Packages

  • package root

    The Scala compiler API.

    The Scala compiler API.

    The following resources are useful for Scala plugin/compiler development:

    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
Type Hierarchy
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

    Test two objects for inequality.

    Test two objects for inequality.

    returns

    true if !(this == that), false otherwise.

    Definition Classes
    AnyRef → Any
  2. final def ##(): Int

    Equivalent to x.hashCode except for boxed numeric types and null.

    Equivalent to x.hashCode except for boxed numeric types and null. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For null returns a hashcode where null.hashCode throws a NullPointerException.

    returns

    a hash value consistent with ==

    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

    The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).

    The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    Definition Classes
    AnyRef → Any
  6. final def apply(): Unit
  7. final def asInstanceOf[T0]: T0

    Cast the receiver object to be of type T0.

    Cast the receiver object to be of type T0.

    Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expression List(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.

    returns

    the receiver object.

    Definition Classes
    Any
    Exceptions thrown

    ClassCastException if the receiver object is not an instance of the erasure of type T0.

  8. def clone(): AnyRef

    Create a copy of the receiver object.

    Create a copy of the receiver object.

    The default implementation of the clone method is platform dependent.

    returns

    a copy of the receiver object.

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
    Note

    not specified by SLS as a member of AnyRef

  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

    Tests whether the argument (that) is a reference to the receiver object (this).

    Tests whether the argument (that) is a reference to the receiver object (this).

    The eq method implements an equivalence relation on non-null instances of AnyRef, and has three additional properties:

    • It is consistent: for any non-null instances x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false.
    • For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false.
    • null.eq(null) returns true.

    When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).

    returns

    true if the argument is a reference to the receiver object; false otherwise.

    Definition Classes
    AnyRef
  14. def equals(arg0: Any): Boolean

    The equality method for reference types.

    The equality method for reference types. Default implementation delegates to eq.

    See also equals in scala.Any.

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    Definition Classes
    AnyRef → Any
  15. def finalize(): Unit

    Called by the garbage collector on the receiver object when there are no more references to the object.

    Called by the garbage collector on the receiver object when there are no more references to the object.

    The details of when and if the finalize method is invoked, as well as the interaction between finalize and non-local returns and exceptions, are all platform dependent.

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
    Note

    not specified by SLS as a member of AnyRef

  16. 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
    @inline()
  17. final def getClass(): Class[_]

    Returns the runtime class representation of the object.

    Returns the runtime class representation of the object.

    returns

    a class object corresponding to the runtime type of the receiver.

    Definition Classes
    AnyRef → Any
  18. def hashCode(): Int

    The hashCode method for reference types.

    The hashCode method for reference types. See hashCode in scala.Any.

    returns

    the hash code value for this object.

    Definition Classes
    AnyRef → Any
  19. final def isInstanceOf[T0]: Boolean

    Test whether the dynamic type of the receiver object is T0.

    Test whether the dynamic type of the receiver object is T0.

    Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression 1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will return true. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.

    returns

    true if the receiver object is an instance of erasure of type T0; false otherwise.

    Definition Classes
    Any
  20. final def ne(arg0: AnyRef): Boolean

    Equivalent to !(this eq that).

    Equivalent to !(this eq that).

    returns

    true if the argument is not a reference to the receiver object; false otherwise.

    Definition Classes
    AnyRef
  21. final def notify(): Unit

    Wakes up a single thread that is waiting on the receiver object's monitor.

    Wakes up a single thread that is waiting on the receiver object's monitor.

    Definition Classes
    AnyRef
    Note

    not specified by SLS as a member of AnyRef

  22. final def notifyAll(): Unit

    Wakes up all threads that are waiting on the receiver object's monitor.

    Wakes up all threads that are waiting on the receiver object's monitor.

    Definition Classes
    AnyRef
    Note

    not specified by SLS as a member of AnyRef

  23. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  24. def toString(): String

    Creates a String representation of this object.

    Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.

    returns

    a String representation of the object.

    Definition Classes
    AnyRef → Any
  25. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  26. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  27. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  28. 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

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