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scala3-compiler-bootstrapped/dotty.tools/dotty.tools.dotc/dotty.tools.dotc.cc/Capabilities/Reach

Reach

dotty.tools.dotc.cc.Capabilities.Reach
case class Reach(underlying: ObjectCapability) extends DerivedCapability

If x is a capability, its reach capability x*. x* stands for all capabilities reachable through x. We have {x} <: {x*} <: dcs(x)} where the deep capture set dcs(x) of x is the union of all capture sets that appear in covariant position in the type of x. If x and y are different variables then {x*} and {y*} are unrelated.

Reach capabilities cannot wrap read-only capabilities or maybe capabilities. We have (x?).reach = (x.reach)? (x.rd).reach = (x.reach).rd (x.only[T]).reach = (x*).only[T]

Attributes

Graph
Supertypes
trait Serializable
trait Product
trait Equals
trait Capability
trait Showable
class Object
trait Matchable
class Any
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Members list

Value members

Inherited methods

final def adjustOwner(owner: Symbol)(using Context): Symbol

Attributes

Inherited from:
Capability
def assumedContainsOf(x: TypeRef)(using Context): SimpleIdentitySet[Capability]

Attributes

Inherited from:
Capability
protected def cached[C <: DerivedCapability](newRef: C): C

Attributes

Inherited from:
Capability
def captureSetOfInfo(using Context): CaptureSet

The capture set of the type underlying this reference

The capture set of the type underlying this reference

Attributes

Inherited from:
Capability
final def ccOwner(using Context): Symbol

Attributes

Inherited from:
Capability
final def classifier(using Context): Symbol

The classifier, either given in an explicit .only or assumed for a FreshCap. AnyRef for unclassified FreshCaps. Otherwise NoSymbol if no classifier is given.

The classifier, either given in an explicit .only or assumed for a FreshCap. AnyRef for unclassified FreshCaps. Otherwise NoSymbol if no classifier is given.

Attributes

Inherited from:
Capability
def computeHiddenSet(f: Refs => Refs)(using Context): Refs

Compute result based on hidden set of this capability. Restrictions and read-only status transfer from the capability to its hidden set.

Compute result based on hidden set of this capability. Restrictions and read-only status transfer from the capability to its hidden set.

Value parameters

f

a function that gets applied to all detected hidden sets

Attributes

Inherited from:
Capability
final def core: CoreCapability | RootCapability

The non-derived capability underlying this capability

The non-derived capability underlying this capability

Attributes

Inherited from:
Capability
final def coreType: CoreCapability | NoType.type

The type underlying this capability, NoType for root capabilities

The type underlying this capability, NoType for root capabilities

Attributes

Inherited from:
Capability
final def covers(y: Capability)(using Context): Boolean

x covers y if we should retain y when computing the overlap of two footprints which have x respectively y as elements. We assume that .rd have already been stripped on both sides. We have:

x covers y if we should retain y when computing the overlap of two footprints which have x respectively y as elements. We assume that .rd have already been stripped on both sides. We have:

x covers x x covers y ==> x covers y.f x covers y ==> x* covers y*, x? covers y? x covers y ==> covers y x covers y ==> x.only[C] covers y, x covers y.only[C]

TODO what other clauses from subsumes do we need to port here? The last clause is a conservative over-approximation: basically, we can't achieve separation by having different classifiers for now. It would be good to have a test that would expect such separation, then we can try to refine the clause to make the test pass.

Attributes

Inherited from:
Capability
final def coversFresh(y: Capability)(using Context): Boolean

x eq y or x is a fresh cap, y is a fresh cap with prefix p, and there is a prefix of p that contains x in its capture set.

x eq y or x is a fresh cap, y is a fresh cap with prefix p, and there is a prefix of p that contains x in its capture set.

Attributes

Inherited from:
Capability
def derivesFromCapTrait(cls: ClassSymbol)(using Context): Boolean

Tests whether the capability derives from capability class cls.

Tests whether the capability derives from capability class cls.

Attributes

Inherited from:
Capability
def derivesFromCapability(using Context): Boolean

Attributes

Inherited from:
Capability
def derivesFromShared(using Context): Boolean

Attributes

Inherited from:
Capability
def derivesFromStateful(using Context): Boolean

Attributes

Inherited from:
Capability
def derivesFromUnscoped(using Context): Boolean

Attributes

Inherited from:
Capability
def fallbackToText(printer: Printer): Text

A fallback text representation, if the pattern matching in Printers does not have a case for this showable element

A fallback text representation, if the pattern matching in Printers does not have a case for this showable element

Attributes

Inherited from:
Showable
def hiddenSet(using Context): Refs

The elements hidden by this capability, if this is a FreshCap or a derived version of one. Read-only status and restrictions are transferred from the capability to its hidden set.

The elements hidden by this capability, if this is a FreshCap or a derived version of one. Read-only status and restrictions are transferred from the capability to its hidden set.

Attributes

Inherited from:
Capability
def invalidateCaches(): Unit

Attributes

Inherited from:
Capability
final def isCapOrFresh(using Context): Boolean

Is this reference the generic root capability cap or a Fresh instance?

Is this reference the generic root capability cap or a Fresh instance?

Attributes

Inherited from:
Capability
final def isExclusive(required: Boolean = ...)(using Context): Boolean

An exclusive capability is a capability that derives indirectly from a maximal capability without going through a read-only capability or a capability classified as SharedCapability first.

An exclusive capability is a capability that derives indirectly from a maximal capability without going through a read-only capability or a capability classified as SharedCapability first.

Value parameters

required

if true, exclusivity can be obtained by setting the mutability status of some capture set variable from Ignored to Writer.

Attributes

Inherited from:
Capability
def isKnownClassifiedAs(cls: ClassSymbol)(using Context): Boolean

Attributes

Inherited from:
Capability
def isKnownEmpty(using Context): Boolean

Attributes

Inherited from:
Capability
final def isMaybe(using Context): Boolean

Is this a maybe reference of the form x??

Is this a maybe reference of the form x??

Attributes

Inherited from:
Capability
final def isParamPath(using Context): Boolean

Attributes

Inherited from:
Capability
final def isReach(using Context): Boolean

Is this a reach reference of the form x* or a readOnly or maybe variant of a reach reference?

Is this a reach reference of the form x* or a readOnly or maybe variant of a reach reference?

Attributes

Inherited from:
Capability
final def isReadOnly(using Context): Boolean

Is this a read-only reference of the form x.rd or x.rd? or a capture set variable with only read-ony references in its upper bound?

Is this a read-only reference of the form x.rd or x.rd? or a capture set variable with only read-ony references in its upper bound?

Attributes

Inherited from:
Capability
final def isTerminalCapability(using Context): Boolean

Is this reference a root capability or a derived version of one? These capabilities have themselves as their captureSetOfInfo.

Is this reference a root capability or a derived version of one? These capabilities have themselves as their captureSetOfInfo.

Attributes

Inherited from:
Capability
final def isTracked(using Context): Boolean

Is the reference tracked? This is true if it can be tracked and the capture set of the underlying type is not always empty.

Is the reference tracked? This is true if it can be tracked and the capture set of the underlying type is not always empty.

Attributes

Inherited from:
Capability
final def isWellformed(using Context): Boolean

Attributes

Inherited from:
Capability
final def levelOwner(using Context): Symbol

The symbol that represents the level closest-enclosing ccOwner. Symbols representing levels are

The symbol that represents the level closest-enclosing ccOwner. Symbols representing levels are

  • class symbols, but not inner (non-static) module classes
  • method symbols, but not accessors or constructors For Unscoped FreshCaps the level owner is the top-level class.

Attributes

Inherited from:
Capability
def maxSubsumes(y: Capability, canAddHidden: Boolean)(using ctx: Context)(using vs: VarState = ...): Boolean

This is a maximal capability that subsumes y in given context and VarState.

This is a maximal capability that subsumes y in given context and VarState.

Value parameters

canAddHidden

If true we allow maximal capabilities to subsume all other capabilities. We add those capabilities to the hidden set if this is a Fresh instance. If false we only accept y elements that are already in the hidden set of this Fresh instance. The idea is that in a VarState that accepts additions we first run maxSubsumes with canAddHidden = false so that new variables get added to the sets. If that fails, we run the test again with canAddHidden = true as a last effort before we fail a comparison.

Attributes

Inherited from:
Capability
def maybe: Maybe

Attributes

Inherited from:
Capability
final def maybeExclusive(using Context): Boolean

Similar to isExlusive, but also includes capabilties with capture set variables in their info whose status is still open.

Similar to isExlusive, but also includes capabilties with capture set variables in their info whose status is still open.

Attributes

Inherited from:
Capability
final def paramPathRoot(using Context): Type

Attributes

Inherited from:
Capability
final def pathOwner(using Context): Symbol

The logical owner of the root of this class:

The logical owner of the root of this class:

  • If this path starts with C.this, the class C.
  • If it starts with a reference r, r's owner.
  • If it starts with cap, the scala.caps package class.
  • If it starts with a fresh instance, its owner.
  • If it starts with a ParamRef or a ResultCap, NoSymbol.

Attributes

Inherited from:
Capability
final def pathRoot(using Context): Capability

The first element of this path type, skipping selections and qualifiers. Note that class parameter references are of the form this.C but their pathroot is still this.C, not this.

The first element of this path type, skipping selections and qualifiers. Note that class parameter references are of the form this.C but their pathroot is still this.C, not this.

Attributes

Inherited from:
Capability
def productElementNames: Iterator[String]

An iterator over the names of all the elements of this product.

An iterator over the names of all the elements of this product.

Attributes

Inherited from:
Product
def productIterator: Iterator[Any]

An iterator over all the elements of this product.

An iterator over all the elements of this product.

Attributes

Returns

in the default implementation, an Iterator[Any]

Inherited from:
Product
def reach: Reach | Restricted | ReadOnly | Maybe

Attributes

Inherited from:
Capability
def readOnly: ReadOnly | Maybe

Attributes

Inherited from:
Capability
def restrict(cls: ClassSymbol)(using Context): Restricted | ReadOnly | Maybe

Attributes

Inherited from:
Capability
def show(using Context): String

The string representation of this showable element.

The string representation of this showable element.

Attributes

Inherited from:
Showable
def showAsCapability(using Context): String

Attributes

Inherited from:
Capability
def showIndented(margin: Int)(using Context): String

The string representation with each line after the first one indented by the given given margin (in spaces).

The string representation with each line after the first one indented by the given given margin (in spaces).

Attributes

Inherited from:
Showable
def showSummary(depth: Int = ...)(using Context): String

The summarized string representation of this showable element. Recursion depth is limited to some smallish value. Default is Config.summarizeDepth.

The summarized string representation of this showable element. Recursion depth is limited to some smallish value. Default is Config.summarizeDepth.

Attributes

Inherited from:
Showable
def singletonCaptureSet(using Context): Const

The capture set consisting of exactly this reference

The capture set consisting of exactly this reference

Attributes

Inherited from:
Capability
final def stripMaybe(using Context): Capability

Attributes

Inherited from:
Capability
final def stripReach(using Context): Capability

Attributes

Inherited from:
Capability
final def stripReadOnly(using Context): Capability

Attributes

Inherited from:
Capability
final def stripRestricted(using Context): Capability

Attributes

Inherited from:
Capability
final def stripRestricted(cls: ClassSymbol)(using Context): Capability

Drop restrictions with clss cls or a superclass of cls

Drop restrictions with clss cls or a superclass of cls

Attributes

Inherited from:
Capability
final def subsumes(y: Capability)(using ctx: Context)(using vs: VarState = ...): Boolean

x subsumes x x =:= y ==> x subsumes y x subsumes y ==> x subsumes y.f x subsumes y ==> x* subsumes y, x subsumes y? x subsumes y ==> x* subsumes y*, x? subsumes y? x: x1.type /\ x1 subsumes y ==> x subsumes y X = CapSet^cx, exists rx in cx, rx subsumes y ==> X subsumes y Y = CapSet^cy, forall ry in cy, x subsumes ry ==> x subsumes Y X: CapSet^c1...CapSet^c2, (CapSet^c1) subsumes y ==> X subsumes y Y: CapSet^c1...CapSet^c2, x subsumes (CapSet^c2) ==> x subsumes Y Contains[X, y] ==> X subsumes y

x subsumes x x =:= y ==> x subsumes y x subsumes y ==> x subsumes y.f x subsumes y ==> x* subsumes y, x subsumes y? x subsumes y ==> x* subsumes y*, x? subsumes y? x: x1.type /\ x1 subsumes y ==> x subsumes y X = CapSet^cx, exists rx in cx, rx subsumes y ==> X subsumes y Y = CapSet^cy, forall ry in cy, x subsumes ry ==> x subsumes Y X: CapSet^c1...CapSet^c2, (CapSet^c1) subsumes y ==> X subsumes y Y: CapSet^c1...CapSet^c2, x subsumes (CapSet^c2) ==> x subsumes Y Contains[X, y] ==> X subsumes y

Attributes

Inherited from:
Capability
def toText(printer: Printer): Text

The text representation of this showable element. This normally dispatches to a pattern matching method in Printers.

The text representation of this showable element. This normally dispatches to a pattern matching method in Printers.

Attributes

Inherited from:
Capability
def toType(using Context): Type

The type representing this capability. Note this method does not distinguish different RootCapability instances, and should only be used for printing or phases not related to CC.

The type representing this capability. Note this method does not distinguish different RootCapability instances, and should only be used for printing or phases not related to CC.

Attributes

Inherited from:
Capability
def transClassifiers(using Context): Classifiers

The transitive classifiers of this capability.

The transitive classifiers of this capability.

Attributes

Inherited from:
Capability
def tryClassifyAs(cls: ClassSymbol)(using Context): Boolean

Attributes

Inherited from:
Capability
final def visibility(using Context): Symbol

Attributes

Inherited from:
Capability
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Copyright (c) 2002-2026, LAMP/EPFL
Copyright (c) 2002-2026, LAMP/EPFL