The type of class symbols representing class and trait definitions.
The API of class symbols.
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.
The type of method symbols representing def declarations.
The API of method symbols.
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.
The type of module symbols representing object declarations.
The API of module symbols.
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.
The type of symbols representing declarations.
The API of symbols.
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.
The type of term symbols representing val, var, def, and object declarations as well as packages and value parameters.
The API of term symbols.
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.
The type of type symbols representing type, class, and trait declarations, as well as type parameters.
The API of type symbols.
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.
A special "missing" symbol.
A special "missing" symbol. Commonly used in the API to denote a default or empty value.
The methods available for each reflection entity, without the implementation. Since the reflection entities are later overridden by runtime reflection and macros, their API counterparts guarantee a minimum set of methods that are implemented.
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
name
method available on all symbols to other, more involved, concepts such as getting thebaseClasses
fromClassSymbol
. 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:
Symbols 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
symbol
to 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 thesymbol
field of tree nodes.For more information about
Symbol
usage and attached intricacies, see the Reflection Guide: Symbols