Signature

dotty.tools.dotc.core.Signature
See theSignature companion object
case class Signature(paramsSig: List[ParamSig], resSig: TypeName)

The signature of a denotation.

Same-named denotations with different signatures are considered to be overloads, see SingleDenotation#matches for more details.

A method signature (a value of type Signature, excluding NotAMethod and OverloadedSignature) is composed of a list of parameter signatures, plus a type signature for the final result type.

A parameter signature (a value of type ParamSig) is either an integer, representing the number of type parameters in a type parameter section, or the type signature of a term parameter.

A type signature is the fully qualified name of the type symbol of the type's erasure.

For instance a definition

def f[T, S](x: Int)(y: List[T]): S

would have signature

Signature(
  List(2, "scala.Int".toTypeName, "scala.collection.immutable.List".toTypeName),
  "java.lang.Object".toTypeName)

Note that paramsSig has one entry for a whole type parameter section but one entry for each term parameter (currently, methods in Dotty can only have one type parameter section but this encoding leaves the door open for supporting multiple sections).

The signatures of non-method types are always NotAMethod.

There are three kinds of "missing" parts of signatures:

  • tpnme.EMPTY Result type marker for NotAMethod and OverloadedSignature
  • tpnme.WILDCARD Arises from a Wildcard or error type
  • tpnme.Uninstantiated Arises from an uninstantiated type variable

Attributes

Companion:
object
Graph
Supertypes
trait Product
trait Equals
class Object
trait Matchable
class Any

Members list

Concise view

Value members

Concrete methods

def clashes(that: Signature)(using Context): Boolean

Does this signature potentially clash with that ?

Does this signature potentially clash with that ?

Attributes

final def consistentParams(that: Signature)(using Context): Boolean

Does this signature coincide with that signature on their parameter parts? This is the case if all parameter signatures are consistent, i.e. they are either equal or on of them is tpnme.Uninstantiated.

Does this signature coincide with that signature on their parameter parts? This is the case if all parameter signatures are consistent, i.e. they are either equal or on of them is tpnme.Uninstantiated.

Attributes

A signature is under-defined if its paramsSig part contains at least one tpnme.Uninstantiated. Under-defined signatures arise when taking a signature of a type that still contains uninstantiated type variables.

A signature is under-defined if its paramsSig part contains at least one tpnme.Uninstantiated. Under-defined signatures arise when taking a signature of a type that still contains uninstantiated type variables.

Attributes

final def matchDegree(that: Signature)(using Context): MatchDegree

The degree to which this signature matches that. If parameter signatures are consistent and result types names match (i.e. they are the same or one is a wildcard), the result is FullMatch. If only the parameter signatures are consistent, the result is either MethodNotAMethodMatch (if one side is a method signature and the other isn't), or ParamMatch. If the parameters are inconsistent, the result is always NoMatch.

The degree to which this signature matches that. If parameter signatures are consistent and result types names match (i.e. they are the same or one is a wildcard), the result is FullMatch. If only the parameter signatures are consistent, the result is either MethodNotAMethodMatch (if one side is a method signature and the other isn't), or ParamMatch. If the parameters are inconsistent, the result is always NoMatch.

Attributes

def prependTermParams(params: List[Type], sourceLanguage: SourceLanguage)(using Context): Signature

Construct a signature by prepending the signature names of the given params to the parameter part of this signature.

Construct a signature by prepending the signature names of the given params to the parameter part of this signature.

Like Signature#apply, the result is only cacheable if isUnderDefined == false.

Attributes

def prependTypeParams(typeParamSigsSectionLength: Int)(using Context): Signature

Construct a signature by prepending the length of a type parameter section to the parameter part of this signature.

Construct a signature by prepending the length of a type parameter section to the parameter part of this signature.

Like Signature#apply, the result is only cacheable if isUnderDefined == false.

Attributes

final def updateWith(that: Signature): Signature

that signature, but keeping all corresponding parts of this signature.

that signature, but keeping all corresponding parts of this signature.

Attributes

Inherited methods

Attributes

Inherited from:
Product

Attributes

Inherited from:
Product