scala.reflect
Members list
Type members
Classlikes
Attributes
- Source
- Manifest.scala
- Supertypes
-
trait Manifest[T]trait ClassTag[T]trait Equalstrait ClassManifestDeprecatedApis[T]trait OptManifest[T]trait Serializableclass Objecttrait Matchableclass AnyShow all
ClassManifestFactory
defines factory methods for manifests.
ClassManifestFactory
defines factory methods for manifests. It is intended for use by the compiler and should not be used in client code.
Unlike ClassManifest
, this factory isn't annotated with a deprecation warning. This is done to prevent avalanches of deprecation warnings in the code that calls methods with manifests.
In a perfect world, we would just remove the @deprecated annotation from ClassManifest
the object and then delete it in 2.11. After all, that object is explicitly marked as internal, so no one should use it. However a lot of existing libraries disregarded the Scaladoc that comes with ClassManifest
, so we need to somehow nudge them into migrating prior to removing stuff out of the blue. Hence we've introduced this design decision as the lesser of two evils.
Attributes
- Source
- ClassManifestDeprecatedApis.scala
- Supertypes
- Self type
-
ClassManifestFactory.type
A ClassTag[T]
stores the erased class of a given type T
, accessible via the runtimeClass
field.
A ClassTag[T]
stores the erased class of a given type T
, accessible via the runtimeClass
field. This is particularly useful for instantiating Array
s whose element types are unknown at compile time.
ClassTag
s are a weaker special case of scala.reflect.api.TypeTags.TypeTags, in that they wrap only the runtime class of a given type, whereas a TypeTag
contains all static type information. That is, ClassTag
s are constructed from knowing only the top-level class of a type, without necessarily knowing all of its argument types. This runtime information is enough for runtime Array
creation.
For example:
scala> def mkArray[T : ClassTag](elems: T*) = Array[T](elems: _*)
mkArray: [T](elems: T*)(implicit evidence$1: scala.reflect.ClassTag[T])Array[T]
scala> mkArray(42, 13)
res0: Array[Int] = Array(42, 13)
scala> mkArray("Japan","Brazil","Germany")
res1: Array[String] = Array(Japan, Brazil, Germany)
See scala.reflect.api.TypeTags for more examples, or the Reflection Guide: TypeTags for more details.
Attributes
- Companion
- object
- Source
- ClassTag.scala
- Supertypes
-
trait Equalstrait ClassManifestDeprecatedApis[T]trait OptManifest[T]trait Serializableclass Objecttrait Matchableclass AnyShow all
- Known subtypes
-
trait Manifest[T]class AnyValManifest[T]
Class tags corresponding to primitive types and constructor/extractor for ClassTags.
Class tags corresponding to primitive types and constructor/extractor for ClassTags.
Attributes
- Companion
- trait
- Source
- ClassTag.scala
- Supertypes
- Self type
-
ClassTag.type
A base trait of all Scala enum definitions
A Manifest[T]
is an opaque descriptor for type T.
A Manifest[T]
is an opaque descriptor for type T. Its supported use is to give access to the erasure of the type as a Class
instance, as is necessary for the creation of native Arrays
if the class is not known at compile time.
The type-relation operators <:<
and =:=
should be considered approximations only, as there are numerous aspects of type conformance which are not yet adequately represented in manifests.
Example usages:
def arr[T] = new Array[T](0) // does not compile
def arr[T](implicit m: Manifest[T]) = new Array[T](0) // compiles
def arr[T: Manifest] = new Array[T](0) // shorthand for the preceding
// Methods manifest and optManifest are in [[scala.Predef]].
def isApproxSubType[T: Manifest, U: Manifest] = manifest[T] <:< manifest[U]
isApproxSubType[List[String], List[AnyRef]] // true
isApproxSubType[List[String], List[Int]] // false
def methods[T: Manifest] = manifest[T].runtimeClass.getMethods
def retType[T: Manifest](name: String) =
methods[T] find (_.getName == name) map (_.getGenericReturnType)
retType[Map[_, _]]("values") // Some(scala.collection.Iterable<B>)
Attributes
- Companion
- object
- Source
- Manifest.scala
- Supertypes
-
trait ClassTag[T]trait Equalstrait ClassManifestDeprecatedApis[T]trait OptManifest[T]trait Serializableclass Objecttrait Matchableclass AnyShow all
- Known subtypes
-
class AnyValManifest[T]
The object Manifest
defines factory methods for manifests.
The object Manifest
defines factory methods for manifests. It is intended for use by the compiler and should not be used in client code.
Attributes
- Companion
- trait
- Source
- Manifest.scala
- Supertypes
- Self type
-
Manifest.type
ManifestFactory
defines factory methods for manifests.
ManifestFactory
defines factory methods for manifests. It is intended for use by the compiler and should not be used in client code.
Unlike Manifest
, this factory isn't annotated with a deprecation warning. This is done to prevent avalanches of deprecation warnings in the code that calls methods with manifests. Why so complicated? Read up the comments for ClassManifestFactory
.
Attributes
- Source
- Manifest.scala
- Supertypes
- Self type
-
ManifestFactory.type
Provides functions to encode and decode Scala symbolic names.
Provides functions to encode and decode Scala symbolic names. Also provides some constants.
Attributes
- Source
- NameTransformer.scala
- Supertypes
- Self type
-
NameTransformer.type
One of the branches of an scala.reflect.OptManifest.
One of the branches of an scala.reflect.OptManifest.
Attributes
- Source
- NoManifest.scala
- Supertypes
- Self type
-
NoManifest.type
A OptManifest[T]
is an optional scala.reflect.Manifest.
A OptManifest[T]
is an optional scala.reflect.Manifest.
It is either a Manifest
or the value NoManifest
.
Attributes
- Source
- OptManifest.scala
- Supertypes
- Known subtypes
-
trait ClassManifestDeprecatedApis[T]trait ClassTag[T]trait Manifest[T]class AnyValManifest[T]object NoManifest
A class that implements structural selections using Java reflection.
A class that implements structural selections using Java reflection.
It can be used as a supertrait of a class or be made available as an implicit conversion via reflectiveSelectable
.
In Scala.js, it is implemented using a separate Scala.js-specific mechanism, since Java reflection is not available.
Attributes
- Companion
- object
- Source
- Selectable.scala
- Supertypes
Attributes
- Companion
- trait
- Source
- Selectable.scala
- Supertypes
- Self type
-
Selectable.type
A TypeTest[S, T]
contains the logic needed to know at runtime if a value of type S
is an instance of T
.
A TypeTest[S, T]
contains the logic needed to know at runtime if a value of type S
is an instance of T
.
If a pattern match is performed on a term of type s: S
that is uncheckable with s.isInstanceOf[T]
and the pattern is one of the following forms:
t: T
t @ X()
whereX.unapply
takes an argument of typeT
then a given instance ofTypeTest[S, T]
is summoned and used to perform the test.
Attributes
- Companion
- object
- Source
- TypeTest.scala
- Supertypes
Deprecated classlikes
Attributes
- Deprecated
- true
- Source
- ClassManifestDeprecatedApis.scala
- Supertypes
- Known subtypes
- Self type
-
ClassTag[T]
Types
A shorhand for TypeTest[Any, T]
. A Typeable[T] contains the logic needed to know at runtime if a value can be downcasted to
T`.
A shorhand for TypeTest[Any, T]
. A Typeable[T] contains the logic needed to know at runtime if a value can be downcasted to
T`.
If a pattern match is performed on a term of type s: Any
that is uncheckable with s.isInstanceOf[T]
and the pattern are of the form:
t: T
t @ X()
where theX.unapply
has takes an argument of typeT
then a given instance ofTypeable[T]
(TypeTest[Any, T]
) is summoned and used to perform the test.
Attributes
- Source
- Typeable.scala
Deprecated types
A ClassManifest[T]
is an opaque descriptor for type T
.
A ClassManifest[T]
is an opaque descriptor for type T
. It is used by the compiler to preserve information necessary for instantiating Arrays
in those cases where the element type is unknown at compile time.
The type-relation operators make an effort to present a more accurate picture than can be realized with erased types, but they should not be relied upon to give correct answers. In particular they are likely to be wrong when variance is involved or when a subtype has a different number of type arguments than a supertype.
Attributes
- Deprecated
- true
- Source
- package.scala
Value members
Concrete methods
Attributes
- Source
- package.scala
Make a java reflection object accessible, if it is not already and it is possible to do so.
Make a java reflection object accessible, if it is not already and it is possible to do so. If a SecurityException is thrown in the attempt, it is caught and discarded.
Attributes
- Source
- package.scala
Deprecated fields
The object ClassManifest
defines factory methods for manifests.
The object ClassManifest
defines factory methods for manifests. It is intended for use by the compiler and should not be used in client code.
Attributes
- Deprecated
- true
- Source
- package.scala