Trait

scala.reflect.macros

Typers

Related Doc: package macros

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trait Typers extends AnyRef

EXPERIMENTAL

A slice of the Scala macros context that partially exposes the type checker to macro writers.

Self Type
blackbox.Context
Source
Typers.scala
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Type Members

  1. type TypecheckException = macros.TypecheckException

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    See also

    scala.reflect.macros.TypecheckException

  2. abstract type TypecheckMode

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    Represents mode of operations of the typechecker underlying c.typecheck calls.

    Represents mode of operations of the typechecker underlying c.typecheck calls. Is necessary since the shape of the typechecked tree alone is not enough to guess how it should be typechecked. Can be EXPRmode (typecheck as a term), TYPEmode (typecheck as a type) or PATTERNmode (typecheck as a pattern).

Abstract Value Members

  1. abstract val PATTERNmode: blackbox.Context.TypecheckMode

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    Indicates that an argument to c.typecheck should be typechecked as a pattern.

  2. abstract val TERMmode: blackbox.Context.TypecheckMode

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    Indicates that an argument to c.typecheck should be typechecked as a term.

    Indicates that an argument to c.typecheck should be typechecked as a term. This is the default typechecking mode in Scala 2.11 and the only one supported in Scala 2.10.

  3. abstract val TYPEmode: blackbox.Context.TypecheckMode

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    Indicates that an argument to c.typecheck should be typechecked as a type.

  4. abstract def inferImplicitValue(pt: blackbox.Context.Type, silent: Boolean = true, withMacrosDisabled: Boolean = false, pos: blackbox.Context.Position = enclosingPosition): blackbox.Context.Tree

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    Infers an implicit value of the expected type pt in the macro callsite context.

    Infers an implicit value of the expected type pt in the macro callsite context. Optional pos parameter provides a position that will be associated with the implicit search.

    If silent is false, TypecheckException will be thrown in case of an inference error. If silent is true, the typecheck is silent and will return EmptyTree if an error occurs. Such errors don't vanish and can be inspected by turning on -Xlog-implicits. Unlike in typecheck, silent is true by default.

    Exceptions thrown
  5. abstract def inferImplicitView(tree: blackbox.Context.Tree, from: blackbox.Context.Type, to: blackbox.Context.Type, silent: Boolean = true, withMacrosDisabled: Boolean = false, pos: blackbox.Context.Position = enclosingPosition): blackbox.Context.Tree

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    Infers an implicit view from the provided tree tree of the type from to the type to in the macro callsite context.

    Infers an implicit view from the provided tree tree of the type from to the type to in the macro callsite context. Optional pos parameter provides a position that will be associated with the implicit search.

    If silent is false, TypecheckException will be thrown in case of an inference error. If silent is true, the typecheck is silent and will return EmptyTree if an error occurs. Such errors don't vanish and can be inspected by turning on -Xlog-implicits. Unlike in typecheck, silent is true by default.

    Exceptions thrown
  6. abstract def openMacros: List[blackbox.Context]

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    Contexts that represent macros in-flight, including the current one.

    Contexts that represent macros in-flight, including the current one. Very much like a stack trace, but for macros only. Can be useful for interoperating with other macros and for imposing compiler-friendly limits on macro expansion.

    Is also priceless for emitting sane error messages for macros that are called by other macros on synthetic (i.e. position-less) trees. In that dire case navigate the openMacros stack, and it will most likely contain at least one macro with a position-ful macro application. See enclosingPosition for a default implementation of this logic.

    Unlike enclosingMacros, this is a def, which means that it gets recalculated on every invocation, so it might change depending on what is going on during macro expansion.

  7. abstract def typecheck(tree: blackbox.Context.Tree, mode: blackbox.Context.TypecheckMode = TERMmode, pt: blackbox.Context.Type = universe.WildcardType, silent: Boolean = false, withImplicitViewsDisabled: Boolean = false, withMacrosDisabled: Boolean = false): blackbox.Context.Tree

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    Typechecks the provided tree against the expected type pt in the macro callsite context under typechecking mode specified in mode with EXPRmode being default.

    Typechecks the provided tree against the expected type pt in the macro callsite context under typechecking mode specified in mode with EXPRmode being default. This populates symbols and types of the tree and possibly transforms it to reflect certain desugarings.

    If silent is false, TypecheckException will be thrown in case of a typecheck error. If silent is true, the typecheck is silent and will return EmptyTree if an error occurs. Such errors don't vanish and can be inspected by turning on -Ymacro-debug-verbose. Unlike in inferImplicitValue and inferImplicitView, silent is false by default.

    Typechecking can be steered with the following optional parameters: withImplicitViewsDisabled recursively prohibits implicit views (though, implicit vals will still be looked up and filled in), default value is false withMacrosDisabled recursively prohibits macro expansions and macro-based implicits, default value is false

    Exceptions thrown
  8. abstract def untypecheck(tree: blackbox.Context.Tree): blackbox.Context.Tree

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    In the current implementation of Scala's reflection API, untyped trees (also known as parser trees or unattributed trees) are observationally different from typed trees (also known as typer trees, typechecked trees or attributed trees),

    In the current implementation of Scala's reflection API, untyped trees (also known as parser trees or unattributed trees) are observationally different from typed trees (also known as typer trees, typechecked trees or attributed trees),

    Usually, if some compiler API takes a tree, then both untyped and typed trees will do. However in some cases, only untyped or only typed trees are appropriate. For example, eval only accepts untyped trees and one can only splice typed trees inside typed trees. Therefore in the current reflection API, there is a need in functions that go back and forth between untyped and typed trees. For this we have typecheck and untypecheck.

    Note that untypecheck is currently afflicted by https://issues.scala-lang.org/browse/SI-5464, which makes it sometimes corrupt trees so that they don't make sense anymore. Unfortunately, there's no workaround for that. We plan to fix this issue soon, but for now please keep it in mind.

    See also

    http://stackoverflow.com/questions/20936509/scala-macros-what-is-the-difference-between-typed-aka-typechecked-an-untyped

  9. abstract def resetLocalAttrs(tree: blackbox.Context.Tree): blackbox.Context.Tree

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    Recursively resets locally defined symbols and types in a given tree.

    Recursively resets locally defined symbols and types in a given tree. WARNING: Don't use this API, go for untypecheck instead.

    Annotations
    @deprecated
    Deprecated

    (Since version 2.11.0) Use c.untypecheck instead

Concrete Value Members

  1. final def !=(arg0: Any): Boolean

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    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

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    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

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    Implicit information
    This member is added by an implicit conversion from Typers to any2stringadd[Typers] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ->[B](y: B): (Typers, B)

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    Implicit information
    This member is added by an implicit conversion from Typers to ArrowAssoc[Typers] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()
  5. final def ==(arg0: Any): Boolean

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    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. val TypecheckException: macros.TypecheckException.type

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    See also

    scala.reflect.macros.TypecheckException

  7. final def asInstanceOf[T0]: T0

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    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

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    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: (Typers) ⇒ Boolean, msg: ⇒ Any): Typers

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    Implicit information
    This member is added by an implicit conversion from Typers to Ensuring[Typers] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  10. def ensuring(cond: (Typers) ⇒ Boolean): Typers

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    Implicit information
    This member is added by an implicit conversion from Typers to Ensuring[Typers] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  11. def ensuring(cond: Boolean, msg: ⇒ Any): Typers

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    Implicit information
    This member is added by an implicit conversion from Typers to Ensuring[Typers] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  12. def ensuring(cond: Boolean): Typers

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    Implicit information
    This member is added by an implicit conversion from Typers to Ensuring[Typers] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  13. final def eq(arg0: AnyRef): Boolean

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    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

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    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

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    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

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    Implicit information
    This member is added by an implicit conversion from Typers to StringFormat[Typers] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @inline()
  17. final def getClass(): Class[_]

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    A representation that corresponds to the dynamic class of the receiver object.

    A representation that corresponds to the dynamic class of the receiver object.

    The nature of the representation is platform dependent.

    returns

    a representation that corresponds to the dynamic class of the receiver object.

    Definition Classes
    AnyRef → Any
    Note

    not specified by SLS as a member of AnyRef

  18. def hashCode(): Int

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    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

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    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

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    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

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    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

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    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

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    Definition Classes
    AnyRef
  24. def toString(): String

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    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

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

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    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  27. final def wait(arg0: Long): Unit

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    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  28. def [B](y: B): (Typers, B)

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    Implicit information
    This member is added by an implicit conversion from Typers to ArrowAssoc[Typers] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc

Deprecated Value Members

  1. def typeCheck(tree: blackbox.Context.Tree, pt: blackbox.Context.Type = universe.WildcardType, silent: Boolean = false, withImplicitViewsDisabled: Boolean = false, withMacrosDisabled: Boolean = false): blackbox.Context.Tree

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    Annotations
    @deprecated
    Deprecated

    (Since version 2.11.0) Use c.typecheck instead

    See also

    Typers.typecheck