diff options
Diffstat (limited to 'src/library')
| -rw-r--r-- | src/library/scala/reflect/package.scala | 52 |
1 files changed, 27 insertions, 25 deletions
diff --git a/src/library/scala/reflect/package.scala b/src/library/scala/reflect/package.scala index 046491ae10..8b411d0dca 100644 --- a/src/library/scala/reflect/package.scala +++ b/src/library/scala/reflect/package.scala @@ -3,37 +3,37 @@ package scala /** * The base package of Scala's reflection library. * - * The reflection library is structured according to the 'cake pattern'. The base layer + * The reflection library is structured according to the 'cake pattern'. The base layer * resides in package [[scala.reflect.base]] and defines an interface to the following main types: - * + * * - [[scala.reflect.base.Types#Type Types]] represent types * - [[scala.reflect.base.Symbols#Symbol Symbols]] represent definitions * - [[scala.reflect.base.Trees#Tree Trees]] represent abstract syntax trees * - [[scala.reflect.base.Names#Name Names]] represent term and type names * - [[scala.reflect.base.Annotations#Annotation Annotations]] represent annotations * - [[scala.reflect.base.Positions#Position Positions]] represent source positions of tree nodes - * - [[scala.reflect.base.FlagSets#FlagSet FlagSet]] represent sets of flags that apply to symbols and + * - [[scala.reflect.base.FlagSets#FlagSet FlagSet]] represent sets of flags that apply to symbols and * definition trees - * - [[scala.reflect.base.Constants#Constant Constants]] represent compile-time constants. + * - [[scala.reflect.base.Constants#Constant Constants]] represent compile-time constants. * - * Each of these types are defined in their own enclosing traits, which are ultimately all inherited by class + * Each of these types are defined in their own enclosing traits, which are ultimately all inherited by class * [[scala.reflect.base.Universe Universe]]. The base universe defines a minimal interface to the above types. - * Universes that provide additional functionality such as deeper introspection or runtime code generation, + * Universes that provide additional functionality such as deeper introspection or runtime code generation, * are defined in packages [[scala.reflect.api]] and `scala.tools.reflect`. * - * The cake pattern employed here requires to write certain Scala idioms with more indirections that usual. + * The cake pattern employed here requires to write certain Scala idioms with more indirections that usual. * What follows is a description of these indirections, which will help to navigate the Scaladocs easily. * - * For instance, consider the base type of all abstract syntax trees: [[scala.reflect.base.Trees#Tree]]. - * This type is not a class but is abstract and has an upper bound of [[scala.reflect.base.Trees#TreeBase]], - * which is a class defining the minimal base interface for all trees. + * For instance, consider the base type of all abstract syntax trees: [[scala.reflect.base.Trees#Tree]]. + * This type is not a class but is abstract and has an upper bound of [[scala.reflect.base.Trees#TreeBase]], + * which is a class defining the minimal base interface for all trees. * - * For a more interesting tree type, consider [[scala.reflect.base.Trees#If]] representing if-expressions. - * It does not come with a class `IfBase`, since it does not add anything to the interface of its upper - * bound `TermTree`. However, it is defined next to a value `If` of type [[scala.reflect.base.Trees#IfExtractor]]. - * This value serves as the companion object defining a factory method `apply` and a corresponding `unapply` + * For a more interesting tree type, consider [[scala.reflect.base.Trees#If]] representing if-expressions. + * It does not come with a class `IfBase`, since it does not add anything to the interface of its upper + * bound `TermTree`. However, it is defined next to a value `If` of type [[scala.reflect.base.Trees#IfExtractor]]. + * This value serves as the companion object defining a factory method `apply` and a corresponding `unapply` * for pattern matching. - * + * * {{{ * import scala.reflect.runtime.universe._ * val cond = reify{ condition }.tree // <- just some tree representing a condition @@ -41,32 +41,32 @@ package scala * val other = Literal(Constant(2)) * val iftree = If(cond,body,other) * }}} - * + * * is equivalent to - * + * * {{{ * import scala.reflect.runtime.universe._ * val iftree = reify{ if( condition ) 1 else 2 }.tree * }}} * * and can be pattern matched as - * + * * {{{ * iftree match { case If(cond,body,other) => ... } * }}} - * - * Moreover, there is an implicit value [[scala.reflect.base.Trees#IfTag]] of type + * + * Moreover, there is an implicit value [[scala.reflect.base.Trees#IfTag]] of type * `ClassTag[If]` that is used by the Scala compiler so that we can indeed pattern match on `If`: * {{{ * iftree match { case _:If => ... } - * }}} + * }}} * Without the given implicit value, this pattern match would raise an "unchecked" warning at compile time * since `If` is an abstract type that gets erased at runtime. See [[scala.reflect.ClassTag]] for details. * - * To summarize: each tree type `X` (and similarly for other types such as `Type` or `Symbol`) is represented - * by an abstract type `X`, optionally together with a class `XBase` that defines `X`'s' interface. - * `X`'s companion object, if it exists, is represented by a value `X` that is of type `XExtractor`. - * Moreover, for each type `X`, there is a value `XTag` of type `ClassTag[X]` that allows to pattern match + * To summarize: each tree type `X` (and similarly for other types such as `Type` or `Symbol`) is represented + * by an abstract type `X`, optionally together with a class `XBase` that defines `X`'s' interface. + * `X`'s companion object, if it exists, is represented by a value `X` that is of type `XExtractor`. + * Moreover, for each type `X`, there is a value `XTag` of type `ClassTag[X]` that allows to pattern match * on `X`. */ package object reflect { @@ -113,6 +113,8 @@ package object reflect { def classTag[T](implicit ctag: ClassTag[T]) = ctag // typeTag incantation is defined inside scala.reflect.basis and scala.reflect.runtime.universe + private[scala] def materializeClassTag[T](u: base.Universe): ClassTag[T] = ??? // macro + // ClassTag class is defined in ClassTag.scala type TypeTag[T] = scala.reflect.basis.TypeTag[T] |