trait FlagSets extends AnyRef
EXPERIMENTAL
The trait that defines flag sets and operations on them.
Flag
s are used to provide modifiers for abstract syntax trees that represent definitions
via the flags
field of scala.reflect.api.Trees#Modifiers. Trees that accept modifiers are:
- scala.reflect.api.Trees#ClassDef. Classes and traits.
- scala.reflect.api.Trees#ModuleDef. Objects.
- scala.reflect.api.Trees#ValDef. Vals, vars, parameters and self-type annotations.
- scala.reflect.api.Trees#DefDef. Methods and constructors.
- scala.reflect.api.Trees#TypeDef. Type aliases, abstract type members and type parameters.
For example, to create a class named C
one would write something like:
ClassDef(Modifiers(NoFlags), TypeName("C"), Nil, ...)
Here, the flag set is empty.
To make C
private, 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 isXXX
test methods
(e.g. isFinal
can be used to test finality). These test methods might require an upcast with asTerm
,
asType
or asClass
as 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 FlagSet
s and other aspects of Scala reflection, see the
Reflection Guide
- Self Type
- Universe
- Source
- FlagSets.scala
- Grouped
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- By Inheritance
- FlagSets
- AnyRef
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- by any2stringadd
- by StringFormat
- by Ensuring
- by ArrowAssoc
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Type Members
-
trait
FlagOps
extends Any
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. -
abstract
type
FlagSet
An abstract type representing sets of flags (like private, final, etc.) that apply to definition trees and symbols
-
trait
FlagValues
extends AnyRef
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.
Abstract Value Members
-
abstract
val
Flag: Universe.FlagValues
A module that contains all possible values that can constitute flag sets.
-
abstract
val
NoFlags: Universe.FlagSet
The empty set of flags
-
implicit abstract
def
addFlagOps(left: Universe.FlagSet): Universe.FlagOps
The API of
FlagSet
instances.
Concrete Value Members
-
final
def
!=(arg0: Any): Boolean
Test two objects for inequality.
Test two objects for inequality.
- returns
true
if !(this == that), false otherwise.
- Definition Classes
- AnyRef → Any
-
final
def
##(): Int
Equivalent to
x.hashCode
except for boxed numeric types andnull
.Equivalent to
x.hashCode
except for boxed numeric types andnull
. 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. Fornull
returns a hashcode wherenull.hashCode
throws aNullPointerException
.- returns
a hash value consistent with ==
- Definition Classes
- AnyRef → Any
- def +(other: String): String
- def ->[B](y: B): (FlagSets, B)
-
final
def
==(arg0: Any): Boolean
The expression
x == that
is equivalent toif (x eq null) that eq null else x.equals(that)
.The expression
x == that
is equivalent toif (x eq null) that eq null else x.equals(that)
.- returns
true
if the receiver object is equivalent to the argument;false
otherwise.
- Definition Classes
- AnyRef → Any
-
final
def
asInstanceOf[T0]: T0
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 aClassCastException
at runtime, while the expressionList(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.- returns
the receiver object.
- Definition Classes
- Any
- Exceptions thrown
ClassCastException
if the receiver object is not an instance of the erasure of typeT0
.
-
def
clone(): AnyRef
Create a copy of the receiver object.
Create a copy of the receiver object.
The default implementation of the
clone
method is platform dependent.- returns
a copy of the receiver object.
- Attributes
- protected[java.lang]
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
- Note
not specified by SLS as a member of AnyRef
- def ensuring(cond: (FlagSets) ⇒ Boolean, msg: ⇒ Any): FlagSets
- def ensuring(cond: (FlagSets) ⇒ Boolean): FlagSets
- def ensuring(cond: Boolean, msg: ⇒ Any): FlagSets
- def ensuring(cond: Boolean): FlagSets
-
final
def
eq(arg0: AnyRef): Boolean
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 ofAnyRef
, and has three additional properties:- It is consistent: for any non-null instances
x
andy
of typeAnyRef
, multiple invocations ofx.eq(y)
consistently returnstrue
or consistently returnsfalse
. - For any non-null instance
x
of typeAnyRef
,x.eq(null)
andnull.eq(x)
returnsfalse
. null.eq(null)
returnstrue
.
When overriding the
equals
orhashCode
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
).- returns
true
if the argument is a reference to the receiver object;false
otherwise.
- Definition Classes
- AnyRef
- It is consistent: for any non-null instances
-
def
equals(arg0: Any): Boolean
The equality method for reference types.
-
def
finalize(): Unit
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 betweenfinalize
and non-local returns and exceptions, are all platform dependent.- Attributes
- protected[java.lang]
- Definition Classes
- AnyRef
- Annotations
- @throws( classOf[java.lang.Throwable] )
- Note
not specified by SLS as a member of AnyRef
- def formatted(fmtstr: String): String
-
final
def
getClass(): Class[_]
Returns the runtime class representation of the object.
Returns the runtime class representation of the object.
- returns
a class object corresponding to the runtime type of the receiver.
- Definition Classes
- AnyRef → Any
-
def
hashCode(): Int
The hashCode method for reference types.
-
final
def
isInstanceOf[T0]: Boolean
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 returnfalse
, while the expressionList(1).isInstanceOf[List[String]]
will returntrue
. 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.- returns
true
if the receiver object is an instance of erasure of typeT0
;false
otherwise.
- Definition Classes
- Any
-
final
def
ne(arg0: AnyRef): Boolean
Equivalent to
!(this eq that)
.Equivalent to
!(this eq that)
.- returns
true
if the argument is not a reference to the receiver object;false
otherwise.
- Definition Classes
- AnyRef
-
final
def
notify(): Unit
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.
- Definition Classes
- AnyRef
- Note
not specified by SLS as a member of AnyRef
-
final
def
notifyAll(): Unit
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.
- Definition Classes
- AnyRef
- Note
not specified by SLS as a member of AnyRef
-
final
def
synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
- AnyRef
-
def
toString(): String
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.
- returns
a String representation of the object.
- 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( ... )
- def →[B](y: B): (FlagSets, B)