Packages

  • package root

    The Scala compiler and reflection APIs.

    The Scala compiler and reflection APIs.

    Definition Classes
    root
  • package scala
    Definition Classes
    root
  • package tools
    Definition Classes
    scala
  • package nsc
    Definition Classes
    tools
  • package typechecker
    Definition Classes
    nsc
  • trait Contexts extends AnyRef

    Definition Classes
    typechecker
    Version

    1.0

  • class Context extends AnyRef

    A motley collection of the state and loosely associated behaviour of the type checker.

    A motley collection of the state and loosely associated behaviour of the type checker. Each Typer has an associated context, and as it descends into the tree new (Typer, Context) pairs are spawned.

    Meet the crew; first the state:

    • A tree, symbol, and scope representing the focus of the typechecker
    • An enclosing context, outer.
    • The current compilation unit.
    • A variety of bits that track the current error reporting policy (more on this later); whether or not implicits/macros are enabled, whether we are in a self or super call or in a constructor suffix. These are represented as bits in the mask contextMode.
    • Some odds and ends: undetermined type parameters of the current line of type inference; contextual augmentation for error messages, tracking of the nesting depth.

    And behaviour:

    • The central point for issuing errors and warnings from the typechecker, with a means to buffer these for use in 'silent' type checking, when some recovery might be possible.
    • Context is something of a Zipper for the tree were are typechecking: it enclosingContextChain is the path back to the root. This is exactly what we need to resolve names (lookupSymbol) and to collect in-scope implicit definitions (implicitss) Supporting these are imports, which represents all Import trees in in the enclosing context chain.
    • In a similar vein, we can assess accessibility (isAccessible.)

    More on error buffering: When are type errors recoverable? In quite a few places, it turns out. Some examples: trying to type an application with/without the expected type, or with/without implicit views enabled. This is usually mediated by Typer.silent, Inferencer#tryTwice.

    Initially, starting from the typer phase, the contexts either buffer or report errors; afterwards errors are thrown. This is configured in rootContext. Additionally, more fine grained control is needed based on the kind of error; ambiguity errors are often suppressed during exploratory typing, such as determining whether a == b in an argument position is an assignment or a named argument, when Inferencer#isApplicableSafe type checks applications with and without an expected type, or when Typer#tryTypedApply tries to fit arguments to a function type with/without implicit views.

    When the error policies entail error/warning buffering, the mutable ReportBuffer records everything that is issued. It is important to note, that child Contexts created with make "inherit" the very same ReportBuffer instance, whereas children spawned through makeSilent receive a separate, fresh buffer.

    Definition Classes
    Contexts
  • TryTwice

abstract class TryTwice extends AnyRef

Try inference twice: once without views and once with views, unless views are already disabled.

Source
Contexts.scala
Linear Supertypes
AnyRef, Any
Ordering
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  2. By Inheritance
Inherited
  1. TryTwice
  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

Instance Constructors

  1. new TryTwice()

Abstract Value Members

  1. abstract def tryOnce(isLastTry: Boolean): Unit

Concrete Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. def +(other: String): String
    Implicit
    This member is added by an implicit conversion from TryTwice to any2stringadd[TryTwice] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ->[B](y: B): (TryTwice, B)
    Implicit
    This member is added by an implicit conversion from TryTwice to ArrowAssoc[TryTwice] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()
  5. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  6. final def apply(): Unit
  7. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  8. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  9. def ensuring(cond: (TryTwice) ⇒ Boolean, msg: ⇒ Any): TryTwice
    Implicit
    This member is added by an implicit conversion from TryTwice to Ensuring[TryTwice] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  10. def ensuring(cond: (TryTwice) ⇒ Boolean): TryTwice
    Implicit
    This member is added by an implicit conversion from TryTwice to Ensuring[TryTwice] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  11. def ensuring(cond: Boolean, msg: ⇒ Any): TryTwice
    Implicit
    This member is added by an implicit conversion from TryTwice to Ensuring[TryTwice] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  12. def ensuring(cond: Boolean): TryTwice
    Implicit
    This member is added by an implicit conversion from TryTwice to Ensuring[TryTwice] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  13. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  14. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  15. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  16. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  17. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  18. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  19. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  20. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  21. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  22. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  23. def toString(): String
    Definition Classes
    AnyRef → Any
  24. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  25. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  26. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  27. def [B](y: B): (TryTwice, B)
    Implicit
    This member is added by an implicit conversion from TryTwice to ArrowAssoc[TryTwice] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc

Deprecated Value Members

  1. def formatted(fmtstr: String): String
    Implicit
    This member is added by an implicit conversion from TryTwice to StringFormat[TryTwice] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @deprecated @inline()
    Deprecated

    (Since version 2.12.16) Use formatString.format(value) instead of value.formatted(formatString), or use the f"" string interpolator. In Java 15 and later, formatted resolves to the new method in String which has reversed parameters.

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd from TryTwice to any2stringadd[TryTwice]

Inherited by implicit conversion StringFormat from TryTwice to StringFormat[TryTwice]

Inherited by implicit conversion Ensuring from TryTwice to Ensuring[TryTwice]

Inherited by implicit conversion ArrowAssoc from TryTwice to ArrowAssoc[TryTwice]

Ungrouped