A mirror that reflects the instance parts of a runtime class.
A mirror that reflects a field.
A mirror that reflects a runtime value.
A mirror that reflects a method.
The base type of all mirrors of this universe.
The base type of all mirrors of this universe.
This abstract type conforms the base interface for all mirrors defined in scala.reflect.api.Mirror
and is gradually refined in specific universes (e.g. Mirror
of a scala.reflect.api.JavaUniverse is capable of reflection).
A mirror that reflects a Scala object definition or the static parts of a runtime class.
A mirror that reflects instances and static classes.
Abstracts the runtime representation of a class on the underlying platform.
The API of a mirror for a reflective universe.
A mirror that reflects the instance or static parts of a runtime class.
The root mirror of this universe.
The root mirror of this universe. This mirror contains standard Scala classes and types such as Any
, AnyRef
, AnyVal
,
Nothing
, Null
, and all classes loaded from scala-library, which are shared across all mirrors within the enclosing universe.
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 ==
Test two objects for equality.
Test two objects for equality.
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.
if the receiver object is not an instance of the erasure of type T0
.
Create a copy of the receiver object.
Tests whether the argument (arg0
) is a reference to the receiver object (this
).
Tests whether the argument (arg0
) 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.
Returns string formatted according to given format
string.
Returns string formatted according to given format
string.
Format strings are as for String.format
(@see java.lang.String.format).
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.
(mirrors: StringAdd).self
(mirrors: StringFormat).self
(mirrors: ArrowAssoc[Mirrors]).x
(Since version 2.10.0) Use leftOfArrow
instead
(mirrors: Ensuring[Mirrors]).x
(Since version 2.10.0) Use resultOfEnsuring
instead
EXPERIMENTAL
This trait provides support for Mirrors in the Scala Reflection API.
Mirror
s are a central part of Scala Reflection. All information provided by reflection is made accessible throughMirror
s. Depending on the type of information to be obtained, or the reflective action to be taken, different flavors of mirrors must be used. "Classloader" mirrors can be used to obtain representations of types and members. From a classloaderMirror
, it's possible to obtain more specialized "invoker"Mirror
s (the most commonly-used mirrors), which implement reflective invocations, such as method/constructor calls and field accesses.The two flavors of mirrors:
staticClass
/staticModule
/staticPackage
).MethodMirror.apply
,FieldMirror.get
, etc). These "invoker" mirrors are the types of mirrors that are most commonly used.Compile-time Mirrors
Compile-time
Mirror
s make use of only classloaderMirror
s to loadSymbol
s by name.The entry point to classloader
Mirror
s is via scala.reflect.macros.Context#mirror. Typical methods which use classloaderMirror
s include scala.reflect.api.Mirror#staticClass, scala.reflect.api.Mirror#staticModule, and scala.reflect.api.Mirror#staticPackage. For example:Of Note: There are several high-level alternatives that one can use to avoid having to manually lookup symbols. For example,
typeOf[Location.type].termSymbol
(ortypeOf[Location].typeSymbol
if we needed aClassSymbol
), which are type safe since we don’t have to useString
s to lookup theSymbol
.Runtime Mirrors
Runtime
Mirror
s make use of both classloader and invokerMirror
s.The entry point to
Mirror
s for use at runtime is viaru.runtimeMirror(<classloader>)
, whereru
is scala.reflect.runtime.universe.The result of a scala.reflect.api.JavaMirrors#runtimeMirror call is a classloader mirror, of type scala.reflect.api.Mirrors#ReflectiveMirror, which can load symbols by names as discussed above (in the “Compile-time” section).
A classloader mirror can create invoker mirrors, which include: scala.reflect.api.Mirrors#InstanceMirror, scala.reflect.api.Mirrors#MethodMirror, scala.reflect.api.Mirrors#FieldMirror, scala.reflect.api.Mirrors#ClassMirror and scala.reflect.api.Mirrors#ModuleMirror.
Examples of how these two types of
Mirror
s interact are available below.Types of Mirrors, Their Use Cases & Examples
scala.reflect.api.Mirrors#ReflectiveMirror. Used for loading
Symbol
s by name, and as an entry point into invoker mirrors. Entry point:val m = ru.runtimeMirror(<classloader>)
. Example:scala.reflect.api.Mirrors#InstanceMirror. Used for creating invoker
Mirror
s for methods and fields and for inner classes and inner objects (modules). Entry point:val im = m.reflect(<value>)
. Example:scala.reflect.api.Mirrors#MethodMirror. Used for invoking instance methods (Scala only has instance methods-- methods of objects are instance methods of object instances, obtainable via
ModuleMirror.instance
). Entry point:val mm = im.reflectMethod(<method symbol>)
. Example:scala.reflect.api.Mirrors#FieldMirror. Used for getting/setting instance fields (Scala only has instance fields-- fields of objects are instance methods of object instances obtainable via ModuleMirror.instance). Entry point:
val fm = im.reflectMethod(<field or accessor symbol>)
. Example:scala.reflect.api.Mirrors#ClassMirror. Used for creating invoker mirrors for constructors. Entry points: for static classes
val cm1 = m.reflectClass(<class symbol>)
, for inner classesval mm2 = im.reflectClass(<module symbol>)
. Example:scala.reflect.api.Mirrors#ModuleMirror. Used for getting singleton instances of objects. Entry points: for static objects (modules)
val mm1 = m.reflectModule(<module symbol>)
, for inner objects (modules)val mm2 = im.reflectModule(<module symbol>)
. Example:For more information about
Mirrors
s, see the Reflection Guide: Mirrors