Packages

t

scala.reflect.api.Types

ExistentialTypeApi

trait ExistentialTypeApi extends Universe.TypeApi

The API that all existential types support. The main source of information about types is the scala.reflect.api.Types page.

Self Type
Universe.ExistentialType
Source
Types.scala
Linear Supertypes
Universe.TypeApi, AnyRef, Any
Known Subclasses
ExistentialType
Ordering
  1. Grouped
  2. Alphabetic
  3. By Inheritance
Inherited
  1. ExistentialTypeApi
  2. TypeApi
  3. AnyRef
  4. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. All

Abstract Value Members

  1. abstract def <:<(that: Universe.Type): Boolean

    Does this type conform to given type argument that?

    Does this type conform to given type argument that?

    Definition Classes
    TypeApi
  2. abstract def =:=(that: Universe.Type): Boolean

    Is this type equivalent to given type argument that?

    Is this type equivalent to given type argument that?

    Definition Classes
    TypeApi
  3. abstract def asSeenFrom(pre: Universe.Type, clazz: Universe.Symbol): Universe.Type

    This type as seen from prefix pre and class clazz.

    This type as seen from prefix pre and class clazz. This means: Replace all ThisTypes of clazz or one of its subclasses by pre and instantiate all parameters by arguments of pre. Proceed analogously for ThisTypes referring to outer classes.

    Example:

    scala> import scala.reflect.runtime.universe._
import scala.reflect.runtime.universe._

scala> class D[T] { def m: T = ??? }
defined class D

scala> class C extends D[Int]
defined class C

scala> val D = typeOf[D[_]].typeSymbol.asClass
D: reflect.runtime.universe.ClassSymbol = class D

scala> val C = typeOf[C].typeSymbol.asClass
C: reflect.runtime.universe.ClassSymbol = class C

scala> val T = D.typeParams(0).asType.toType
T: reflect.runtime.universe.Type = T

scala> T.asSeenFrom(ThisType(C), D)
res0: reflect.runtime.universe.Type = scala.Int
    Definition Classes
    TypeApi
  4. abstract def baseClasses: List[Universe.Symbol]

    The list of all base classes of this type (including its own typeSymbol) in linearization order, starting with the class itself and ending in class Any.

    The list of all base classes of this type (including its own typeSymbol) in linearization order, starting with the class itself and ending in class Any.

    Definition Classes
    TypeApi
  5. abstract def baseType(clazz: Universe.Symbol): Universe.Type

    The least type instance of given class which is a super-type of this type.

    The least type instance of given class which is a super-type of this type. Example:

    class D[T]
class C extends p.D[Int]
ThisType(C).baseType(D) = p.D[Int]
    Definition Classes
    TypeApi
  6. abstract def companion: Universe.Type

    Type signature of the companion of the underlying class symbol.

    Type signature of the companion of the underlying class symbol. NoType if the underlying symbol is not a class symbol, or if it doesn't have a companion.

    Definition Classes
    TypeApi
  7. abstract def contains(sym: Universe.Symbol): Boolean

    Does this type contain a reference to given symbol?

    Does this type contain a reference to given symbol?

    Definition Classes
    TypeApi
  8. abstract def dealias: Universe.Type

    Expands type aliases arising from type members.

    Expands type aliases arising from type members. Note that type aliases can hide beneath singleton types and singleton types can hide inside type aliases. Moreover, aliases might lurk in the upper bounds of abstract types. Therefore careful thought has to be applied to identify and carry out unwrapping logic specific to your use case.

    Definition Classes
    TypeApi
  9. abstract def decl(name: Universe.Name): Universe.Symbol

    The defined or declared members with name name in this type; an OverloadedSymbol if several exist, NoSymbol if none exist.

    The defined or declared members with name name in this type; an OverloadedSymbol if several exist, NoSymbol if none exist. Alternatives of overloaded symbol appear in the order they are declared.

    Definition Classes
    TypeApi
  10. abstract def decls: Universe.MemberScope

    A Scope containing directly declared members of this type.

    A Scope containing directly declared members of this type. Unlike members this method doesn't returns inherited members.

    Members in the returned scope might appear in arbitrary order. Use declarations.sorted to get an ordered list of members.

    Definition Classes
    TypeApi
  11. abstract def erasure: Universe.Type

    The erased type corresponding to this type after all transformations from Scala to Java have been performed.

    The erased type corresponding to this type after all transformations from Scala to Java have been performed.

    Definition Classes
    TypeApi
  12. abstract def etaExpand: Universe.Type

    Converts higher-kinded TypeRefs to PolyTypes.

    Converts higher-kinded TypeRefs to PolyTypes. Functions on types are also implemented as PolyTypes.

    Example: (in the below, <List> is the type constructor of List) TypeRef(pre, <List>, List()) is replaced by PolyType(X, TypeRef(pre, <List>, List(X)))

    Definition Classes
    TypeApi
  13. abstract def exists(p: (Universe.Type) ⇒ Boolean): Boolean

    Is there part of this type which satisfies predicate p?

    Is there part of this type which satisfies predicate p?

    Definition Classes
    TypeApi
  14. abstract def finalResultType: Universe.Type

    For a curried/nullary method or poly type its non-method result type, the type itself for all other types.

    For a curried/nullary method or poly type its non-method result type, the type itself for all other types.

    scala> class C {
     | def foo[T](x: T)(y: T) = ???
     | def bar: Int = ???
     | }
defined class C

scala> typeOf[C].member(TermName("foo")).asMethod
res0: reflect.runtime.universe.MethodSymbol = method foo

scala> res0.info // PolyType wrapping a MethodType
res1: reflect.runtime.universe.Type = [T](x: T)(y: T)scala.Nothing

scala> res1.resultType // MethodType wrapping a MethodType
res2: reflect.runtime.universe.Type = (x: T)(y: T)scala.Nothing

scala> res1.resultType.resultType // vanilla MethodType
res3: reflect.runtime.universe.Type = (y: T)scala.Nothing

scala> res1.resultType.resultType.resultType
res4: reflect.runtime.universe.Type = scala.Nothing

scala> res1.finalResultType
res5: reflect.runtime.universe.Type = scala.Nothing

scala> typeOf[C].member(TermName("bar")).asMethod
res6: reflect.runtime.universe.MethodSymbol = method bar

scala> res6.info
res7: reflect.runtime.universe.Type = => scala.Int

scala> res6.info.resultType
res8: reflect.runtime.universe.Type = scala.Int

scala> res6.info.finalResultType
res9: reflect.runtime.universe.Type = scala.Int
    Definition Classes
    TypeApi
    See also

    resultType

  15. abstract def find(p: (Universe.Type) ⇒ Boolean): Option[Universe.Type]

    Returns optionally first type (in a preorder traversal) which satisfies predicate p, or None if none exists.

    Returns optionally first type (in a preorder traversal) which satisfies predicate p, or None if none exists.

    Definition Classes
    TypeApi
  16. abstract def foreach(f: (Universe.Type) ⇒ Unit): Unit

    Apply f to each part of this type, for side effects only

    Apply f to each part of this type, for side effects only

    Definition Classes
    TypeApi
  17. abstract def map(f: (Universe.Type) ⇒ Universe.Type): Universe.Type

    Apply f to each part of this type, returning a new type.

    Apply f to each part of this type, returning a new type. children get mapped before their parents

    Definition Classes
    TypeApi
  18. abstract def member(name: Universe.Name): Universe.Symbol

    The member with given name, either directly declared or inherited, an OverloadedSymbol if several exist, NoSymbol if none exist.

    The member with given name, either directly declared or inherited, an OverloadedSymbol if several exist, NoSymbol if none exist.

    Definition Classes
    TypeApi
  19. abstract def members: Universe.MemberScope

    A Scope containing all members of this type (directly declared or inherited).

    A Scope containing all members of this type (directly declared or inherited). Unlike declarations this method also returns inherited members.

    Members in the returned scope might appear in arbitrary order. Use declarations.sorted to get an ordered list of members.

    Definition Classes
    TypeApi
  20. abstract def orElse(alt: ⇒ Universe.Type): Universe.Type

    Provides an alternate if type is NoType.

    Provides an alternate if type is NoType.

    Definition Classes
    TypeApi
  21. abstract def paramLists: List[List[Universe.Symbol]]

    For a method or poly type, a list of its value parameter sections, the empty list of lists for all other types.

    For a method or poly type, a list of its value parameter sections, the empty list of lists for all other types.

    Definition Classes
    TypeApi
  22. abstract def quantified: List[Universe.Symbol]

    The symbols corresponding to the forSome clauses of the existential type.

  23. abstract def resultType: Universe.Type

    For a (nullary) method or poly type, its direct result type (can be a MethodType if the method has multiple argument lists), the type itself for all other types.

    For a (nullary) method or poly type, its direct result type (can be a MethodType if the method has multiple argument lists), the type itself for all other types.

    scala> class C { def foo[T](x: T)(y: T) = ??? }
defined class C

scala> typeOf[C].member(TermName("foo")).asMethod
res0: reflect.runtime.universe.MethodSymbol = method foo

scala> res0.info // PolyType wrapping a MethodType
res1: reflect.runtime.universe.Type = [T](x: T)(y: T)scala.Nothing

scala> res1.resultType // MethodType wrapping a MethodType
res2: reflect.runtime.universe.Type = (x: T)(y: T)scala.Nothing

scala> res1.resultType.resultType // vanilla MethodType
res3: reflect.runtime.universe.Type = (y: T)scala.Nothing

scala> res1.resultType.resultType.resultType
res4: reflect.runtime.universe.Type = scala.Nothing

scala> res1.finalResultType
res5: reflect.runtime.universe.Type = scala.Nothing
    Definition Classes
    TypeApi
    See also

    finalResultType

  24. abstract def substituteSymbols(from: List[Universe.Symbol], to: List[Universe.Symbol]): Universe.Type

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

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

    Definition Classes
    TypeApi
  25. abstract def substituteTypes(from: List[Universe.Symbol], to: List[Universe.Type]): Universe.Type

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

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

    Definition Classes
    TypeApi
  26. abstract def takesTypeArgs: Boolean

    Is this type a type constructor that is missing its type arguments?

    Is this type a type constructor that is missing its type arguments?

    Definition Classes
    TypeApi
  27. abstract def termSymbol: Universe.Symbol

    The term symbol associated with the type, or NoSymbol for types that do not refer to a term symbol.

    The term symbol associated with the type, or NoSymbol for types that do not refer to a term symbol.

    Definition Classes
    TypeApi
  28. abstract def typeArgs: List[Universe.Type]

    List of type arguments ingrained in this type reference.

    List of type arguments ingrained in this type reference. Depending on your use case you might or might not want to call dealias first.

    scala> type T = List[Int]
defined type alias T

scala> typeOf[T].typeArgs
res0: List[reflect.runtime.universe.Type] = List()

scala> typeOf[T].dealias.typeArgs
res1: List[reflect.runtime.universe.Type] = List(scala.Int)
    Definition Classes
    TypeApi
  29. abstract def typeConstructor: Universe.Type

    Returns the corresponding type constructor (e.g.

    Returns the corresponding type constructor (e.g. List for List[T] or List[String])

    Definition Classes
    TypeApi
  30. abstract def typeParams: List[Universe.Symbol]

    For a poly type, its type parameters, the empty list for all other types.

    For a poly type, its type parameters, the empty list for all other types.

    Definition Classes
    TypeApi
  31. abstract def typeSymbol: Universe.Symbol

    The type symbol associated with the type, or NoSymbol for types that do not refer to a type symbol.

    The type symbol associated with the type, or NoSymbol for types that do not refer to a type symbol.

    Definition Classes
    TypeApi
  32. abstract def underlying: Universe.Type

    The underlying type of the existential type.

  33. abstract def weak_<:<(that: Universe.Type): Boolean

    Does this type weakly conform to given type argument that, i.e., either conforms in terms of <:< or both are primitive number types that conform according to Section "Weak Conformance" in the spec.

    Does this type weakly conform to given type argument that, i.e., either conforms in terms of <:< or both are primitive number types that conform according to Section "Weak Conformance" in the spec. For example, Int weak_<:< Long.

    Definition Classes
    TypeApi
  34. abstract def widen: Universe.Type

    If this is a singleton type, widen it to its nearest underlying non-singleton base type by applying one or more underlying dereferences.

    If this is a singleton type, widen it to its nearest underlying non-singleton base type by applying one or more underlying dereferences. If this is not a singleton type, returns this type itself.

    Example:

    class Outer { class C ; val x: C } val o: Outer <o.x.type>.widen = o.C

    Note that type aliases can hide beneath singleton types and singleton types can hide inside type aliases. Moreover, aliases might lurk in the upper bounds of abstract types. Therefore careful thought has to be applied to identify and carry out unwrapping logic specific to your use case.

    Definition Classes
    TypeApi
  35. abstract def declaration(name: Universe.Name): Universe.Symbol

    Definition Classes
    TypeApi
    Annotations
    @deprecated
    Deprecated

    (Since version 2.11.0) use decl instead

    See also

    decl

  36. abstract def declarations: Universe.MemberScope

    Definition Classes
    TypeApi
    Annotations
    @deprecated
    Deprecated

    (Since version 2.11.0) use decls instead

    See also

    decls

  37. abstract def normalize: Universe.Type

    Reduce to beta eta-long normal form.

    Reduce to beta eta-long normal form. Expands type aliases and converts higher-kinded TypeRefs to PolyTypes. Functions on types are also implemented as PolyTypes.

    Example: (in the below, <List> is the type constructor of List) TypeRef(pre, <List>, List()) is replaced by PolyType(X, TypeRef(pre, <List>, List(X)))

    Definition Classes
    TypeApi
    Annotations
    @deprecated
    Deprecated

    (Since version 2.11.0) use dealias or etaExpand instead

  38. abstract def paramss: List[List[Universe.Symbol]]

    Definition Classes
    TypeApi
    Annotations
    @deprecated
    Deprecated

    (Since version 2.11.0) use paramLists instead

    See also

    paramLists

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.ExistentialTypeApi to any2stringadd[Universe.ExistentialTypeApi] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ->[B](y: B): (Universe.ExistentialTypeApi, B)
    Implicit
    This member is added by an implicit conversion from Universe.ExistentialTypeApi to ArrowAssoc[Universe.ExistentialTypeApi] 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: (Universe.ExistentialTypeApi) ⇒ Boolean, msg: ⇒ Any): Universe.ExistentialTypeApi
    Implicit
    This member is added by an implicit conversion from Universe.ExistentialTypeApi to Ensuring[Universe.ExistentialTypeApi] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  9. def ensuring(cond: (Universe.ExistentialTypeApi) ⇒ Boolean): Universe.ExistentialTypeApi
    Implicit
    This member is added by an implicit conversion from Universe.ExistentialTypeApi to Ensuring[Universe.ExistentialTypeApi] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  10. def ensuring(cond: Boolean, msg: ⇒ Any): Universe.ExistentialTypeApi
    Implicit
    This member is added by an implicit conversion from Universe.ExistentialTypeApi to Ensuring[Universe.ExistentialTypeApi] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  11. def ensuring(cond: Boolean): Universe.ExistentialTypeApi
    Implicit
    This member is added by an implicit conversion from Universe.ExistentialTypeApi to Ensuring[Universe.ExistentialTypeApi] 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 Universe.ExistentialTypeApi to StringFormat[Universe.ExistentialTypeApi] 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): (Universe.ExistentialTypeApi, B)
    Implicit
    This member is added by an implicit conversion from Universe.ExistentialTypeApi to ArrowAssoc[Universe.ExistentialTypeApi] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc

Inherited from Universe.TypeApi

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd from Universe.ExistentialTypeApi to any2stringadd[Universe.ExistentialTypeApi]

Inherited by implicit conversion StringFormat from Universe.ExistentialTypeApi to StringFormat[Universe.ExistentialTypeApi]

Inherited by implicit conversion Ensuring from Universe.ExistentialTypeApi to Ensuring[Universe.ExistentialTypeApi]

Inherited by implicit conversion ArrowAssoc from Universe.ExistentialTypeApi to ArrowAssoc[Universe.ExistentialTypeApi]

Helpers

Ungrouped