The type of the symbol name. Can be either TermName
or TypeName
depending on whether this is a TermSymbol
or a TypeSymbol
.
Type name namespaces do not intersect with term name namespaces. This fact is reflected in different types for names of TermSymbol
and TypeSymbol
.
For a class: its companion object if exists. For a module or a module class: companion class of the module if exists. For a package or a package class: NoSymbol. For all others: NoSymbol.
Filters the underlying alternatives (or a single-element list composed of the symbol itself if the symbol is not overloaded). Returns an overloaded symbol is there are multiple matches. Returns a NoSymbol if there are no matches.
The type signature of this symbol.
This method always returns signatures in the most generic way possible, even if the underlying symbol is obtained from an instantiation of a generic type. For example, signature of the method def map[B](f: (A) => B): List[B]
, which refers to the type parameter A
of the declaring class List[A]
, will always feature A
, regardless of whether map
is loaded from the List[_]
or from List[Int]
. To get a signature with type parameters appropriately instantiated, one should use infoIn
.
Is this symbol abstract (i.e. an abstract class, an abstract method, value or type member)?
Does this method represent a constructor?
If owner
is a class, then this is a vanilla JVM constructor. If owner
is a trait, then this is a mixin constructor.
Is this symbol static (i.e. with no outer instance)? Q: When exactly is a sym marked as STATIC? A: If it's a member of a toplevel object, or of an object contained in a toplevel object, or any number of levels deep. http://groups.google.com/group/scala-internals/browse_thread/thread/d385bcd60b08faf6
Does this symbol represent a synthetic (i.e. a compiler-generated) entity? Examples of synthetic entities are accessors for vals and vars.
The owner of this symbol. This is the symbol that directly contains the current symbol's definition. The NoSymbol
symbol does not have an owner, and calling this method on one causes an internal error. The owner of the Scala root class scala.reflect.api.Mirror.RootClass and the Scala root object scala.reflect.api.Mirror.RootPackage is NoSymbol
. Every other symbol has a chain of owners that ends in scala.reflect.api.Mirror.RootClass.
Set when symbol has a modifier of the form private[X] or protected[X], NoSymbol otherwise.
Access level encoding: there are three scala flags (PRIVATE, PROTECTED, and LOCAL) which combine with value privateWithin (the "foo" in private[foo]) to define from where an entity can be accessed. The meanings are as follows:
PRIVATE access restricted to class only. PROTECTED access restricted to class and subclasses only. LOCAL can only be set in conjunction with PRIVATE or PROTECTED. Further restricts access to the same object instance.
In addition, privateWithin can be used to set a visibility barrier. When set, everything contained in the named enclosing package or class has access. It is incompatible with PRIVATE or LOCAL, but is additive with PROTECTED (i.e. if either the flags or privateWithin allow access, then it is allowed.)
The java access levels translate as follows:
java private: isPrivate && (privateWithin == NoSymbol) java package: !isPrivate && !isProtected && (privateWithin == enclosingPackage) java protected: isProtected && (privateWithin == enclosingPackage) java public: !isPrivate && !isProtected && (privateWithin == NoSymbol)
(Since version 2.11.0) use overrides
instead
Source file if this symbol is created during this compilation run, or a class file if this symbol is loaded from a *.class or *.jar.
The return type is scala.reflect.io.AbstractFile
, which belongs to an experimental part of Scala reflection. It should not be used unless you know what you are doing. In subsequent releases, this API will be refined and exposed as a part of scala.reflect.api.
(Since version 2.11.0) use pos.source.file
instead
For a class: the module or case class factory with the same name in the same package. For a module: the class with the same name in the same package. For all others: NoSymbol.
This API may return unexpected results for module classes, packages and package classes. Use companion
instead in order to get predictable results.
(Since version 2.11.0) use companion
instead, but beware of possible changes in behavior
This symbol cast to a ClassSymbol representing a class or trait.
ScalaReflectionException
if isClass
is false.
This symbol cast to a MethodSymbol.
ScalaReflectionException
if isMethod
is false.
This symbol cast to a ModuleSymbol defined by an object definition.
ScalaReflectionException
if isModule
is false.
This symbol cast to a TermSymbol.
ScalaReflectionException
if isTerm
is false.
This symbol cast to a TypeSymbol.
ScalaReflectionException
if isType
is false.
Does this symbol represent the definition of a module (i.e. it results from an object definition?). If yes, isTerm
is also guaranteed to be true.
Used to provide a better error message for asMethod
.
Does this symbol represent the definition of a term? Note that every symbol is either a term or a type. So for every symbol sym
(except for NoSymbol
), either sym.isTerm
is true or sym.isType
is true.
Does this symbol represent the definition of a type? Note that every symbol is either a term or a type. So for every symbol sym
(except for NoSymbol
), either sym.isTerm
is true or sym.isType
is true.
© 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/Symbols$SymbolApi.html
The API of symbols. The main source of information about symbols is the Symbols page.
Class Symbol defines
isXXX
test methods such asisPublic
orisFinal
,params
andreturnType
methods for method symbols,baseClasses
for class symbols and so on. Some of these methods don't make sense for certain subclasses ofSymbol
and returnNoSymbol
,Nil
or other empty values.