Packages

trait InternalApi extends AnyRef

Reflection API exhibits a tension inherent to experimental things: on the one hand we want it to grow into a beautiful and robust API, but on the other hand we have to deal with immaturity of underlying mechanisms by providing not very pretty solutions to enable important use cases.

In Scala 2.10, which was our first stab at reflection API, we didn't have a systematic approach to dealing with this tension, sometimes exposing too much of internals (e.g. Symbol.deSkolemize) and sometimes exposing too little (e.g. there's still no facility to change owners, to do typing transformations, etc). This resulted in certain confusion with some internal APIs living among public ones, scaring the newcomers, and some internal APIs only available via casting, which requires intimate knowledge of the compiler and breaks compatibility guarantees.

This led to creation of the internal API module for the reflection API, which provides advanced APIs necessary for macros that push boundaries of the state of the art, clearly demarcating them from the more or less straightforward rest and providing compatibility guarantees on par with the rest of the reflection API (full compatibility within minor releases, best effort towards backward compatibility within major releases, clear replacement path in case of rare incompatible changes in major releases).

The internal module itself (the value that implements InternalApi) isn't defined here, in scala.reflect.api.Universe, but is provided on per-implementation basis. Runtime API endpoint (scala.reflect.runtime.universe) provides universe.compat: InternalApi, whereas compile-time API endpoints (instances of scala.reflect.macros.Context) provide c.compat: ContextInternalApi, which extends InternalApi with additional universe-specific and context-specific functionality.

Self Type
Universe.InternalApi
Source
Internals.scala
Linear Supertypes
AnyRef, Any
Known Subclasses
ContextInternalApi, MacroInternalApi
Type Hierarchy
Ordering
  1. Grouped
  2. Alphabetic
  3. By Inheritance
Inherited
  1. InternalApi
  2. AnyRef
  3. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. Protected

TagInterop

  1. def manifestToTypeTag[T](mirror: Any, manifest: Manifest[T]): Universe.TypeTag[T]

    Convert a scala.reflect.Manifest to a scala.reflect.api.TypeTags#TypeTag.

    Convert a scala.reflect.Manifest to a scala.reflect.api.TypeTags#TypeTag.

    Compiler usually generates these conversions automatically, when a manifest for a type T is in scope, and an implicit of type TypeTag[T] is requested, but this method can also be called manually. For example:

    manifestToTypeTag(scala.reflect.runtime.currentMirror, implicitly[Manifest[String]])
  2. def typeTagToManifest[T](mirror: Any, tag: Universe.TypeTag[T])(implicit arg0: ClassTag[T]): Manifest[T]

    Convert a scala.reflect.api.TypeTags#TypeTag to a scala.reflect.Manifest.

    Convert a scala.reflect.api.TypeTags#TypeTag to a scala.reflect.Manifest.

    Compiler usually generates these conversions automatically, when a type tag for a type T is in scope, and an implicit of type Manifest[T] is requested, but this method can also be called manually. For example:

    typeTagToManifest(scala.reflect.runtime.currentMirror, implicitly[TypeTag[String]])

TypeCreators

  1. abstract def existentialAbstraction(tparams: List[Universe.Symbol], tpe0: Universe.Type): Universe.Type

    A creator for existential types.

    A creator for existential types. This generates:

    tpe1 where { tparams }

    where tpe1 is the result of extrapolating tpe with regard to tparams. Extrapolating means that type variables in tparams occurring in covariant positions are replaced by upper bounds, (minus any SingletonClass markers), type variables in tparams occurring in contravariant positions are replaced by upper bounds, provided the resulting type is legal with regard to stability, and does not contain any type variable in tparams.

    The abstraction drops all type parameters that are not directly or indirectly referenced by type tpe1. If there are no remaining type parameters, simply returns result type tpe.

Ungrouped

  1. trait DecoratorApi extends AnyRef

    See also

    Decorators

  2. abstract type Decorators <: DecoratorApi

    Syntactic conveniences for additional internal APIs for trees, symbols and types

  1. abstract def annotatedType(annotations: List[Universe.Annotation], underlying: Universe.Type): Universe.AnnotatedType

    A creator for AnnotatedType types.

  2. abstract def asFreeTerm(symbol: Universe.Symbol): Universe.FreeTermSymbol

    This symbol cast to a free term symbol.

    This symbol cast to a free term symbol.

    Exceptions thrown

    ScalaReflectionException if isFreeTerm is false.

  3. abstract def asFreeType(symbol: Universe.Symbol): Universe.FreeTypeSymbol

    This symbol cast to a free type symbol.

    This symbol cast to a free type symbol.

    Exceptions thrown

    ScalaReflectionException if isFreeType is false.

  4. abstract def boundedWildcardType(bounds: Universe.TypeBounds): Universe.BoundedWildcardType

    A creator for BoundedWildcardType types.

  5. abstract def classDef(sym: Universe.Symbol, impl: Universe.Template): Universe.ClassDef

    A factory method for ClassDef nodes.

  6. abstract def classInfoType(parents: List[Universe.Type], decls: Universe.Scope, typeSymbol: Universe.Symbol): Universe.ClassInfoType

    A creator for ClassInfoType types.

  7. abstract def constantType(value: Universe.Constant): Universe.ConstantType

    A creator for ConstantType types.

  8. abstract def createImporter(from0: Universe): Universe.Importer { val from: from0.type }

    Creates an importer that moves reflection artifacts between universes.

    Creates an importer that moves reflection artifacts between universes.

    See also

    Importer

  9. abstract def deSkolemize(symbol: Universe.Symbol): Universe.Symbol

    If this symbol is a skolem, its corresponding type parameter, otherwise the symbol itself.

    If this symbol is a skolem, its corresponding type parameter, otherwise the symbol itself.

    To quote Martin Odersky, skolems are synthetic type "constants" that are copies of existentially bound or universally bound type variables. E.g. if one is inside the right-hand side of a method:

    def foo[T](x: T) = ... foo[List[T]]....

    the skolem named T refers to the unknown type instance of T when foo is called. It needs to be different from the type parameter because in a recursive call as in the foo[List[T]] above the type parameter gets substituted with List[T], but the type skolem stays what it is.

    The other form of skolem is an existential skolem. Say one has a function

    def bar(xs: List[T] forSome { type T }) = xs.head

    then each occurrence of xs on the right will have type List[T'] where T' is a fresh copy of T.

  10. abstract val decorators: Decorators

    See also

    Decorators

  11. abstract def defDef(sym: Universe.Symbol, rhs: (List[List[Universe.Symbol]]) => Universe.Tree): Universe.DefDef

    A factory method for DefDef nodes.

  12. abstract def defDef(sym: Universe.Symbol, rhs: Universe.Tree): Universe.DefDef

    A factory method for DefDef nodes.

  13. abstract def defDef(sym: Universe.Symbol, mods: Universe.Modifiers, rhs: Universe.Tree): Universe.DefDef

    A factory method for DefDef nodes.

  14. abstract def defDef(sym: Universe.Symbol, vparamss: List[List[Universe.ValDef]], rhs: Universe.Tree): Universe.DefDef

    A factory method for DefDef nodes.

  15. abstract def defDef(sym: Universe.Symbol, mods: Universe.Modifiers, vparamss: List[List[Universe.ValDef]], rhs: Universe.Tree): Universe.DefDef

    A factory method for DefDef nodes.

  16. abstract def existentialType(quantified: List[Universe.Symbol], underlying: Universe.Type): Universe.ExistentialType

    A creator for ExistentialType types.

  17. abstract def flags(symbol: Universe.Symbol): Universe.FlagSet

    Returns internal flags associated with the symbol.

  18. abstract def freeTerms(tree: Universe.Tree): List[Universe.FreeTermSymbol]

    Extracts free term symbols from a tree that is reified or contains reified subtrees.

  19. abstract def freeTypes(tree: Universe.Tree): List[Universe.FreeTypeSymbol]

    Extracts free type symbols from a tree that is reified or contains reified subtrees.

  20. abstract def fullyInitialize(scope: Universe.Scope): scope.type

    Calls initialize on all the symbols that the scope consists of.

  21. abstract def fullyInitialize(tp: Universe.Type): tp.type

    Calls initialize on all the value and type parameters of the type.

  22. abstract def fullyInitialize(symbol: Universe.Symbol): symbol.type

    Calls initialize on the owner and all the value and type parameters of the symbol.

  23. abstract def initialize(symbol: Universe.Symbol): symbol.type

    Forces all outstanding completers associated with this symbol.

    Forces all outstanding completers associated with this symbol. After this call returns, the symbol becomes immutable and thread-safe.

  24. abstract def intersectionType(tps: List[Universe.Type], owner: Universe.Symbol): Universe.Type

    A creator for intersection type where intersections of a single type are replaced by the type itself, and repeated parent classes are merged.

    A creator for intersection type where intersections of a single type are replaced by the type itself, and repeated parent classes are merged.

    !!! Repeated parent classes are not merged - is this a bug in the comment or in the code?

  25. abstract def intersectionType(tps: List[Universe.Type]): Universe.Type

    A creator for intersection type where intersections of a single type are replaced by the type itself.

  26. abstract def isErroneous(symbol: Universe.Symbol): Boolean

    Does this symbol or its underlying type represent a typechecking error?

  27. abstract def isFreeTerm(symbol: Universe.Symbol): Boolean

    Does this symbol represent a free term captured by reification? If yes, isTerm is also guaranteed to be true.

  28. abstract def isFreeType(symbol: Universe.Symbol): Boolean

    Does this symbol represent a free type captured by reification? If yes, isType is also guaranteed to be true.

  29. abstract def isSkolem(symbol: Universe.Symbol): Boolean

    Does this symbol represent the definition of a skolem? Skolems are used during typechecking to represent type parameters viewed from inside their scopes.

  30. abstract def labelDef(sym: Universe.Symbol, params: List[Universe.Symbol], rhs: Universe.Tree): Universe.LabelDef

    A factory method for LabelDef nodes.

  31. abstract def methodType(params: List[Universe.Symbol], resultType: Universe.Type): Universe.MethodType

    A creator for MethodType types.

  32. abstract def moduleDef(sym: Universe.Symbol, impl: Universe.Template): Universe.ModuleDef

    A factory method for ModuleDef nodes.

  33. abstract def newClassSymbol(owner: Universe.Symbol, name: Universe.TypeName, pos: Universe.Position = NoPosition, flags: Universe.FlagSet = NoFlags): Universe.ClassSymbol
  34. abstract def newFreeTerm(name: String, value: => Any, flags: Universe.FlagSet = NoFlags, origin: String = null): Universe.FreeTermSymbol
  35. abstract def newFreeType(name: String, flags: Universe.FlagSet = NoFlags, origin: String = null): Universe.FreeTypeSymbol
  36. abstract def newMethodSymbol(owner: Universe.Symbol, name: Universe.TermName, pos: Universe.Position = NoPosition, flags: Universe.FlagSet = NoFlags): Universe.MethodSymbol
  37. abstract def newModuleAndClassSymbol(owner: Universe.Symbol, name: Universe.Name, pos: Universe.Position = NoPosition, flags: Universe.FlagSet = NoFlags): (Universe.ModuleSymbol, Universe.ClassSymbol)
  38. abstract def newScopeWith(elems: Universe.Symbol*): Universe.Scope

    Create a new scope with the given initial elements.

  39. abstract def newTermSymbol(owner: Universe.Symbol, name: Universe.TermName, pos: Universe.Position = NoPosition, flags: Universe.FlagSet = NoFlags): Universe.TermSymbol
  40. abstract def newTypeSymbol(owner: Universe.Symbol, name: Universe.TypeName, pos: Universe.Position = NoPosition, flags: Universe.FlagSet = NoFlags): Universe.TypeSymbol
  41. abstract def nullaryMethodType(resultType: Universe.Type): Universe.NullaryMethodType

    A creator for NullaryMethodType types.

  42. abstract def polyType(tparams: List[Universe.Symbol], tpe: Universe.Type): Universe.PolyType

    A creator for type parameterizations that strips empty type parameter lists.

    A creator for type parameterizations that strips empty type parameter lists. Use this factory method to indicate the type has kind * (it's a polymorphic value) until we start tracking explicit kinds equivalent to typeFun (except that the latter requires tparams nonEmpty).

  43. abstract def refinedType(parents: List[Universe.Type], owner: Universe.Symbol, decls: Universe.Scope, pos: Universe.Position): Universe.Type

    A creator for RefinedType types.

  44. abstract def refinedType(parents: List[Universe.Type], owner: Universe.Symbol, decls: Universe.Scope): Universe.Type

    A creator for RefinedType types.

  45. abstract def refinedType(parents: List[Universe.Type], owner: Universe.Symbol): Universe.Type

    A creator for RefinedType types.

  46. abstract def refinedType(parents: List[Universe.Type], decls: Universe.Scope, clazz: Universe.Symbol): Universe.RefinedType

    A creator for RefinedType types.

  47. abstract def refinedType(parents: List[Universe.Type], decls: Universe.Scope): Universe.RefinedType

    A creator for RefinedType types.

  48. abstract val reificationSupport: Universe.ReificationSupportApi

    This is an internal implementation module.

  49. abstract def singleType(pre: Universe.Type, sym: Universe.Symbol): Universe.Type

    A creator for SingleType types.

  50. abstract def substituteSymbols(tree: Universe.Tree, from: List[Universe.Symbol], to: List[Universe.Symbol]): Universe.Tree

    Substitute symbols in to for corresponding occurrences of references to symbols from in this type.

  51. abstract def substituteThis(tree: Universe.Tree, clazz: Universe.Symbol, to: => Universe.Tree): Universe.Tree

    Substitute given tree to for occurrences of nodes that represent C.this, where C refers to the given class clazz.

  52. abstract def substituteTypes(tree: Universe.Tree, from: List[Universe.Symbol], to: List[Universe.Type]): Universe.Tree

    Substitute types in to for corresponding occurrences of references to symbols from in this tree.

  53. abstract def superType(thistpe: Universe.Type, supertpe: Universe.Type): Universe.Type

    A creator for SuperType types.

  54. abstract def thisType(sym: Universe.Symbol): Universe.Type

    A creator for ThisType types.

  55. abstract def typeBounds(lo: Universe.Type, hi: Universe.Type): Universe.TypeBounds

    A creator for TypeBounds types.

  56. abstract def typeDef(sym: Universe.Symbol): Universe.TypeDef

    A factory method for TypeDef nodes.

  57. abstract def typeDef(sym: Universe.Symbol, rhs: Universe.Tree): Universe.TypeDef

    A factory method for TypeDef nodes.

  58. abstract def typeRef(pre: Universe.Type, sym: Universe.Symbol, args: List[Universe.Type]): Universe.Type

    A creator for TypeRef types.

  59. abstract def valDef(sym: Universe.Symbol): Universe.ValDef

    A factory method for ValDef nodes.

  60. abstract def valDef(sym: Universe.Symbol, rhs: Universe.Tree): Universe.ValDef

    A factory method for ValDef nodes.