Trait scala.reflect.api.Symbols
trait Symbols extends AnyRef
Type Members
abstract type ClassSymbol >: Null <: Universe.ClassSymbolApi with Universe.TypeSymbol
trait ClassSymbolApi extends Universe.TypeSymbolApi
The API of class symbols. The main source of information about symbols is the Symbols page.
Class Symbol defines isXXX test methods such as isPublic or isFinal, params and returnType methods for method symbols, baseClasses for class symbols and so on. Some of these methods don't make sense for certain subclasses of Symbol and return NoSymbol, Nil or other empty values.
abstract type MethodSymbol >: Null <: Universe.MethodSymbolApi with Universe.TermSymbol
trait MethodSymbolApi extends Universe.TermSymbolApi
The API of method symbols. The main source of information about symbols is the Symbols page.
Class Symbol defines isXXX test methods such as isPublic or isFinal, params and returnType methods for method symbols, baseClasses for class symbols and so on. Some of these methods don't make sense for certain subclasses of Symbol and return NoSymbol, Nil or other empty values.
abstract type ModuleSymbol >: Null <: Universe.ModuleSymbolApi with Universe.TermSymbol
trait ModuleSymbolApi extends Universe.TermSymbolApi
The API of module symbols. The main source of information about symbols is the Symbols page.
Class Symbol defines isXXX test methods such as isPublic or isFinal, params and returnType methods for method symbols, baseClasses for class symbols and so on. Some of these methods don't make sense for certain subclasses of Symbol and return NoSymbol, Nil or other empty values.
abstract type Symbol >: Null <: Universe.SymbolApi
trait SymbolApi extends AnyRef
The API of symbols. The main source of information about symbols is the Symbols page.
Class Symbol defines isXXX test methods such as isPublic or isFinal, params and returnType methods for method symbols, baseClasses for class symbols and so on. Some of these methods don't make sense for certain subclasses of Symbol and return NoSymbol, Nil or other empty values.
abstract type TermSymbol >: Null <: Universe.TermSymbolApi with Universe.Symbol
trait TermSymbolApi extends Universe.SymbolApi
The API of term symbols. The main source of information about symbols is the Symbols page.
Class Symbol defines isXXX test methods such as isPublic or isFinal, params and returnType methods for method symbols, baseClasses for class symbols and so on. Some of these methods don't make sense for certain subclasses of Symbol and return NoSymbol, Nil or other empty values.
abstract type TypeSymbol >: Null <: Universe.TypeSymbolApi with Universe.Symbol
trait TypeSymbolApi extends Universe.SymbolApi
The API of type symbols. The main source of information about symbols is the Symbols page.
Class Symbol defines isXXX test methods such as isPublic or isFinal, params and returnType methods for method symbols, baseClasses for class symbols and so on. Some of these methods don't make sense for certain subclasses of Symbol and return NoSymbol, Nil or other empty values.
Abstract Value Members
abstract val NoSymbol: Universe.Symbol
A special "missing" symbol. Commonly used in the API to denote a default or empty value.
Concrete Value Members
final def !=(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
final def ##(): Int
- Definition Classes
- AnyRef → Any
def +(other: String): String
def ->[B](y: B): (Symbols, B)
final def ==(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
final def asInstanceOf[T0]: T0
- Definition Classes
- Any
def clone(): AnyRef
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws( ... ) @native()
def ensuring(cond: (Symbols) ⇒ Boolean, msg: ⇒ Any): Symbols
def ensuring(cond: (Symbols) ⇒ Boolean): Symbols
def ensuring(cond: Boolean, msg: ⇒ Any): Symbols
def ensuring(cond: Boolean): Symbols
final def eq(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
def equals(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
def finalize(): Unit
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws( classOf[java.lang.Throwable] )
def formatted(fmtstr: String): String
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
- @throws( ... ) @native()
def →[B](y: B): (Symbols, B)
© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.12.9/scala-reflect/scala/reflect/api/Symbols.html
EXPERIMENTAL
This trait defines symbols and operations on them.
Symbols are used to establish bindings between a name and the entity it refers to, such as a class or a method. Anything you define and can give a name to in Scala has an associated symbol.
Symbols contain all available information about the declaration of an entity (class/object/trait etc.) or a member (vals/vars/defs etc.), and as such are an integral abstraction central to both runtime reflection and macros.
A symbol can provide a wealth of information ranging from the basic
namemethod available on all symbols to other, more involved, concepts such as getting thebaseClassesfromClassSymbol. Other common use cases of symbols include inspecting members' signatures, getting type parameters of a class, getting the parameter type of a method or finding out the type of a field.Example usage of runtime reflection; getting a method's type signature:
scala> import scala.reflect.runtime.universe._ import scala.reflect.runtime.universe._ scala> class C[T] { def test[U](x: T)(y: U): Int = ??? } defined class C scala> val test = typeOf[C[Int]].member(TermName("test")).asMethod test: reflect.runtime.universe.MethodSymbol = method test scala> test.info res0: reflect.runtime.universe.Type = [U](x: T)(y: U)scala.IntSymbols are organized in a hierarchy. For example, a symbol that represents a parameter of a method is owned by the corresponding method symbol, a method symbol is owned by its enclosing class, a class is owned by a containing package and so on.
Certain types of tree nodes, such as Ident (references to identifiers) and Select (references to members) expose method
symbolto obtain the symbol that represents their declaration. During the typechecking phase, the compiler looks up the symbol based on the name and scope and sets thesymbolfield of tree nodes.For more information about
Symbolusage and attached intricacies, see the Reflection Guide: Symbols