scala3-compiler-bootstrapped/dotty.tools.dotc.core/Denotations

Denotations

object Denotations

Denotations represent the meaning of symbols and named types. The following diagram shows how the principal types of denotations and their denoting entities relate to each other. Lines ending in a down-arrow v are member methods. The two methods shown in the diagram are "symbol" and "deref". Both methods are parameterized by the current context, and are effectively indexed by current period.

Lines ending in a horizontal line mean subtyping (right is a subtype of left).

NamedType | Symbol---------ClassSymbol | | | | denot | denot | denot v v v Denotation-+-----SingleDenotation-+------SymDenotation-+----ClassDenotation | | +-----MultiDenotation | | +--UniqueRefDenotation +--JointRefDenotation

Here's a short summary of the classes in this diagram.

NamedType A type consisting of a prefix type and a name, with fields prefix: Type name: Name It has two subtypes: TermRef and TypeRef Symbol A label for a definition or declaration in one compiler run ClassSymbol A symbol representing a class Denotation The meaning of a named type or symbol during a period MultiDenotation A denotation representing several overloaded members SingleDenotation A denotation representing a non-overloaded member or definition, with main fields symbol: Symbol info: Type UniqueRefDenotation A denotation referring to a single definition with some member type JointRefDenotation A denotation referring to a member that could resolve to several definitions SymDenotation A denotation representing a single definition with its original type, with main fields name: Name owner: Symbol flags: Flags privateWithin: Symbol annotations: List[Annotation] ClassDenotation A denotation representing a single class definition.

class Object
trait Matchable
class Any

Type members

Classlikes

final case class DenotUnion(denot1: PreDenotation, denot2: PreDenotation) extends MultiPreDenotation
abstract class Denotation(val symbol: Symbol, var myInfo: Type) extends PreDenotation with Showable

A denotation is the result of resolving a name (either simple identifier or select) during a given period.

A denotation is the result of resolving a name (either simple identifier or select) during a given period.

Denotations can be combined with & and |. & is conjunction, | is disjunction.

& will create an overloaded denotation from two non-overloaded denotations if their signatures differ. Analogously | of two denotations with different signatures will give an empty denotation NoDenotation.

A denotation might refer to NoSymbol. This is the case if the denotation was produced from a disjunction of two denotations with different symbols and there was no common symbol in a superclass that could substitute for both symbols. Here is an example:

Say, we have:

class A { def f: A } class B { def f: B } val x: A | B = if (test) new A else new B val y = x.f

Then the denotation of y is SingleDenotation(NoSymbol, A | B).

Value Params
symbol

The referencing symbol, or NoSymbol is none exists

class ErrorDenotation(using `x$1`: Context) extends NonSymSingleDenotation
class JointRefDenotation(symbol: Symbol, initInfo: Type, initValidFor: Period, prefix: Type, val isRefinedMethod: Boolean) extends NonSymSingleDenotation
case class MissingRef(owner: SingleDenotation, name: Name)(using `x$3`: Context) extends ErrorDenotation

An error denotation that provides more info about the missing reference. Produced by staticRef, consumed by requiredSymbol.

An error denotation that provides more info about the missing reference. Produced by staticRef, consumed by requiredSymbol.

case class MultiDenotation(denot1: Denotation, denot2: Denotation) extends Denotation with MultiPreDenotation

An overloaded denotation consisting of the alternatives of both given denotations.

An overloaded denotation consisting of the alternatives of both given denotations.

trait MultiPreDenotation extends PreDenotation
case class NoQualifyingRef(alts: List[SingleDenotation])(using `x$2`: Context) extends ErrorDenotation

An error denotation that provides more info about alternatives that were found but that do not qualify. Produced by staticRef, consumed by requiredSymbol.

An error denotation that provides more info about alternatives that were found but that do not qualify. Produced by staticRef, consumed by requiredSymbol.

abstract class NonSymSingleDenotation(symbol: Symbol, initInfo: Type, val prefix: Type) extends SingleDenotation
abstract class PreDenotation

A PreDenotation represents a group of single denotations or a single multi-denotation It is used as an optimization to avoid forming MultiDenotations too eagerly.

A PreDenotation represents a group of single denotations or a single multi-denotation It is used as an optimization to avoid forming MultiDenotations too eagerly.

abstract class SingleDenotation(symbol: Symbol, initInfo: Type) extends Denotation

A non-overloaded denotation

A non-overloaded denotation

class StaleSymbol(msg: => String) extends Exception

An exception for accessing symbols that are no longer valid in current run

An exception for accessing symbols that are no longer valid in current run

class UniqueRefDenotation(symbol: Symbol, initInfo: Type, initValidFor: Period, prefix: Type) extends NonSymSingleDenotation

Value members

Concrete methods

def infoMeet(tp1: Type, tp2: Type, safeIntersection: Boolean)(using Context): Type

Normally, tp1 & tp2, with extra care taken to return tp1 or tp2 directly if that's a valid answer. Special cases for matching methods and classes, with the possibility of returning NoType. Special handling of ExprTypes, where mixed intersections widen the ExprType away.

Normally, tp1 & tp2, with extra care taken to return tp1 or tp2 directly if that's a valid answer. Special cases for matching methods and classes, with the possibility of returning NoType. Special handling of ExprTypes, where mixed intersections widen the ExprType away.

def isDoubleDef(sym1: Symbol, sym2: Symbol)(using Context): Boolean

A double definition

A double definition

def missingHook(owner: Symbol, name: Name)(using Context): Symbol

If we are looking for a non-existing term name in a package, assume it is a package for which we do not have a directory and enter it.

If we are looking for a non-existing term name in a package, assume it is a package for which we do not have a directory and enter it.

def staticRef(path: Name, generateStubs: Boolean, isPackage: Boolean)(using Context): Denotation

The current denotation of the static reference given by path, or a MissingRef or NoQualifyingRef instance, if it does not exist. if generateStubs is set, generates stubs for missing top-level symbols

The current denotation of the static reference given by path, or a MissingRef or NoQualifyingRef instance, if it does not exist. if generateStubs is set, generates stubs for missing top-level symbols

Implicits

Implicits