) => Boolean): Universe.TreePrinter
    Implicit
    This member is added by an implicit conversion from Universe.TreePrinter toEnsuring[Universe.TreePrinter] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  10. def ensuring(cond: Boolean, msg: => Any): Universe.TreePrinter
    Implicit
    This member is added by an implicit conversion from Universe.TreePrinter toEnsuring[Universe.TreePrinter] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  11. def ensuring(cond: Boolean): Universe.TreePrinter
    Implicit
    This member is added by an implicit conversion from Universe.TreePrinter toEnsuring[Universe.TreePrinter] 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[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 Universe.TreePrinter toStringFormat[Universe.TreePrinter] 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. val printIds: Boolean
    Attributes
    protected
  23. val printKinds: Boolean
    Attributes
    protected
  24. val printMirrors: Boolean
    Attributes
    protected
  25. val printOwners: Boolean
    Attributes
    protected
  26. val printPositions: Boolean
    Attributes
    protected
  27. val printTypes: Boolean
    Attributes
    protected
  28. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  29. def toString(): String
    Definition Classes
    AnyRef → Any
  30. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  31. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  32. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException]) @native()
  33. def withIds: TreePrinter.this.type
  34. def withKinds: TreePrinter.this.type
  35. def withMirrors: TreePrinter.this.type
  36. def withOwners: TreePrinter.this.type
  37. def withPositions: TreePrinter.this.type
  38. def withTypes: TreePrinter.this.type
  39. def withoutIds: TreePrinter.this.type
  40. def withoutKinds: TreePrinter.this.type
  41. def withoutMirrors: TreePrinter.this.type
  42. def withoutOwners: TreePrinter.this.type
  43. def withoutPositions: TreePrinter.this.type
  44. def withoutTypes: TreePrinter.this.type

Deprecated Value Members

  1. def [B](y: B): (Universe.TreePrinter, B)
    Implicit
    This member is added by an implicit conversion from Universe.TreePrinter toArrowAssoc[Universe.TreePrinter] 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 fromUniverse.TreePrinter to any2stringadd[Universe.TreePrinter]

Inherited by implicit conversion StringFormat fromUniverse.TreePrinter to StringFormat[Universe.TreePrinter]

Inherited by implicit conversion Ensuring fromUniverse.TreePrinter to Ensuring[Universe.TreePrinter]

Inherited by implicit conversion ArrowAssoc fromUniverse.TreePrinter to ArrowAssoc[Universe.TreePrinter]

Ungrouped