Trait scala.reflect.api.Types.ExistentialTypeApi
trait ExistentialTypeApi extends Universe.TypeApi
Abstract Value Members
abstract def <:<(that: Universe.Type): Boolean
Does this type conform to given type argument that
?
- Definition Classes
- TypeApi
abstract def =:=(that: Universe.Type): Boolean
Is this type equivalent to given type argument that
?
- Definition Classes
- TypeApi
abstract def asSeenFrom(pre: Universe.Type, clazz: Universe.Symbol): Universe.Type
This type as seen from prefix pre
and class clazz
. This means: Replace all ThisType
s of clazz
or one of its subclasses by pre
and instantiate all parameters by arguments of pre
. Proceed analogously for ThisType
s 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
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.
- Definition Classes
- TypeApi
abstract def baseType(clazz: Universe.Symbol): Universe.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
abstract def companion: Universe.Type
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
abstract def contains(sym: Universe.Symbol): Boolean
Does this type contain a reference to given symbol?
- Definition Classes
- TypeApi
abstract def dealias: Universe.Type
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
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. Alternatives of overloaded symbol appear in the order they are declared.
- Definition Classes
- TypeApi
abstract def decls: Universe.MemberScope
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
abstract def erasure: Universe.Type
The erased type corresponding to this type after all transformations from Scala to Java have been performed.
- Definition Classes
- TypeApi
abstract def etaExpand: Universe.Type
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
abstract def exists(p: (Universe.Type) => Boolean): Boolean
Is there part of this type which satisfies predicate p
?
- Definition Classes
- TypeApi
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.
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
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.
- Definition Classes
- TypeApi
abstract def foreach(f: (Universe.Type) => Unit): Unit
Apply f
to each part of this type, for side effects only
- Definition Classes
- TypeApi
abstract def map(f: (Universe.Type) => Universe.Type): Universe.Type
Apply f
to each part of this type, returning a new type. children get mapped before their parents
- Definition Classes
- TypeApi
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.
- Definition Classes
- TypeApi
abstract def members: Universe.MemberScope
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
abstract def orElse(alt: => Universe.Type): Universe.Type
Provides an alternate if type is NoType.
- Definition Classes
- TypeApi
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.
- Definition Classes
- TypeApi
abstract def quantified: List[Universe.Symbol]
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.
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
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.
- Definition Classes
- TypeApi
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.
- Definition Classes
- TypeApi
abstract def takesTypeArgs: Boolean
Is this type a type constructor that is missing its type arguments?
- Definition Classes
- TypeApi
abstract def termSymbol: Universe.Symbol
The term symbol associated with the type, or NoSymbol
for types that do not refer to a term symbol.
- Definition Classes
- TypeApi
abstract def typeArgs: List[Universe.Type]
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
abstract def typeConstructor: Universe.Type
Returns the corresponding type constructor (e.g. List for List[T] or List[String])
- Definition Classes
- TypeApi
abstract def typeParams: List[Universe.Symbol]
For a poly type, its type parameters, the empty list for all other types.
- Definition Classes
- TypeApi
abstract def typeSymbol: Universe.Symbol
The type symbol associated with the type, or NoSymbol
for types that do not refer to a type symbol.
- Definition Classes
- TypeApi
abstract def underlying: Universe.Type
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. For example, Int weak_<:< Long.
- Definition Classes
- TypeApi
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 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
abstract def declaration(name: Universe.Name): Universe.Symbol
abstract def declarations: Universe.MemberScope
abstract def normalize: Universe.Type
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
oretaExpand
instead
abstract def paramss: List[List[Universe.Symbol]]
- Definition Classes
- TypeApi
- Annotations
- @deprecated
- Deprecated
(Since version 2.11.0) use
paramLists
instead- 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 Universe.ExistentialTypeApi toany2stringadd[Universe.ExistentialTypeApi] performed by method any2stringadd in scala.Predef.
- Definition Classes
- any2stringadd
def ->[B](y: B): (Universe.ExistentialTypeApi, B)
- Implicit
- This member is added by an implicit conversion from Universe.ExistentialTypeApi toArrowAssoc[Universe.ExistentialTypeApi] 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[java.lang]
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.CloneNotSupportedException]) @native()
def ensuring(cond: (Universe.ExistentialTypeApi) => Boolean, msg: => Any): Universe.ExistentialTypeApi
- Implicit
- This member is added by an implicit conversion from Universe.ExistentialTypeApi toEnsuring[Universe.ExistentialTypeApi] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
def ensuring(cond: (Universe.ExistentialTypeApi) => Boolean): Universe.ExistentialTypeApi
- Implicit
- This member is added by an implicit conversion from Universe.ExistentialTypeApi toEnsuring[Universe.ExistentialTypeApi] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
def ensuring(cond: Boolean, msg: => Any): Universe.ExistentialTypeApi
- Implicit
- This member is added by an implicit conversion from Universe.ExistentialTypeApi toEnsuring[Universe.ExistentialTypeApi] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
def ensuring(cond: Boolean): Universe.ExistentialTypeApi
- Implicit
- This member is added by an implicit conversion from Universe.ExistentialTypeApi toEnsuring[Universe.ExistentialTypeApi] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
final def eq(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
def equals(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef → Any
def finalize(): Unit
- Attributes
- protected[java.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 Universe.ExistentialTypeApi toStringFormat[Universe.ExistentialTypeApi] performed by method StringFormat in scala.Predef.
- Definition Classes
- StringFormat
- Annotations
- @inline()
final def getClass(): Class[_ <: AnyRef]
- 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(classOf[java.lang.InterruptedException])
final def wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
final def wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException]) @native()
© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.13.0/scala-reflect/scala/reflect/api/Types$ExistentialTypeApi.html
The API that all existential types support. The main source of information about types is the scala.reflect.api.Types page.