W3cubDocs

/Scala 2.12 Reflection

Trait scala.reflect.macros.blackbox.Context

trait Context extends Aliases with Enclosures with Names with Reifiers with FrontEnds with Infrastructure with Typers with Parsers with Evals with ExprUtils with Internals

EXPERIMENTAL

The blackbox 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 blackbox.Context, then this macro def becomes a blackbox macro, which means that its expansion will be upcast to its return type, enforcing faithfulness of that macro to its type signature. Whitebox macros, i.e. the ones defined with whitebox.Context, aren't bound by this restriction, which enables a number of important use cases, but they are also going to enjoy less support than blackbox macros, so choose wisely. See the Macros Guide for more information.

Source
Context.scala
See also

scala.reflect.macros.whitebox.Context

Linear Supertypes
Known Subclasses

Type Members

trait ContextInternalApi extends MacroInternalApi

Definition Classes
Internals
See also

scala.reflect.api.Internals

type Expr[+T] = Universe.Expr[T]

Expr wraps an abstract syntax tree and tags it with its type.

Definition Classes
Aliases

type Modifiers = Universe.Modifiers

The type of tree modifiers.

Definition Classes
Aliases

type Name = Universe.Name

The abstract type of names.

Definition Classes
Aliases

type Position = Universe.Position

Defines a universe-specific notion of positions.

Definition Classes
Aliases

abstract type PrefixType

The type of the prefix tree from which the macro is selected. See the documentation entry for prefix for an example.

type Scope = Universe.Scope

The base type of all scopes.

Definition Classes
Aliases

type Symbol = Universe.Symbol

The type of symbols representing declarations.

Definition Classes
Aliases

type TermName = Universe.TermName

The abstract type of names representing terms.

Definition Classes
Aliases

type Tree = Universe.Tree

The type of Scala abstract syntax trees.

Definition Classes
Aliases

type Type = Universe.Type

The type of Scala types, and also Scala type signatures. (No difference is internally made between the two).

Definition Classes
Aliases

type TypeName = Universe.TypeName

The abstract type of names representing types.

Definition Classes
Aliases

type TypeTag[T] = Universe.TypeTag[T]

The type of type tags.

Definition Classes
Aliases

type TypecheckException = macros.TypecheckException

Definition Classes
Typers
See also

scala.reflect.macros.TypecheckException

abstract type TypecheckMode

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 TERMmode (typecheck as a term), TYPEmode (typecheck as a type) or PATTERNmode (typecheck as a pattern).

Definition Classes
Typers

type WeakTypeTag[T] = Universe.WeakTypeTag[T]

The type of weak type tags.

Definition Classes
Aliases

case class EnclosureException(expected: Class[_], enclosingTrees: List[blackbox.Context.Tree]) extends Exception with Product with Serializable

Indicates than one of the enclosure methods failed to find a tree of required type among enclosing trees.

Definition Classes
Enclosures
Annotations
@deprecated
Deprecated

(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

See also

scala.reflect.macros.Enclosures

type CompilationUnit = Universe.CompilationUnit

The type of compilation units.

Definition Classes
Aliases
Annotations
@deprecated
Deprecated

(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

See also

scala.reflect.macros.Enclosures

type Run = Universe.Run

The type of compilation runs.

Definition Classes
Aliases
Annotations
@deprecated
Deprecated

(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

See also

scala.reflect.macros.Enclosures

Abstract Value Members

abstract def Expr[T](tree: Tree)(implicit arg0: WeakTypeTag[T]): Expr[T]

A shorthand to create an expr.

Unlike the conventional expr factory, which requires a scala.reflect.api.TreeCreator, this one accepts a regular tree, but the resulting exprs are unable of being migrated to other universes/mirrors (the functionality normally not needed for macros, since there is only one compile-time universe and only one compile-time mirror).

Definition Classes
Aliases

abstract val PATTERNmode: TypecheckMode

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

Definition Classes
Typers

abstract val TERMmode: TypecheckMode

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.

Definition Classes
Typers

abstract val TYPEmode: TypecheckMode

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

Definition Classes
Typers

abstract def TypeTag[T](tpe: Type): TypeTag[T]

A shorthand to create a type tag.

Unlike the conventional type tag factory, which requires a scala.reflect.api.TypeCreator, this one accepts a regular type, but the resulting type tags are unable of being migrated to other universes/mirrors (the functionality normally not needed for macros, since there is only one compile-time universe and only one compile-time mirror).

Definition Classes
Aliases

abstract def WeakTypeTag[T](tpe: Type): WeakTypeTag[T]

A shorthand to create a weak type tag.

Unlike the conventional type tag factory, which requires a scala.reflect.api.TypeCreator, this one accepts a regular type, but the resulting type tags are unable of being migrated to other universes/mirrors (the functionality normally not needed for macros, since there is only one compile-time universe and only one compile-time mirror).

Definition Classes
Aliases

abstract def abort(pos: Position, msg: String): Nothing

Abruptly terminates current macro expansion leaving a note about what happened. Use enclosingPosition if you're in doubt what position to pass to pos.

Definition Classes
FrontEnds

abstract def classPath: List[URL]

Exposes current classpath.

Definition Classes
Infrastructure

abstract def compilerSettings: List[String]

Exposes current compiler settings as a list of options. Use scalac -help, scalac -X and scalac -Y to learn about currently supported options.

Definition Classes
Infrastructure

abstract def echo(pos: Position, msg: String): Unit

For sending a message which should not be labelled as a warning/error, but also shouldn't require -verbose to be visible. Use enclosingPosition if you're in doubt what position to pass to pos.

Definition Classes
FrontEnds

abstract def enclosingMacros: List[Context]

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 enclosingMacros 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 openMacros, this is a val, which means that it gets initialized when the context is created and always stays the same regardless of whatever happens during macro expansion.

Definition Classes
Enclosures

abstract def enclosingPosition: Position

Tries to guess a position for the enclosing application. But that is simple, right? Just dereference pos of macroApplication? Not really. If we're in a synthetic macro expansion (no positions), we must do our best to infer the position of something that triggered this expansion. Surprisingly, quite often we can do this by navigation the enclosingMacros stack.

Definition Classes
Enclosures

abstract def error(pos: Position, msg: String): Unit

Emits a compilation error. Use enclosingPosition if you're in doubt what position to pass to pos.

Definition Classes
FrontEnds

abstract def eval[T](expr: Expr[T]): T

Takes a typed wrapper for a tree of type T and evaluates it to a value of type T.

Can be used to perform compile-time computations on macro arguments to the extent permitted by the shape of the arguments.

Known issues: because of https://github.com/scala/bug/issues/5748 trees being evaluated first need to undergo untypecheck. Resetting symbols and types mutates the tree in place, therefore the conventional approach is to duplicate the tree first.

scala> def impl(c: Context)(x: c.Expr[String]) = {
     | val x1 = c.Expr[String](c.untypecheck(x.tree.duplicate))
     | println(s"compile-time value is: ${c.eval(x1)}")
     | x
     | }
impl: (c: Context)(x: c.Expr[String])c.Expr[String]

scala> def test(x: String) = macro impl
test: (x: String)String

scala> test("x")
compile-time value is: x
res0: String = x

scala> test("x" + "y")
compile-time value is: xy
res1: String = xy

scala> val x = "x"
x: String = x

scala> test(x + "y")
compile-time value is: xy
res2: String = xy

scala> { val x = "x"; test(x + "y") }
error: exception during macro expansion:
scala.tools.reflect.ToolBoxError: reflective compilation failed

Note that in the last case evaluation has failed, because the argument of a macro refers to a runtime value x, which is unknown at compile time.

Definition Classes
Evals

abstract def freshName[NameType <: Name](name: NameType): NameType

Creates a more or less unique name having a given name as a prefix and having the same flavor (term name or type name) as the given name. Consult scala.reflect.macros.Names for more information on uniqueness of such names.

Definition Classes
Names

abstract def freshName(name: String): String

Creates a string that represents a more or less unique name having a given prefix. Consult scala.reflect.macros.Names for more information on uniqueness of such names.

Definition Classes
Names

abstract def freshName(): String

Creates a string that represents a more or less unique name. Consult scala.reflect.macros.Names for more information on uniqueness of such names.

Definition Classes
Names

abstract def hasErrors: Boolean

Does the compilation session have any errors?

Definition Classes
FrontEnds

abstract def hasWarnings: Boolean

Does the compilation session have any warnings?

Definition Classes
FrontEnds

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

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.

Definition Classes
Typers
Exceptions thrown

abstract def inferImplicitView(tree: Tree, from: Type, to: Type, silent: Boolean = true, withMacrosDisabled: Boolean = false, pos: Position = enclosingPosition): Tree

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.

Definition Classes
Typers
Exceptions thrown

abstract def info(pos: Position, msg: String, force: Boolean): Unit

Emits an informational message, suppressed unless -verbose or force=true. Use enclosingPosition if you're in doubt what position to pass to pos.

Definition Classes
FrontEnds

abstract val internal: ContextInternalApi

Definition Classes
Internals
See also

scala.reflect.api.Internals

abstract def macroApplication: Tree

The tree that undergoes macro expansion. Can be useful to get an offset or a range position of the entire tree being processed.

Definition Classes
Enclosures

abstract val mirror: Universe.Mirror

abstract def openMacros: List[Context]

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.

Definition Classes
Typers

abstract def parse(code: String): Tree

Parses a string with a Scala expression into an abstract syntax tree. Only works for expressions, i.e. parsing a package declaration will fail.

Definition Classes
Parsers
Exceptions thrown

abstract val prefix: Expr[PrefixType]

The prefix tree from which the macro is selected.

For example, for a macro filter defined as an instance method on a collection Coll, prefix represents an equivalent of this for normal instance methods:

scala> class Coll[T] {
     | def filter(p: T => Boolean): Coll[T] = macro M.filter[T]
     | }; object M {
     | def filter[T](c: Context { type PrefixType = Coll[T] })
     |              (p: c.Expr[T => Boolean]): c.Expr[Coll[T]] =
     |   {
     |     println(c.prefix.tree)
     |     c.prefix
     |   }
     | }
defined class Coll
defined module Macros

scala> new Coll[Int]().filter(_ % 2 == 0)
new Coll[Int]()
res0: Coll[Int] = ...

scala> val x = new Coll[String]()
x: Coll[String] = ...

scala> x.filter(_ != "")
$line11.$read.$iw.$iw.$iw.$iw.$iw.$iw.$iw.$iw.$iw.$iw.$iw.$iw.x
res1 @ 35563b4b: x.type = ...

Note how the value of prefix changes depending on the qualifier of the macro call (i.e. the expression that is at the left-hand side of the dot).

Another noteworthy thing about the snippet above is the Context { type PrefixType = Coll[T] } type that is used to stress that the macro implementation works with prefixes of type Coll[T].

abstract def reifyEnclosingRuntimeClass: Tree

Given a type, generate a tree that when compiled and executed produces the runtime class of the enclosing class or module. Returns EmptyTree if there does not exist an enclosing class or module.

Definition Classes
Reifiers

abstract def reifyRuntimeClass(tpe: Type, concrete: Boolean = true): Tree

Given a type, generate a tree that when compiled and executed produces the runtime class of the original type. If concrete is true, then this function will bail on types, who refer to abstract types (like ClassTag does).

Definition Classes
Reifiers

abstract def reifyTree(universe: Tree, mirror: Tree, tree: Tree): Tree

Given a tree, generate a tree that when compiled and executed produces the original tree. For more information and examples see the documentation for Universe.reify.

The produced tree will be bound to the specified universe and mirror. Possible values for universe include universe.internal.gen.mkRuntimeUniverseRef. Possible values for mirror include EmptyTree (in that case the reifier will automatically pick an appropriate mirror).

This function is deeply connected to Universe.reify, a macro that reifies arbitrary expressions into runtime trees. They do very similar things (Universe.reify calls Context.reifyTree to implement itself), but they operate on different metalevels (see below).

Let's study the differences between Context.reifyTree and Universe.reify on an example of using them inside a fooMacro macro:

* Since reify itself is a macro, it will be executed when fooMacro is being compiled (metalevel -1) and will produce a tree that when evaluated during macro expansion of fooMacro (metalevel 0) will recreate the input tree.

This provides a facility analogous to quasi-quoting. Writing "reify{ expr }" will generate an AST that represents expr. Afterwards this AST (or its parts) can be used to construct the return value of fooMacro.

* reifyTree is evaluated during macro expansion (metalevel 0) and will produce a tree that when evaluated during the runtime of the program (metalevel 1) will recreate the input tree.

This provides a way to retain certain trees from macro expansion time to be inspected later, in the runtime. For example, DSL authors may find it useful to capture DSL snippets into ASTs that are then processed at runtime in a domain-specific way.

Also note the difference between universes of the runtime trees produced by two reifies:

* The result of compiling and running the result of reify will be bound to the Universe that called reify. This is possible because it's a macro, so it can generate whatever code it wishes.

* The result of compiling and running the result of reifyTree will be the prefix that needs to be passed explicitly. This happens because the Universe of the evaluated result is from a different metalevel than the Context the called reify.

Typical usage of this function is to retain some of the trees received/created by a macro into the form that can be inspected (via pattern matching) or compiled/run (by a reflective ToolBox) during the runtime.

Definition Classes
Reifiers

abstract def reifyType(universe: Tree, mirror: Tree, tpe: Type, concrete: Boolean = false): Tree

Given a type, generate a tree that when compiled and executed produces the original type. The produced tree will be bound to the specified universe and mirror. For more information and examples see the documentation for Context.reifyTree and Universe.reify.

Definition Classes
Reifiers

abstract def settings: List[String]

Exposes macro-specific settings as a list of strings. These settings are passed to the compiler via the "-Xmacro-settings:setting1,setting2...,settingN" command-line option.

Definition Classes
Infrastructure

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

Typechecks the provided tree against the expected type pt in the macro callsite context under typechecking mode specified in mode with TERMmode 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

Definition Classes
Typers
Exceptions thrown

abstract val universe: Universe

abstract def unreifyTree(tree: Tree): Tree

Undoes reification of a tree.

This reversion doesn't simply restore the original tree (that would lose the context of reification), but does something more involved that conforms to the following laws:

1) unreifyTree(reifyTree(tree)) != tree // unreified tree is tree + saved context // in current implementation, the result of unreify is opaque // i.e. there's no possibility to inspect underlying tree/context

2) reifyTree(unreifyTree(reifyTree(tree))) == reifyTree(tree) // the result of reifying a tree in its original context equals to // the result of reifying a tree along with its saved context

3) compileAndEval(unreifyTree(reifyTree(tree))) ~ compileAndEval(tree) // at runtime original and unreified trees are behaviorally equivalent

Definition Classes
Reifiers

abstract def untypecheck(tree: Tree): Tree

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://github.com/scala/bug/issues/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.

Definition Classes
Typers
See also

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

abstract def warning(pos: Position, msg: String): Unit

Emits a warning. Use enclosingPosition if you're in doubt what position to pass to pos.

Definition Classes
FrontEnds

abstract def enclosingClass: Tree

Tree that corresponds to the enclosing class, or EmptyTree if not applicable.

Definition Classes
Enclosures
Annotations
@deprecated
Deprecated

(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

See also

scala.reflect.macros.Enclosures

abstract def enclosingDef: Universe.DefDef

Tree that corresponds to the enclosing DefDef tree. Throws EnclosureException if there's no such enclosing tree.

Definition Classes
Enclosures
Annotations
@deprecated
Deprecated

(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

See also

scala.reflect.macros.Enclosures

abstract def enclosingImpl: Universe.ImplDef

Tree that corresponds to the enclosing ImplDef tree (i.e. either ClassDef or ModuleDef). Throws EnclosureException if there's no such enclosing tree.

Definition Classes
Enclosures
Annotations
@deprecated
Deprecated

(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

See also

scala.reflect.macros.Enclosures

abstract def enclosingMethod: Tree

Tree that corresponds to the enclosing method, or EmptyTree if not applicable.

Definition Classes
Enclosures
Annotations
@deprecated
Deprecated

(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

See also

scala.reflect.macros.Enclosures

abstract def enclosingPackage: Universe.PackageDef

Tree that corresponds to the enclosing PackageDef tree. Throws EnclosureException if there's no such enclosing tree.

Definition Classes
Enclosures
Annotations
@deprecated
Deprecated

(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

See also

scala.reflect.macros.Enclosures

abstract def enclosingRun: Run

Compilation run that contains this macro application.

Definition Classes
Enclosures
Annotations
@deprecated
Deprecated

(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

See also

scala.reflect.macros.Enclosures

abstract def enclosingTemplate: Universe.Template

Tree that corresponds to the enclosing Template tree. Throws EnclosureException if there's no such enclosing tree.

Definition Classes
Enclosures
Annotations
@deprecated
Deprecated

(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

See also

scala.reflect.macros.Enclosures

abstract def enclosingUnit: CompilationUnit

Compilation unit that contains this macro application.

Definition Classes
Enclosures
Annotations
@deprecated
Deprecated

(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information

See also

scala.reflect.macros.Enclosures

abstract def fresh[NameType <: Name](name: NameType): NameType

Creates a more or less unique name having a given name as a prefix and having the same flavor (term name or type name) as the given name. Consult scala.reflect.macros.Names for more information on uniqueness of such names.

Definition Classes
Names
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use freshName instead

abstract def fresh(name: String): String

Creates a string that represents a more or less unique name having a given prefix. Consult scala.reflect.macros.Names for more information on uniqueness of such names.

Definition Classes
Names
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use freshName instead

abstract def fresh(): String

Creates a string that represents a more or less unique name. Consult scala.reflect.macros.Names for more information on uniqueness of such names.

Definition Classes
Names
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use freshName instead

abstract def literal(x: Char): Expr[Char]

Shorthand for Literal(Constant(x: Char)) in the underlying universe.

Definition Classes
ExprUtils
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use quasiquotes instead

abstract def literal(x: String): Expr[String]

Shorthand for Literal(Constant(x: String)) in the underlying universe.

Definition Classes
ExprUtils
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use quasiquotes instead

abstract def literal(x: Double): Expr[Double]

Shorthand for Literal(Constant(x: Double)) in the underlying universe.

Definition Classes
ExprUtils
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use quasiquotes instead

abstract def literal(x: Float): Expr[Float]

Shorthand for Literal(Constant(x: Float)) in the underlying universe.

Definition Classes
ExprUtils
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use quasiquotes instead

abstract def literal(x: Long): Expr[Long]

Shorthand for Literal(Constant(x: Long)) in the underlying universe.

Definition Classes
ExprUtils
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use quasiquotes instead

abstract def literal(x: Int): Expr[Int]

Shorthand for Literal(Constant(x: Int)) in the underlying universe.

Definition Classes
ExprUtils
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use quasiquotes instead

abstract def literal(x: Short): Expr[Short]

Shorthand for Literal(Constant(x: Short)) in the underlying universe.

Definition Classes
ExprUtils
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use quasiquotes instead

abstract def literal(x: Byte): Expr[Byte]

Shorthand for Literal(Constant(x: Byte)) in the underlying universe.

Definition Classes
ExprUtils
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use quasiquotes instead

abstract def literal(x: Boolean): Expr[Boolean]

Shorthand for Literal(Constant(x: Boolean)) in the underlying universe.

Definition Classes
ExprUtils
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use quasiquotes instead

abstract def literalFalse: Expr[Boolean]

Shorthand for Literal(Constant(false)) in the underlying universe.

Definition Classes
ExprUtils
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use quasiquotes instead

abstract def literalNull: Expr[Null]

Shorthand for Literal(Constant(null)) in the underlying universe.

Definition Classes
ExprUtils
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use quasiquotes instead

abstract def literalTrue: Expr[Boolean]

Shorthand for Literal(Constant(true)) in the underlying universe.

Definition Classes
ExprUtils
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use quasiquotes instead

abstract def literalUnit: Expr[Unit]

Shorthand for Literal(Constant(())) in the underlying universe.

Definition Classes
ExprUtils
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use quasiquotes instead

abstract def resetLocalAttrs(tree: Tree): Tree

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

Definition Classes
Typers
Annotations
@deprecated
Deprecated

(Since version 2.11.0) use c.untypecheck instead

Concrete Value Members

final def !=(arg0: Any): Boolean

Definition Classes
AnyRef → Any

final def ##(): Int

Definition Classes
AnyRef → Any

def +(other: String): String

Implicit
This member is added by an implicit conversion from Context to any2stringadd[Context] performed by method any2stringadd in scala.Predef.
Definition Classes
any2stringadd

def ->[B](y: B): (Context, B)

Implicit
This member is added by an implicit conversion from Context to ArrowAssoc[Context] performed by method ArrowAssoc in scala.Predef.
Definition Classes
ArrowAssoc
Annotations
@inline()

final def ==(arg0: Any): Boolean

Definition Classes
AnyRef → Any

val Expr: Universe.Expr.type

Constructor/Extractor for Expr.

Definition Classes
Aliases

val TypeTag: Universe.TypeTag.type

Constructor/Extractor for TypeTag.

Definition Classes
Aliases

val TypecheckException: macros.TypecheckException.type

Definition Classes
Typers
See also

scala.reflect.macros.TypecheckException

val WeakTypeTag: Universe.WeakTypeTag.type

Constructor/Extractor for WeakTypeTag.

Definition Classes
Aliases

final def asInstanceOf[T0]: T0

Definition Classes
Any

def clone(): AnyRef

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

def ensuring(cond: (Context) ⇒ Boolean, msg: ⇒ Any): Context

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

def ensuring(cond: (Context) ⇒ Boolean): Context

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

def ensuring(cond: Boolean, msg: ⇒ Any): Context

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

def ensuring(cond: Boolean): Context

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

final def eq(arg0: AnyRef): Boolean

Definition Classes
AnyRef

def equals(arg0: Any): Boolean

Definition Classes
AnyRef → Any

def finalize(): Unit

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

def formatted(fmtstr: String): String

Implicit
This member is added by an implicit conversion from Context to StringFormat[Context] performed by method StringFormat in scala.Predef.
Definition Classes
StringFormat
Annotations
@inline()

final def getClass(): Class[_]

Definition Classes
AnyRef → Any
Annotations
@native()

def hashCode(): Int

Definition Classes
AnyRef → Any
Annotations
@native()

final def isInstanceOf[T0]: Boolean

Definition Classes
Any

final def ne(arg0: AnyRef): Boolean

Definition Classes
AnyRef

final def notify(): Unit

Definition Classes
AnyRef
Annotations
@native()

final def notifyAll(): Unit

Definition Classes
AnyRef
Annotations
@native()

def symbolOf[T](implicit arg0: WeakTypeTag[T]): Universe.TypeSymbol

Type symbol of x as derived from a type tag.

Definition Classes
Aliases

final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
AnyRef

def toString(): String

Definition Classes
AnyRef → Any

def typeOf[T](implicit ttag: TypeTag[T]): Type

Shortcut for implicitly[TypeTag[T]].tpe

Definition Classes
Aliases

def typeTag[T](implicit ttag: TypeTag[T]): TypeTag[T]

Shortcut for implicitly[TypeTag[T]]

Definition Classes
Aliases

final def wait(): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )

final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )

final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
@throws( ... ) @native()

def weakTypeOf[T](implicit attag: WeakTypeTag[T]): Type

Shortcut for implicitly[WeakTypeTag[T]].tpe

Definition Classes
Aliases

def weakTypeTag[T](implicit attag: WeakTypeTag[T]): WeakTypeTag[T]

Shortcut for implicitly[WeakTypeTag[T]]

Definition Classes
Aliases

def [B](y: B): (Context, B)

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

© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.12.9/scala-reflect/scala/reflect/macros/blackbox/Context.html