Class scala.reflect.runtime.JavaUniverse

The API of Annotation instances. The main source of information about annotations is the scala.reflect.api.Annotations page.

An extractor class to create and pattern match with syntax Annotation(tpe, scalaArgs, javaArgs). Here, tpe is the annotation type, scalaArgs the payload of Scala annotations, and javaArgs the payload of Java annotations.

The API of Constant instances.

An extractor class to create and pattern match with syntax Constant(value) where value is the Scala value of the constant.

Expr wraps an abstract syntax tree and tags it with its type. The main source of information about exprs is the scala.reflect.api.Exprs page.

The API of FlagSet instances. The main source of information about flag sets is the scala.reflect.api.FlagSets page.

All possible values that can constitute flag sets. The main source of information about flag sets is the scala.reflect.api.FlagSets page.

Presence of an implicit value of this type in scope indicates that source compatibility with Scala 2.10 has been enabled.

The API of free term symbols. The main source of information about symbols is the Symbols page.

$SYMACCESSORS

The API of free type symbols. The main source of information about symbols is the Symbols page.

$SYMACCESSORS

This trait provides support for importers, a facility to migrate reflection artifacts between universes. Note: this trait should typically be used only rarely.

Reflection artifacts, such as Symbols and Types, are contained in Universes. Typically all processing happens within a single Universe (e.g. a compile-time macro Universe or a runtime reflection Universe), but sometimes there is a need to migrate artifacts from one Universe to another. For example, runtime compilation works by importing runtime reflection trees into a runtime compiler universe, compiling the importees and exporting the result back.

Reflection artifacts are firmly grounded in their Universes, which is reflected by the fact that types of artifacts from different universes are not compatible. By using Importers, however, they be imported from one universe into another. For example, to import foo.bar.Baz from the source Universe to the target Universe, an importer will first check whether the entire owner chain exists in the target Universe. If it does, then nothing else will be done. Otherwise, the importer will recreate the entire owner chain and will import the corresponding type signatures into the target Universe.

Since importers match Symbol tables of the source and the target Universes using plain string names, it is programmer's responsibility to make sure that imports don't distort semantics, e.g., that foo.bar.Baz in the source Universe means the same that foo.bar.Baz does in the target Universe.

Example

Here's how one might implement a macro that performs compile-time evaluation of its argument by using a runtime compiler to compile and evaluate a tree that belongs to a compile-time compiler:

def staticEval[T](x: T) = macro staticEval[T]

def staticEval[T](c: scala.reflect.macros.blackbox.Context)(x: c.Expr[T]) = {
  // creates a runtime reflection universe to host runtime compilation
  import scala.reflect.runtime.{universe => ru}
  val mirror = ru.runtimeMirror(c.libraryClassLoader)
  import scala.tools.reflect.ToolBox
  val toolBox = mirror.mkToolBox()

  // runtime reflection universe and compile-time macro universe are different
  // therefore an importer is needed to bridge them
  // currently mkImporter requires a cast to correctly assign the path-dependent types
  val importer0 = ru.internal.mkImporter(c.universe)
  val importer = importer0.asInstanceOf[ru.internal.Importer { val from: c.universe.type }]

  // the created importer is used to turn a compiler tree into a runtime compiler tree
  // both compilers use the same classpath, so semantics remains intact
  val imported = importer.importTree(tree)

  // after the tree is imported, it can be evaluated as usual
  val tree = toolBox.untypecheck(imported.duplicate)
  val valueOfX = toolBox.eval(imported).asInstanceOf[T]
  ...
}

Reflection API exhibits a tension inherent to experimental things: on the one hand we want it to grow into a beautiful and robust API, but on the other hand we have to deal with immaturity of underlying mechanisms by providing not very pretty solutions to enable important use cases.

In Scala 2.10, which was our first stab at reflection API, we didn't have a systematic approach to dealing with this tension, sometimes exposing too much of internals (e.g. Symbol.deSkolemize) and sometimes exposing too little (e.g. there's still no facility to change owners, to do typing transformations, etc). This resulted in certain confusion with some internal APIs living among public ones, scaring the newcomers, and some internal APIs only available via casting, which requires intimate knowledge of the compiler and breaks compatibility guarantees.

This led to creation of the internal API module for the reflection API, which provides advanced APIs necessary for macros that push boundaries of the state of the art, clearly demarcating them from the more or less straightforward rest and providing compatibility guarantees on par with the rest of the reflection API (full compatibility within minor releases, best effort towards backward compatibility within major releases, clear replacement path in case of rare incompatible changes in major releases).

The internal module itself (the value that implements InternalApi) isn't defined here, in scala.reflect.api.Universe, but is provided on per-implementation basis. Runtime API endpoint (scala.reflect.runtime.universe) provides universe.compat: InternalApi, whereas compile-time API endpoints (instances of scala.reflect.macros.Context) provide c.compat: ContextInternalApi, which extends InternalApi with additional universe-specific and context-specific functionality.

The API that all references support

An extractor class to create and pattern match with syntax ReferenceToBoxed(ident). This AST node does not have direct correspondence to Scala code, and is emitted by macros to reference capture vars directly without going through elem.

For example:

var x = ... fun { x }

Will emit:

Ident(x)

Which gets transformed to:

Select(Ident(x), "elem")

If ReferenceToBoxed were used instead of Ident, no transformation would be performed.

This is an internal implementation class.

A type class that defines a representation of T as a Tree.

A type class that defines a way to extract instance of T from a Tree.

A mirror that reflects the instance parts of a runtime class. See the overview page for details on how to use runtime reflection.

A mirror that reflects a field. See the overview page for details on how to use runtime reflection.

A mirror that reflects a runtime value. See the overview page for details on how to use runtime reflection.

A mirror that reflects a method. See the overview page for details on how to use runtime reflection.

A mirror that reflects a Scala object definition or the static parts of a runtime class. See the overview page for details on how to use runtime reflection.

A mirror that reflects instances and static classes. See the overview page for details on how to use runtime reflection.

Has no special methods. Is here to provides erased identity for RuntimeClass.

The API of a mirror for a reflective universe. See the overview page for details on how to use runtime reflection.

A mirror that reflects the instance or static parts of a runtime class. See the overview page for details on how to use runtime reflection.

The API of Name instances.

Has no special methods. Is here to provides erased identity for TermName.

An extractor class to create and pattern match with syntax TermName(s).

Has no special methods. Is here to provides erased identity for TypeName.

An extractor class to create and pattern match with syntax TypeName(s).

Implicit class that introduces q, tq, cq, pq and fq string interpolators that are also known as quasiquotes. With their help you can easily manipulate Scala reflection ASTs.

The API that all member scopes support

The API that all scopes support

Defines standard symbols (and types via its base trait).

Defines standard types.

Defines standard names, common for term and type names: These can be accessed via the nme and tpnme members.

Defines standard term names that can be accessed via the nme member.

Defines standard type names that can be accessed via the tpnme member.

The API of class symbols. The main source of information about symbols is the Symbols page.

Class Symbol defines isXXX test methods such as isPublic or isFinal, params and returnType methods for method symbols, baseClasses for class symbols and so on. Some of these methods don't make sense for certain subclasses of Symbol and return NoSymbol, Nil or other empty values.

The API of method symbols. The main source of information about symbols is the Symbols page.

Class Symbol defines isXXX test methods such as isPublic or isFinal, params and returnType methods for method symbols, baseClasses for class symbols and so on. Some of these methods don't make sense for certain subclasses of Symbol and return NoSymbol, Nil or other empty values.

The API of module symbols. The main source of information about symbols is the Symbols page.

Class Symbol defines isXXX test methods such as isPublic or isFinal, params and returnType methods for method symbols, baseClasses for class symbols and so on. Some of these methods don't make sense for certain subclasses of Symbol and return NoSymbol, Nil or other empty values.

The API of symbols. The main source of information about symbols is the Symbols page.

Class Symbol defines isXXX test methods such as isPublic or isFinal, params and returnType methods for method symbols, baseClasses for class symbols and so on. Some of these methods don't make sense for certain subclasses of Symbol and return NoSymbol, Nil or other empty values.

The API of term symbols. The main source of information about symbols is the Symbols page.

Class Symbol defines isXXX test methods such as isPublic or isFinal, params and returnType methods for method symbols, baseClasses for class symbols and so on. Some of these methods don't make sense for certain subclasses of Symbol and return NoSymbol, Nil or other empty values.

The API of type symbols. The main source of information about symbols is the Symbols page.

Class Symbol defines isXXX test methods such as isPublic or isFinal, params and returnType methods for method symbols, baseClasses for class symbols and so on. Some of these methods don't make sense for certain subclasses of Symbol and return NoSymbol, Nil or other empty values.

The API that all alternatives support

An extractor class to create and pattern match with syntax Alternative(trees). This AST node corresponds to the following Scala code:

pat1 | ... | patn

The API that all annotateds support

An extractor class to create and pattern match with syntax Annotated(annot, arg). This AST node corresponds to the following Scala code:

arg @annot // for types arg: @annot // for exprs

The API that all applied type trees support

An extractor class to create and pattern match with syntax AppliedTypeTree(tpt, args). This AST node corresponds to the following Scala code:

tpt[args]

Should only be used with tpt nodes which are types, i.e. which have isType returning true. Otherwise TypeApply should be used instead.

List[Int] as in val x: List[Int] = ??? // represented as AppliedTypeTree(Ident(<List>), List(TypeTree(<Int>)))

def foo[T] = ??? foo[Int] // represented as TypeApply(Ident(<foo>), List(TypeTree(<Int>)))

The API that all applies support

An extractor class to create and pattern match with syntax Apply(fun, args). This AST node corresponds to the following Scala code:

fun(args)

For instance:

fun[targs](args)

Is expressed as:

Apply(TypeApply(fun, targs), args)

The API that all assigns support

An extractor class to create and pattern match with syntax Assign(lhs, rhs). This AST node corresponds to the following Scala code:

lhs = rhs

The API that all assigns support

An extractor class to create and pattern match with syntax AssignOrNamedArg(lhs, rhs). This AST node corresponds to the following Scala code:

m.f(lhs = rhs)

@annotation(lhs = rhs)

The API that all binds support

An extractor class to create and pattern match with syntax Bind(name, body). This AST node corresponds to the following Scala code:

pat*

The API that all blocks support

An extractor class to create and pattern match with syntax Block(stats, expr). This AST node corresponds to the following Scala code:

{ stats; expr }

If the block is empty, the expr is set to Literal(Constant(())).

The API that all case defs support

An extractor class to create and pattern match with syntax CaseDef(pat, guard, body). This AST node corresponds to the following Scala code:

case pat if guard => body

If the guard is not present, the guard is set to EmptyTree. If the body is not specified, the body is set to Literal(Constant(()))

The API that all class defs support

An extractor class to create and pattern match with syntax ClassDef(mods, name, tparams, impl). This AST node corresponds to the following Scala code:

mods class name [tparams] impl

Where impl stands for:

extends parents { defs }

The API that all compound type trees support

An extractor class to create and pattern match with syntax CompoundTypeTree(templ). This AST node corresponds to the following Scala code:

parent1 with ... with parentN { refinement }

The API that all def defs support

An extractor class to create and pattern match with syntax DefDef(mods, name, tparams, vparamss, tpt, rhs). This AST node corresponds to the following Scala code:

mods def name[tparams](vparams_1)...(vparams_n): tpt = rhs

If the return type is not specified explicitly (i.e. is meant to be inferred), this is expressed by having tpt set to TypeTree() (but not to an EmptyTree!).

The API that all def trees support

The API that all existential type trees support

An extractor class to create and pattern match with syntax ExistentialTypeTree(tpt, whereClauses). This AST node corresponds to the following Scala code:

tpt forSome { whereClauses }

The API that all functions support

An extractor class to create and pattern match with syntax Function(vparams, body). This AST node corresponds to the following Scala code:

vparams => body

The symbol of a Function is a synthetic TermSymbol. It is the owner of the function's parameters.

The API that all applies support

The API that all idents support

An extractor class to create and pattern match with syntax Ident(qual, name). This AST node corresponds to the following Scala code:

name

Type checker converts idents that refer to enclosing fields or methods to selects. For example, name ==> this.name

The API that all ifs support

An extractor class to create and pattern match with syntax If(cond, thenp, elsep). This AST node corresponds to the following Scala code:

if (cond) thenp else elsep

If the alternative is not present, the elsep is set to Literal(Constant(())).

The API that all impl defs support

The API that all imports support

An extractor class to create and pattern match with syntax Import(expr, selectors). This AST node corresponds to the following Scala code:

import expr.{selectors}

Selectors are a list of ImportSelectors, which conceptually are pairs of names (from, to). The last (and maybe only name) may be a nme.WILDCARD. For instance:

import qual.{x, y => z, _}

Would be represented as:

Import(qual, List(("x", "x"), ("y", "z"), (WILDCARD, null)))

The symbol of an Import is an import symbol @see Symbol.newImport. It's used primarily as a marker to check that the import has been typechecked.

The API that all import selectors support

An extractor class to create and pattern match with syntax ImportSelector(name:, namePos, rename, renamePos). This is not an AST node, it is used as a part of the Import node.

The API that all label defs support

An extractor class to create and pattern match with syntax LabelDef(name, params, rhs).

This AST node does not have direct correspondence to Scala code. It is used for tailcalls and like. For example, while/do are desugared to label defs as follows:

while (cond) body ==> LabelDef($L, List(), if (cond) { body; L$() } else ())

do body while (cond) ==> LabelDef($L, List(), body; if (cond) L$() else ())

The API that all literals support

An extractor class to create and pattern match with syntax Literal(value). This AST node corresponds to the following Scala code:

value

The API that all matches support

An extractor class to create and pattern match with syntax Match(selector, cases). This AST node corresponds to the following Scala code:

selector match { cases }

Match is also used in pattern matching assignments like val (foo, bar) = baz.

The API that all member defs support

The API that all Modifiers support

An extractor class to create and pattern match with syntax Modifiers(flags, privateWithin, annotations). Modifiers encapsulate flags, visibility annotations and Scala annotations for member definitions.

The API that all module defs support

An extractor class to create and pattern match with syntax ModuleDef(mods, name, impl). This AST node corresponds to the following Scala code:

mods object name impl

Where impl stands for:

extends parents { defs }

The API that all name trees support

The API that all news support

An extractor class to create and pattern match with syntax New(tpt). This AST node corresponds to the following Scala code:

new T

This node always occurs in the following context:

(new tpt).<init>[targs](args)

For example, an AST representation of:

new Example[Int](2)(3)

is the following code:

Apply( Apply( TypeApply( Select(New(TypeTree(typeOf[Example])), nme.CONSTRUCTOR) TypeTree(typeOf[Int])), List(Literal(Constant(2)))), List(Literal(Constant(3))))

The API that all package defs support

An extractor class to create and pattern match with syntax PackageDef(pid, stats). This AST node corresponds to the following Scala code:

package pid { stats }

The API that all ref trees support

An extractor class to create and pattern match with syntax RefTree(qual, name). This AST node corresponds to either Ident, Select or SelectFromTypeTree.

The API that all returns support

An extractor class to create and pattern match with syntax Return(expr). This AST node corresponds to the following Scala code:

return expr

The symbol of a Return node is the enclosing method.

The API that all selects support

An extractor class to create and pattern match with syntax Select(qual, name). This AST node corresponds to the following Scala code:

qualifier.selector

Should only be used with qualifier nodes which are terms, i.e. which have isTerm returning true. Otherwise SelectFromTypeTree should be used instead.

foo.Bar // represented as Select(Ident(<foo>), <Bar>) Foo#Bar // represented as SelectFromTypeTree(Ident(<Foo>), <Bar>)

The API that all selects from type trees support

An extractor class to create and pattern match with syntax SelectFromTypeTree(qualifier, name). This AST node corresponds to the following Scala code:

qualifier # selector

Note: a path-dependent type p.T is expressed as p.type # T

Should only be used with qualifier nodes which are types, i.e. which have isType returning true. Otherwise Select should be used instead.

Foo#Bar // represented as SelectFromTypeTree(Ident(<Foo>), <Bar>) foo.Bar // represented as Select(Ident(<foo>), <Bar>)

The API that all singleton type trees support

An extractor class to create and pattern match with syntax SingletonTypeTree(ref). This AST node corresponds to the following Scala code:

ref.type

The API that all stars support

An extractor class to create and pattern match with syntax Star(elem). This AST node corresponds to the following Scala code:

pat*

The API that all supers support

An extractor class to create and pattern match with syntax Super(qual, mix). This AST node corresponds to the following Scala code:

C.super[M]

Which is represented as:

Super(This(C), M)

If mix is empty, it is tpnme.EMPTY.

The symbol of a Super is the class _from_ which the super reference is made. For instance in C.super(...), it would be C.

The API that all sym trees support

The API that all templates support

An extractor class to create and pattern match with syntax Template(parents, self, body). This AST node corresponds to the following Scala code:

extends parents { self => body }

In case when the self-type annotation is missing, it is represented as an empty value definition with nme.WILDCARD as name and NoType as type.

The symbol of a template is a local dummy. @see Symbol.newLocalDummy The owner of the local dummy is the enclosing trait or class. The local dummy is itself the owner of any local blocks. For example:

class C { def foo { // owner is C def bar // owner is local dummy } }

The API that all term trees support

The API that all thises support

An extractor class to create and pattern match with syntax This(qual). This AST node corresponds to the following Scala code:

qual.this

The symbol of a This is the class to which the this refers. For instance in C.this, it would be C.

The API that all tries support

An extractor class to create and pattern match with syntax Throw(expr). This AST node corresponds to the following Scala code:

throw expr

A class that implement a default tree transformation strategy: breadth-first component-wise cloning.

A class that implement a default tree traversal strategy: breadth-first component-wise.

The API that all trees support. The main source of information about trees is the scala.reflect.api.Trees page.

The API of a tree copier.

The API that all tries support

An extractor class to create and pattern match with syntax Try(block, catches, finalizer). This AST node corresponds to the following Scala code:

try block catch { catches } finally finalizer

If the finalizer is not present, the finalizer is set to EmptyTree.

The API that all typ trees support

The API that all type applies support

An extractor class to create and pattern match with syntax TypeApply(fun, args). This AST node corresponds to the following Scala code:

fun[args]

Should only be used with fun nodes which are terms, i.e. which have isTerm returning true. Otherwise AppliedTypeTree should be used instead.

def foo[T] = ??? foo[Int] // represented as TypeApply(Ident(<foo>), List(TypeTree(<Int>)))

List[Int] as in val x: List[Int] = ??? // represented as AppliedTypeTree(Ident(<List>), List(TypeTree(<Int>)))

The API that all type bound trees support

An extractor class to create and pattern match with syntax TypeBoundsTree(lo, hi). This AST node corresponds to the following Scala code:

>: lo <: hi

The API that all type defs support

An extractor class to create and pattern match with syntax TypeDef(mods, name, tparams, rhs). This AST node corresponds to the following Scala code:

mods type name[tparams] = rhs

mods type name[tparams] >: lo <: hi

First usage illustrates TypeDefs representing type aliases and type parameters. Second usage illustrates TypeDefs representing abstract types, where lo and hi are both TypeBoundsTrees and Modifier.deferred is set in mods.

The API that all type trees support

An extractor class to create and pattern match with syntax TypeTree(). This AST node does not have direct correspondence to Scala code, and is emitted by everywhere when we want to wrap a Type in a Tree.

The API that all typeds support

An extractor class to create and pattern match with syntax Typed(expr, tpt). This AST node corresponds to the following Scala code:

expr: tpt

The API that all unapplies support

An extractor class to create and pattern match with syntax UnApply(fun, args). This AST node does not have direct correspondence to Scala code, and is introduced when typechecking pattern matches and try blocks.

The API that all val defs support

An extractor class to create and pattern match with syntax ValDef(mods, name, tpt, rhs). This AST node corresponds to any of the following Scala code:

mods val name: tpt = rhs

mods var name: tpt = rhs

mods name: tpt = rhs // in signatures of function and method definitions

self: Bar => // self-types

If the type of a value is not specified explicitly (i.e. is meant to be inferred), this is expressed by having tpt set to TypeTree() (but not to an EmptyTree!).

The API that all val defs and def defs support

A TypeTag is a scala.reflect.api.TypeTags#WeakTypeTag with the additional static guarantee that all type references are concrete, i.e. it does not contain any references to unresolved type parameters or abstract types.

If an implicit value of type WeakTypeTag[T] is required, the compiler will create one, and the reflective representation of T can be accessed via the tpe field. Components of T can be references to type parameters or abstract types. Note that WeakTypeTag makes an effort to be as concrete as possible, i.e. if TypeTags are available for the referenced type arguments or abstract types, they are used to embed the concrete types into the WeakTypeTag. Otherwise the WeakTypeTag will contain a reference to an abstract type. This behavior can be useful, when one expects T to be perhaps be partially abstract, but requires special care to handle this case. However, if T is expected to be fully known, use scala.reflect.api.TypeTags#TypeTag instead, which statically guarantees this property.

For more information about TypeTags, see the Reflection Guide: TypeTags

The API that all annotated types support. The main source of information about types is the scala.reflect.api.Types page.

An extractor class to create and pattern match with syntax AnnotatedType(annotations, underlying). Here, annotations are the annotations decorating the underlying type underlying. selfSym is a symbol representing the annotated type itself.

The API that all this types support. The main source of information about types is the scala.reflect.api.Types page.

An extractor class to create and pattern match with syntax BoundedWildcardTypeExtractor(bounds) with bounds denoting the type bounds.

The API that all class info types support. The main source of information about types is the scala.reflect.api.Types page.

An extractor class to create and pattern match with syntax ClassInfo(parents, decls, clazz) Here, parents is the list of parent types of the class, decls is the scope containing all declarations in the class, and clazz is the symbol of the class itself.

Has no special methods. Is here to provides erased identity for CompoundType.

The API that all constant types support. The main source of information about types is the scala.reflect.api.Types page.

An extractor class to create and pattern match with syntax ConstantType(constant) Here, constant is the constant value represented by the type.

The API that all existential types support. The main source of information about types is the scala.reflect.api.Types page.

An extractor class to create and pattern match with syntax ExistentialType(quantified, underlying). Here, quantified are the type variables bound by the existential type and underlying is the type that's existentially quantified.

The API that all method types support. The main source of information about types is the scala.reflect.api.Types page.

An extractor class to create and pattern match with syntax MethodType(params, restpe) Here, params is a potentially empty list of parameter symbols of the method, and restpe is the result type of the method. If the method is curried, restpe would be another MethodType. Note: MethodType(Nil, Int) would be the type of a method defined with an empty parameter list.

def f(): Int

If the method is completely parameterless, as in

def f: Int

its type is a NullaryMethodType.

The API that all nullary method types support. The main source of information about types is the scala.reflect.api.Types page.

An extractor class to create and pattern match with syntax NullaryMethodType(resultType). Here, resultType is the result type of the parameterless method.

The API that all polymorphic types support. The main source of information about types is the scala.reflect.api.Types page.

An extractor class to create and pattern match with syntax PolyType(typeParams, resultType). Here, typeParams are the type parameters of the method and resultType is the type signature following the type parameters.

The API that all refined types support. The main source of information about types is the scala.reflect.api.Types page.

An extractor class to create and pattern match with syntax RefinedType(parents, decls) Here, parents is the list of parent types of the class, and decls is the scope containing all declarations in the class.

The API that all single types support. The main source of information about types is the scala.reflect.api.Types page.

An extractor class to create and pattern match with syntax SingleType(pre, sym) Here, pre is the prefix of the single-type, and sym is the stable value symbol referred to by the single-type.

Has no special methods. Is here to provides erased identity for SingletonType.

The API that all super types support. The main source of information about types is the scala.reflect.api.Types page.

An extractor class to create and pattern match with syntax SingleType(thistpe, supertpe)

The API that all this types support. The main source of information about types is the scala.reflect.api.Types page.

An extractor class to create and pattern match with syntax ThisType(sym) where sym is the class prefix of the this type.

The API of types. The main source of information about types is the scala.reflect.api.Types page.

The API that all type bounds support. The main source of information about types is the scala.reflect.api.Types page.

An extractor class to create and pattern match with syntax TypeBound(lower, upper) Here, lower is the lower bound of the TypeBounds pair, and upper is the upper bound.

The API that all type refs support. The main source of information about types is the scala.reflect.api.Types page.

An extractor class to create and pattern match with syntax TypeRef(pre, sym, args) Here, pre is the prefix of the type reference, sym is the symbol referred to by the type reference, and args is a possible empty list of type arguments.

<invalid inheritdoc annotation>

Let's say you have a type definition

type T <: Number

and tsym is the symbol corresponding to T. Then

tsym is an instance of AbstractTypeSymbol
tsym.info == TypeBounds(Nothing, Number)
tsym.tpe  == TypeRef(NoPrefix, T, List())

A type carrying some annotations. Created by the typechecker when eliminating Annotated trees (see typedAnnotated).

An additional checker for annotations on types. Typically these are registered by compiler plugins with the addAnnotationChecker method.

Typed information about an annotation. It can be attached to either a symbol or an annotated type.

Annotations are written to the classfile as Java annotations if atp conforms to ClassfileAnnotation (the classfile parser adds this interface to any Java annotation class).

Annotations are pickled (written to scala symtab attribute in the classfile) if atp inherits form StaticAnnotation.

args stores arguments to Scala annotations, represented as typed trees. Note that these trees are not transformed by any phases following the type-checker.

assocs stores arguments to classfile annotations as name-value pairs.

A class remembering a type instantiation for some a set of overloaded polymorphic symbols. Not used after phase typer.

Precondition: params.length == typeArgs.length > 0 (enforced structurally).

Represents an array of classfile annotation arguments

The constructor/extractor for ArrayArgument instances.

An array of expressions. This AST node needs to be translated in backend. It is used to pass arguments to vararg arguments. Introduced by compiler phase uncurry.

This AST node does not have direct correspondence to Scala code, and is used to pass arguments to vararg arguments. For instance:

printf("%s%d", foo, 42)

Is translated to after compiler phase uncurry to:

Apply( Ident("printf"), Literal("%s%d"), ArrayValue(<Any>, List(Ident("foo"), Literal(42))))

A map to compute the asSeenFrom method.

Common code between reflect-internal Symbol and Tree related to Attachments.

Note: constructor is protected to force everyone to use the factory method newBaseTypeSeq instead. This is necessary because when run from reflection every base type sequence needs to have a SynchronizedBaseTypeSeq as mixin.

BoundedWildcardTypes, used only during type inference, are created in two places that I can find:

If the expected type of an expression is an existential type, its hidden symbols are replaced with bounded wildcards. 2. When an implicit conversion is being sought based in part on the name of a method in the converted type, a HasMethodMatching type is created: a MethodType with parameters typed as BoundedWildcardTypes.

A class representing a class info

A class for class symbols

Arguments to classfile annotations (which are written to bytecode as java annotations) are either:

constantsarrays of constantsor nested classfile annotations

A map to implement the collect method.

A common base class for intersection types and class types

Stores the trees that give rise to a refined type to be used in reification. Unfortunately typed CompoundTypeTree is lacking essential info, and the reifier cannot use CompoundTypeTree.tpe. Therefore we need this hack (see Reshape.toPreTyperTypeTree for a detailed explanation).

A class representing a constant type.

A map to implement the contains method.

An exception for cyclic references of symbol definitions

A temporary type representing the erasure of a user-defined value type. Created during phase erasure, eliminated again in posterasure.

scala/bug#6385 Erasure's creation of bridges considers method signatures exitingErasure, which contain ErasedValueType-s. In order to correctly consider the overriding and overridden signatures as equivalent in run/t6385.scala, it is critical that this type contains the erasure of the wrapped type, rather than the unerased type of the value class itself, as was originally done.

The error scope.

Used by existentialAbstraction.

A map to implement the filter method.

A map to implement the filter method.

A marker trait representing an as-yet unevaluated type which doesn't assign flags to the underlying symbol.

A marker trait representing an as-yet unevaluated type which assigns flags to the underlying symbol.

Precondition: params.nonEmpty. (args.nonEmpty enforced structurally.)

Attachment that knows how to import itself into another universe.

Note: This map is needed even for non-dependent method types, despite what the name might imply.

The API of a mirror for a reflective universe

This should be the first trait in the linearization.

The data structure describing the kind of a given type.

Proper types are represented using ProperTypeKind.

Type constructors are represented using TypeConKind.

Symbol annotations parsed in Namer (typeCompleter of definitions) have to be lazy (#1782)

The type completer for packages.

A class representing an as-yet unevaluated type.

Represents a compile-time Constant (Boolean, Byte, Short, Char, Int, Long, Float, Double, String, java.lang.Class or an instance of a Java enumeration value).

The constructor/extractor for LiteralArgument instances.

A locator for trees with given positions. Given a position pos, locator.apply returns the smallest tree that encloses pos.

A throwable signalling a malformed type

A class for method symbols

A class representing a method type with parameters. Note that a parameterless method is represented by a NullaryMethodType:

def m(): Int MethodType(Nil, Int) def m: Int NullaryMethodType(Int)

In runtime reflection universes, mirrors are JavaMirrors.

A class for module class symbols Note: Not all module classes are of this type; when unpickled, we get plain class symbols!

A class for module symbols

The name class. TODO - resolve schizophrenia regarding whether to treat Names as Strings or Strings as Names. Give names the key functions the absence of which make people want Strings all the time.

An ADT to represent the results of symbol name lookups.

FIXME: This is a good example of something which is pure "value class" but cannot reap the benefits because an (unused) $outer pointer so it is not single-field.

A class representing types with a name. When an application uses named arguments, the named argument types for calling isApplicable are represented as NamedType.

Represents a nested classfile annotation

The constructor/extractor for NestedArgument instances.

An object representing a missing symbol

A class containing the alternatives and type prefix of an overloaded symbol. Not used after phase typer.

A period is an ordinal number for a phase in a run. Phases in later runs have higher periods than phases in earlier runs. Later phases have higher periods than earlier phases in the same run.

Attachment that doesn't contain any reflection artifacts and can be imported as-is.

A type function or the type of a polymorphic value (and thus of kind *).

Before the introduction of NullaryMethodType, a polymorphic nullary method (e.g, def isInstanceOf[T]: Boolean) used to be typed as PolyType(tps, restpe), and a monomorphic one as PolyType(Nil, restpe) This is now: PolyType(tps, NullaryMethodType(restpe)) and NullaryMethodType(restpe) by symmetry to MethodTypes: PolyType(tps, MethodType(params, restpe)) and MethodType(params, restpe)

Thus, a PolyType(tps, TypeRef(...)) unambiguously indicates a type function (which results from eta-expanding a type constructor alias). Similarly, PolyType(tps, ClassInfoType(...)) is a type constructor.

A polytype is of kind * iff its resultType is a (nullary) method type.

Defines a universe-specific notion of positions. The main documentation entry about positions is located at scala.reflect.api.Position.

An exception for cyclic references from which we can recover

A class representing intersection types with refinements of the form <parents_0> with ... with <parents_n> { decls } Cannot be created directly; one should always use refinedType for creation.

As with NamedType, used only when calling isApplicable. Records that the application has a wildcard star (aka _*) at the end of it.

A proxy for a type (identified by field underlying) that forwards most operations to it. Every operation that is overridden for some kind of types is forwarded here. Some operations are rewrapped again.

An ordinal number for compiler runs. First run has number 1.

In runtime reflection universes, runtime representation of a class is java.lang.Class.

Attached to a Function node during type checking when the expected type is a SAM type (and not a built-in FunctionN).

Ideally, we'd move to Dotty's Closure AST, which tracks the environment, the lifted method that has the implementation, and the target type. For backwards compatibility, an attachment is the best we can do right now.

A specific annotation argument that encodes an array of bytes as an array of Long. The type of the argument declared in the annotation must be String. This specialised class is used to encode Scala signatures for reasons of efficiency, both in term of class-file size and in term of compiler performance. Details about the storage format of pickles at the bytecode level (classfile annotations) can be found in SIP-10.

Note: constructor is protected to force everyone to use the factory methods newScope or newNestedScope instead. This is necessary because when run from reflection every scope needs to have a SynchronizedScope as mixin.

A proxy for a type (identified by field underlying) that forwards most operations to it (for exceptions, see WrappingProxy, which forwards even more operations). every operation that is overridden for some kind of types should be forwarded.

A class for singleton types of the form <prefix>.<sym.name>.type. Cannot be created directly; one should always use singleType for creation.

A base class for types that represent a single value (single-types and this-types).

A base class for types that defer some operations to their immediate supertype.

Untyped list of subpatterns attached to selector dummy.

A base class to compute all substitutions

A map to implement the substSym method.

A map to implement the substThis method.

A map to implement the subst method.

The class for all symbols

A name that contains no operator chars nor dollar signs. TODO - see if it's any faster to do something along these lines. Cute: now that exhaustivity kind of works, the mere presence of this trait causes TermName and TypeName to stop being exhaustive. Commented out.

A class for term symbols

Substitute clazz.this with to. to must be an attributed tree.

A class for this-types of the form <sym>.this.type

The standard completer for top-level classes

The type of standard (lazy) tree copiers.

A transformer that replaces tree from with tree to in a given tree

Substitute symbols in from with symbols in to. Returns a new tree using the new symbols and whose Ident and Select nodes are name-consistent with the new symbols.

Note: This is currently a destructive operation on the original Tree. Trees currently assigned a symbol in from will be assigned the new symbols without copying, and trees that define symbols with an info that refer a symbol in from will have a new type assigned.

The base class for all types

A class for the bounds of abstract types and type parameters

A class expressing upper and lower bounds constraints of type variables, as well as their instantiations.

A throwable signalling a type error

A prototype for mapping a function over all possible types

An attachment carrying information between uncurry and erasure

A class for named types of the form <prefix>.<sym.name>[args] Cannot be created directly; one should always use typeRef for creation. (@M: Otherwise hashing breaks)

A class for type parameters viewed from inside their scopes

A class of type symbols. Alias and abstract types are direct instances of this class. Classes are instances of a subclass.

A class representing a type variable: not used after phase typer.

A higher-kinded TypeVar has params (Symbols) and typeArgs (Types). A TypeVar with nonEmpty typeArgs can only be instantiated by a higher-kinded type that can be applied to those args. A TypeVar is much like a TypeRef, except it has special logic for equality and subtyping.

Precondition for this class, enforced structurally: args.isEmpty && params.isEmpty.

Tracks the classes currently under construction during a transform

A type that can be passed to unique(..) and be stored in the uniques map.

Used in Refchecks. TODO - eliminate duplication with varianceInType

API of ArrayArgument instances. The main source of information about annotations is the scala.reflect.api.Annotations page.

An extractor class to create and pattern match with syntax ArrayArgument(args) where args is the argument array.

Has no special methods. Is here to provides erased identity for CompoundType.

The API of LiteralArgument instances. The main source of information about annotations is the scala.reflect.api.Annotations page.

An extractor class to create and pattern match with syntax LiteralArgument(value) where value is the constant argument.

API of NestedArgument instances. The main source of information about annotations is the scala.reflect.api.Annotations page.

An extractor class to create and pattern match with syntax NestedArgument(annotation) where annotation is the nested annotation.

The type of compilation units.

Compilation unit describes a unit of work of the compilation run. It provides such information as file name, textual representation of the unit and the underlying AST.

The type of compilation runs.

Compilation run uniquely identifies current invocation of the compiler (e.g. can be used to implement per-run caches for macros) and provides access to units of work of the invocation (currently processed unit of work and the list of all units).