Does this type conform to given type argument that?

Is this type equivalent to given type argument that?

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

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 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]

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.

Does this type contain a reference to given symbol?

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.

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.

The scope that holds the definitions comprising the type.

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

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)))

Is there part of this type which satisfies predicate p?

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 = ???
     | }
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 // vanilla NullaryMethodType
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

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

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

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

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

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 members.sorted to get an ordered list of members.

Provides an alternate if type is NoType.

For a method or poly type, a list of its value parameter sections, the empty list of lists 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) = ??? }
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

Substitute symbols 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.

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

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

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)

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

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

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

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.

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.

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)))