Packages

  • package root
    Definition Classes
    root
  • package scala
    Definition Classes
    root
  • package reflect
    Definition Classes
    scala
  • package macros

    EXPERIMENTAL

    EXPERIMENTAL

    The base package for Scala macros.

    Macros are functions that are called by the compiler during compilation. Within these functions the programmer has access to compiler APIs. For example, it is possible to generate, analyze and typecheck code.

    See the Macros Guide on how to get started with Scala macros.

    Definition Classes
    reflect
  • package whitebox
    Definition Classes
    macros
  • trait Context extends blackbox.Context

    EXPERIMENTAL

    EXPERIMENTAL

    The whitebox Scala macros context.

    See the overview page for a description of how macros work. This documentation entry provides information on the API available to macro writers.

    A macro context wraps a compiler universe exposed in universe and having type scala.reflect.macros.Universe. This type is a refinement over the generic reflection API provided in scala.reflect.api.Universe. The extended Universe provides mutability for reflection artifacts (e.g. macros can change types of compiler trees, add annotation to symbols representing definitions, etc) and exposes some internal compiler functionality such as Symbol.deSkolemize or Tree.attachments.

    Another fundamental part of a macro context is macroApplication, which provides access to the tree undergoing macro expansion. Parts of this tree can be found in arguments of the corresponding macro implementations and in prefix, but macroApplication gives the full picture.

    Other than that, macro contexts provide facilities for typechecking, exploring the compiler's symbol table and enclosing trees and compilation units, evaluating trees, logging warnings/errors and much more. Refer to the documentation of top-level traits in this package to learn the details.

    If a macro def refers to a macro impl that uses whitebox.Context, then this macro def becomes a whitebox macro, gaining the ability to refine the type of its expansion beyond its official return type, which enables a number of important use cases. Blackbox macros, i.e. the ones defined with blackbox.Context, can't do that, so they are less powerful. However blackbox macros are also going to enjoy better support than whitebox macros, so choose wisely. See the Macros Guide for more information.

    Definition Classes
    whitebox
    See also

    scala.reflect.macros.blackbox.Context

  • ContextInternalApi
  • EnclosureException
  • ImplicitCandidate
  • PrefixType
  • TypecheckMode

case class ImplicitCandidate(pre: Context.Type, sym: Context.Symbol, pt: Context.Type, tree: Context.Tree) extends Product with Serializable

Information about one of the currently considered implicit candidates. Candidates are used in plural form, because implicit parameters may themselves have implicit parameters, hence implicit searches can recursively trigger other implicit searches.

pre and sym provide information about the candidate itself. pt and tree store the parameters of the implicit search the candidate is participating in.

Source
Context.scala
Linear Supertypes
java.io.Serializable, Product, Equals, AnyRef, Any
Type Hierarchy
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. ImplicitCandidate
  2. Serializable
  3. Product
  4. Equals
  5. AnyRef
  6. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. Protected

Instance Constructors

  1. new ImplicitCandidate(pre: Context.Type, sym: Context.Symbol, pt: Context.Type, tree: Context.Tree)

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 ImplicitCandidate toany2stringadd[ImplicitCandidate] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ->[B](y: B): (ImplicitCandidate, B)
    Implicit
    This member is added by an implicit conversion from ImplicitCandidate toArrowAssoc[ImplicitCandidate] 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 asInstanceOf[T0]: T0
    Definition Classes
    Any
  7. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.CloneNotSupportedException]) @native()
  8. def ensuring(cond: (ImplicitCandidate) => Boolean, msg: => Any): ImplicitCandidate
    Implicit
    This member is added by an implicit conversion from ImplicitCandidate toEnsuring[ImplicitCandidate] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  9. def ensuring(cond: (ImplicitCandidate) => Boolean): ImplicitCandidate
    Implicit
    This member is added by an implicit conversion from ImplicitCandidate toEnsuring[ImplicitCandidate] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  10. def ensuring(cond: Boolean, msg: => Any): ImplicitCandidate
    Implicit
    This member is added by an implicit conversion from ImplicitCandidate toEnsuring[ImplicitCandidate] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  11. def ensuring(cond: Boolean): ImplicitCandidate
    Implicit
    This member is added by an implicit conversion from ImplicitCandidate toEnsuring[ImplicitCandidate] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  12. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  13. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.Throwable])
  14. def formatted(fmtstr: String): String
    Implicit
    This member is added by an implicit conversion from ImplicitCandidate toStringFormat[ImplicitCandidate] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @inline()
  15. final def getClass(): Class[_ <: AnyRef]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  16. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  17. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  18. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  19. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  20. val pre: Context.Type
  21. def productElementNames: Iterator[String]
    Definition Classes
    Product
  22. val pt: Context.Type
  23. val sym: Context.Symbol
  24. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  25. val tree: Context.Tree
  26. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  27. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  28. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException]) @native()

Deprecated Value Members

  1. def →[B](y: B): (ImplicitCandidate, B)
    Implicit
    This member is added by an implicit conversion from ImplicitCandidate toArrowAssoc[ImplicitCandidate] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @deprecated
    Deprecated

    (Since version 2.13.0) Use -> instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.

Inherited from java.io.Serializable

Inherited from Product

Inherited from Equals

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd fromImplicitCandidate to any2stringadd[ImplicitCandidate]

Inherited by implicit conversion StringFormat fromImplicitCandidate to StringFormat[ImplicitCandidate]

Inherited by implicit conversion Ensuring fromImplicitCandidate to Ensuring[ImplicitCandidate]

Inherited by implicit conversion ArrowAssoc fromImplicitCandidate to ArrowAssoc[ImplicitCandidate]

Ungrouped