The API of FlagSet instances.
The API of FlagSet instances.
The main source of information about flag sets is the scala.reflect.api.FlagSets page.
An abstract type representing sets of flags (like private, final, etc.) that apply to definition trees and symbols
All possible values that can constitute flag sets.
All possible values that can constitute flag sets. The main source of information about flag sets is the scala.reflect.api.FlagSets page.
A module that contains all possible values that can constitute flag sets.
The empty set of flags
The API of FlagSet instances.
Test two objects for inequality.
Test two objects for inequality.
true if !(this == that), false otherwise.
Equivalent to x.hashCode except for boxed numeric types and null.
Equivalent to x.hashCode except for boxed numeric types and null.
For numerics, it returns a hash value which is consistent
with value equality: if two value type instances compare
as true, then ## will produce the same hash value for each
of them.
For null returns a hashcode where null.hashCode throws a
NullPointerException.
a hash value consistent with ==
The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).
The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).
true if the receiver object is equivalent to the argument; false otherwise.
Cast the receiver object to be of type T0.
Cast the receiver object to be of type T0.
Note that the success of a cast at runtime is modulo Scala's erasure semantics.
Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at
runtime, while the expression List(1).asInstanceOf[List[String]] will not.
In the latter example, because the type argument is erased as part of compilation it is
not possible to check whether the contents of the list are of the requested type.
the receiver object.
ClassCastException if the receiver object is not an instance of the erasure of type T0.
Create a copy of the receiver object.
Create a copy of the receiver object.
The default implementation of the clone method is platform dependent.
a copy of the receiver object.
not specified by SLS as a member of AnyRef
Tests whether the argument (that) is a reference to the receiver object (this).
Tests whether the argument (that) is a reference to the receiver object (this).
The eq method implements an equivalence relation on
non-null instances of AnyRef, and has three additional properties:
x and y of type AnyRef, multiple invocations of
x.eq(y) consistently returns true or consistently returns false.x of type AnyRef, x.eq(null) and null.eq(x) returns false.null.eq(null) returns true. When overriding the equals or hashCode methods, it is important to ensure that their behavior is
consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they
should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).
true if the argument is a reference to the receiver object; false otherwise.
The equality method for reference types.
Called by the garbage collector on the receiver object when there are no more references to the object.
Called by the garbage collector on the receiver object when there are no more references to the object.
The details of when and if the finalize method is invoked, as
well as the interaction between finalize and non-local returns
and exceptions, are all platform dependent.
not specified by SLS as a member of AnyRef
A representation that corresponds to the dynamic class of the receiver object.
A representation that corresponds to the dynamic class of the receiver object.
The nature of the representation is platform dependent.
a representation that corresponds to the dynamic class of the receiver object.
not specified by SLS as a member of AnyRef
The hashCode method for reference types.
Test whether the dynamic type of the receiver object is T0.
Test whether the dynamic type of the receiver object is T0.
Note that the result of the test is modulo Scala's erasure semantics.
Therefore the expression 1.isInstanceOf[String] will return false, while the
expression List(1).isInstanceOf[List[String]] will return true.
In the latter example, because the type argument is erased as part of compilation it is
not possible to check whether the contents of the list are of the specified type.
true if the receiver object is an instance of erasure of type T0; false otherwise.
Equivalent to !(this eq that).
Equivalent to !(this eq that).
true if the argument is not a reference to the receiver object; false otherwise.
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up a single thread that is waiting on the receiver object's monitor.
not specified by SLS as a member of AnyRef
Wakes up all threads that are waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
not specified by SLS as a member of AnyRef
Creates a String representation of this object.
Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.
a String representation of the object.
EXPERIMENTAL
The trait that defines flag sets and operations on them.
Flags are used to provide modifiers for abstract syntax trees that represent definitions via theflagsfield of scala.reflect.api.Trees#Modifiers. Trees that accept modifiers are:For example, to create a class named
Cone would write something like:ClassDef(Modifiers(NoFlags), TypeName("C"), Nil, ...)Here, the flag set is empty.
To make
Cprivate, one would write something like:ClassDef(Modifiers(PRIVATE), TypeName("C"), Nil, ...)Flags can also be combined with the vertical bar operator (
|). For example, a private final class is written something like:ClassDef(Modifiers(PRIVATE | FINAL), TypeName("C"), Nil, ...)The list of all available flags is defined in scala.reflect.api.FlagSets#FlagValues, available via scala.reflect.api.FlagSets#Flag. (Typically one writes a wildcard import for this, e.g.
import scala.reflect.runtime.universe.Flag._).Definition trees are compiled down to symbols, so flags on modifiers of these trees are transformed into flags on the resulting symbols. Unlike trees, symbols don't expose flags, but rather provide
isXXXtest methods (e.g.isFinalcan be used to test finality). These test methods might require an upcast withasTerm,asTypeorasClassas some flags only make sense for certain kinds of symbols.Of Note: This part of the Reflection API is being considered as a candidate for redesign. It is quite possible that in future releases of the reflection API, flag sets could be replaced with something else.
For more details about
FlagSets and other aspects of Scala reflection, see the Reflection Guide