t

scala.tools.nsc.typechecker

TypeDiagnostics

trait TypeDiagnostics extends AnyRef

An interface to enable higher configurability of diagnostic messages regarding type errors. This is barely a beginning as error messages are distributed far and wide across the codebase. The plan is to partition error messages into some broad groups and provide some mechanism for being more or less verbose on a selective basis. Possible groups include such examples as

arity errors kind errors variance errors ambiguity errors volatility/stability errors implementation restrictions

And more, and there is plenty of overlap, so it'll be a process.

Self Type
Analyzer with StdAttachments
Source
TypeDiagnostics.scala
Version

1.0

Linear Supertypes
AnyRef, Any
Known Subclasses
erasure, treeChecker, ScaladocAnalyzer, InteractiveAnalyzer, Erasure, Duplicator, SpecializationDuplicator, Analyzer, Duplicators, TreeCheckers
Type Hierarchy
Ordering
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  2. By Inheritance
Inherited
  1. TypeDiagnostics
  2. AnyRef
  3. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
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Visibility
  1. Public
  2. All

Type Members

  1. case class TypeDiag(tp: Global.Type, sym: Global.Symbol) extends Ordered[(TypeDiagnostics.this)#TypeDiag] with Product with Serializable
  2. trait TyperDiagnostics extends AnyRef

Value Members

  1. def abstractVarMessage(sym: Global.Symbol): String

    An explanatory note to be added to error messages when there's a problem with abstract var defs

  2. def alternatives(tree: Global.Tree): List[Global.Type]
  3. def alternativesString(tree: Global.Tree): String
  4. def decodeWithKind(name: Global.Name, owner: Global.Symbol): String
  5. def disambiguate(ss: List[String]): collection.immutable.List[String]
  6. final def exampleTuplePattern(names: List[Global.Name]): String

    [a, b, c] => "(a, b, c)" [a, B] => "(param1, param2)" [a, B, c] => "(param1, ..., param2)"

  7. def existentialContext(tp: Global.Type): String
  8. def explainAlias(tp: Global.Type): String
  9. def explainAnyVsAnyRef(found: Global.Type, req: Global.Type): String
  10. def explainVariance(found: Global.Type, req: Global.Type): String

    Look through the base types of the found type for any which might have been valid subtypes if given conformant type arguments.

    Look through the base types of the found type for any which might have been valid subtypes if given conformant type arguments. Examine those for situations where the type error would have been eliminated if the variance were different. In such cases, append an additional explanatory message.

    TODO: handle type aliases better.

  11. def finalOwners(tpe: Global.Type): Boolean
  12. def foundReqMsg(found: Global.Type, req: Global.Type): String
  13. def linePrecedes(t1: Global.Tree, t2: Global.Tree): Boolean
  14. def posPrecedes(p1: Global.Position, p2: Global.Position): Boolean

    Does the positioned line assigned to t1 precede that of t2?

  15. final def recursivelyFinal(tpe: Global.Type): Boolean
    Annotations
    @tailrec()
  16. def restrictionError(pos: Global.Position, unit: Global.CompilationUnit, msg: String): Unit
  17. def restrictionWarning(pos: Global.Position, unit: Global.CompilationUnit, msg: String): Unit

    For errors which are artifacts of the implementation: such messages indicate that the restriction may be lifted in the future.

  18. def setAddendum(pos: Global.Position, msg: () ⇒ String): Unit
  19. def treeSymTypeMsg(tree: Global.Tree): String
  20. def typePatternAdvice(sym: Global.Symbol, ptSym: Global.Symbol): String
  21. def typingInPattern[T](body: ⇒ T): T

    Devising new ways of communicating error info out of desperation to work on error messages.

    Devising new ways of communicating error info out of desperation to work on error messages. This is used by typedPattern to wrap its business so we can generate a sensible error message when things go south.

  22. def underlyingSymbol(member: Global.Symbol): Global.Symbol

    The symbol which the given accessor represents (possibly in part).

    The symbol which the given accessor represents (possibly in part). This is used for error messages, where we want to speak in terms of the actual declaration or definition, not in terms of the generated setters and getters.

    TODO: is it wise to create new symbols simply to generate error message? is this safe in interactive/resident mode?

  23. def withAddendum(pos: Global.Position): (String) ⇒ String
  24. def withDisambiguation[T](locals: List[Global.Symbol], types: Global.Type*)(op: ⇒ T): T

    Given any number of types, alters the name information in the symbols until they can be distinguished from one another: then executes the given code.

    Given any number of types, alters the name information in the symbols until they can be distinguished from one another: then executes the given code. The names are restored and the result is returned.