abstract type ConstantType >: Null <: Universe.ConstantTypeApi with Universe.SingletonType
The ConstantType
type is not directly written in user programs, but arises as the type of a constant.
The REPL expresses constant types like Int(11)
. Here are some constants with their types:
1 ConstantType(Constant(1)) "abc" ConstantType(Constant("abc"))
- Source
- Types.scala
- Grouped
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- By Inheritance
- ConstantType
- <refinement>
- <refinement>
- SingletonTypeApi
- ConstantTypeApi
- TypeApi
- AnyRef
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Abstract Value Members
-
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
-
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
-
abstract
def
asSeenFrom(pre: Universe.Type, clazz: Universe.Symbol): Universe.Type
This type as seen from prefix
pre
and classclazz
.This type as seen from prefix
pre
and classclazz
. This means: Replace allThisType
s ofclazz
or one of its subclasses bypre
and instantiate all parameters by arguments ofpre
. Proceed analogously forThisType
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.
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.
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.
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?
Does this type contain a reference to given symbol?
- Definition Classes
- TypeApi
-
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
-
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
-
abstract
def
decls: Universe.MemberScope
A
Scope
containing directly declared members of this type.A
Scope
containing directly declared members of this type. Unlikemembers
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.
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.
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
?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.
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.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 onlyApply
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.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.
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).A
Scope
containing all members of this type (directly declared or inherited). Unlikedeclarations
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.
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.
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
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
-
abstract
def
substituteSymbols(from: List[Universe.Symbol], to: List[Universe.Symbol]): Universe.Type
Substitute symbols in
to
for corresponding occurrences of references to symbolsfrom
in this type.Substitute symbols in
to
for corresponding occurrences of references to symbolsfrom
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 symbolsfrom
in this type.Substitute types in
to
for corresponding occurrences of references to symbolsfrom
in this type.- Definition Classes
- TypeApi
-
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
-
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
-
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
-
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
-
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
-
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
-
abstract
def
value: Universe.Constant
The compile-time constant underlying this type.
The compile-time constant underlying this type.
- Definition Classes
- ConstantTypeApi
-
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
-
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
- 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.
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
-
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
- @native() @throws( ... )
-
final
def
eq(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
-
def
equals(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
-
def
finalize(): Unit
- Attributes
- protected[java.lang]
- Definition Classes
- AnyRef
- Annotations
- @throws( classOf[java.lang.Throwable] )
-
final
def
getClass(): Class[_]
- 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( ... )
-
final
def
wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
final
def
wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @native() @throws( ... )