trait Enclosures extends AnyRef
EXPERIMENTAL
A slice of the Scala macros context that exposes enclosing trees (method, class, compilation unit and currently compiled macro application), the enclosing position of the macro expansion, as well as macros and implicits that are currently in-flight.
Starting from Scala 2.11.0, the APIs to get the trees enclosing by the current macro application are deprecated,
and the reasons for that are two-fold. Firstly, we would like to move towards the philosophy of locally-expanded macros,
as it has proven to be important for understanding of code. Secondly, within the current architecture of scalac,
we are unable to have c.enclosingTree-style APIs working robustly. Required changes to the typechecker would greatly
exceed the effort that we would like to expend on this feature given the existence of more pressing concerns at the moment.
This is somewhat aligned with the overall evolution of macros during the 2.11 development cycle, where we played with
c.introduceTopLevel
and c.introduceMember
, but at the end of the day decided to reject them.
If you're relying on the now deprecated APIs, consider using the new c.internal.enclosingOwner method that can be used to obtain the names of enclosing definitions. Alternatively try reformulating your macros in terms of completely local expansion and/or joining a discussion of a somewhat related potential language feature at https://groups.google.com/forum/#!topic/scala-debate/f4CLmYShX6Q. We also welcome questions and suggestions on our mailing lists, where we would be happy to further discuss this matter.
- Self Type
- blackbox.Context
- Source
- Enclosures.scala
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Type Members
-
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.
Indicates than one of the enclosure methods failed to find a tree of required type among enclosing trees.
- Annotations
- @deprecated
- Deprecated
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
- See also
Abstract Value Members
-
abstract
def
enclosingMacros: List[blackbox.Context]
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
enclosingMacros
stack, and it will most likely contain at least one macro with a position-ful macro application. SeeenclosingPosition
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. -
abstract
def
enclosingPosition: blackbox.Context.Position
Tries to guess a position for the enclosing application.
Tries to guess a position for the enclosing application. But that is simple, right? Just dereference
pos
ofmacroApplication
? 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 theenclosingMacros
stack. -
abstract
def
macroApplication: blackbox.Context.Tree
The tree that undergoes macro expansion.
The tree that undergoes macro expansion. Can be useful to get an offset or a range position of the entire tree being processed.
-
abstract
def
enclosingClass: blackbox.Context.Tree
Tree that corresponds to the enclosing class, or EmptyTree if not applicable.
Tree that corresponds to the enclosing class, or EmptyTree if not applicable.
- Annotations
- @deprecated
- Deprecated
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
- See also
-
abstract
def
enclosingDef: Universe.DefDef
Tree that corresponds to the enclosing DefDef tree.
Tree that corresponds to the enclosing DefDef tree. Throws
EnclosureException
if there's no such enclosing tree.- Annotations
- @deprecated
- Deprecated
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
- See also
-
abstract
def
enclosingImpl: Universe.ImplDef
Tree that corresponds to the enclosing ImplDef tree (i.e.
Tree that corresponds to the enclosing ImplDef tree (i.e. either ClassDef or ModuleDef). Throws
EnclosureException
if there's no such enclosing tree.- Annotations
- @deprecated
- Deprecated
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
- See also
-
abstract
def
enclosingMethod: blackbox.Context.Tree
Tree that corresponds to the enclosing method, or EmptyTree if not applicable.
Tree that corresponds to the enclosing method, or EmptyTree if not applicable.
- Annotations
- @deprecated
- Deprecated
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
- See also
-
abstract
def
enclosingPackage: Universe.PackageDef
Tree that corresponds to the enclosing PackageDef tree.
Tree that corresponds to the enclosing PackageDef tree. Throws
EnclosureException
if there's no such enclosing tree.- Annotations
- @deprecated
- Deprecated
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
- See also
-
abstract
def
enclosingRun: blackbox.Context.Run
Compilation run that contains this macro application.
Compilation run that contains this macro application.
- Annotations
- @deprecated
- Deprecated
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
- See also
-
abstract
def
enclosingTemplate: Universe.Template
Tree that corresponds to the enclosing Template tree.
Tree that corresponds to the enclosing Template tree. Throws
EnclosureException
if there's no such enclosing tree.- Annotations
- @deprecated
- Deprecated
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
- See also
-
abstract
def
enclosingUnit: blackbox.Context.CompilationUnit
Compilation unit that contains this macro application.
Compilation unit that contains this macro application.
- Annotations
- @deprecated
- Deprecated
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
- See also
Concrete Value Members
-
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
-
final
def
##(): Int
Equivalent to
x.hashCode
except for boxed numeric types andnull
.Equivalent to
x.hashCode
except for boxed numeric types andnull
. 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. Fornull
returns a hashcode wherenull.hashCode
throws aNullPointerException
.- returns
a hash value consistent with ==
- Definition Classes
- AnyRef → Any
-
def
+(other: String): String
- Implicit
- This member is added by an implicit conversion from Enclosures to any2stringadd[Enclosures] performed by method any2stringadd in scala.Predef.
- Definition Classes
- any2stringadd
-
def
->[B](y: B): (Enclosures, B)
- Implicit
- This member is added by an implicit conversion from Enclosures to ArrowAssoc[Enclosures] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc
- Annotations
- @inline()
-
final
def
==(arg0: Any): Boolean
The expression
x == that
is equivalent toif (x eq null) that eq null else x.equals(that)
.The expression
x == that
is equivalent toif (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
-
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 aClassCastException
at runtime, while the expressionList(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 typeT0
.
-
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
-
def
ensuring(cond: (Enclosures) ⇒ Boolean, msg: ⇒ Any): Enclosures
- Implicit
- This member is added by an implicit conversion from Enclosures to Ensuring[Enclosures] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
def
ensuring(cond: (Enclosures) ⇒ Boolean): Enclosures
- Implicit
- This member is added by an implicit conversion from Enclosures to Ensuring[Enclosures] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
def
ensuring(cond: Boolean, msg: ⇒ Any): Enclosures
- Implicit
- This member is added by an implicit conversion from Enclosures to Ensuring[Enclosures] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
def
ensuring(cond: Boolean): Enclosures
- Implicit
- This member is added by an implicit conversion from Enclosures to Ensuring[Enclosures] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
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 ofAnyRef
, and has three additional properties:- It is consistent: for any non-null instances
x
andy
of typeAnyRef
, multiple invocations ofx.eq(y)
consistently returnstrue
or consistently returnsfalse
. - For any non-null instance
x
of typeAnyRef
,x.eq(null)
andnull.eq(x)
returnsfalse
. null.eq(null)
returnstrue
.
When overriding the
equals
orhashCode
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
- It is consistent: for any non-null instances
-
def
equals(arg0: Any): Boolean
The equality method for reference types.
-
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 betweenfinalize
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
-
def
formatted(fmtstr: String): String
- Implicit
- This member is added by an implicit conversion from Enclosures to StringFormat[Enclosures] performed by method StringFormat in scala.Predef.
- Definition Classes
- StringFormat
- Annotations
- @inline()
-
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
-
def
hashCode(): Int
The hashCode method for reference types.
-
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 returnfalse
, while the expressionList(1).isInstanceOf[List[String]]
will returntrue
. 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 typeT0
;false
otherwise.
- Definition Classes
- Any
-
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
-
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
-
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
-
final
def
synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
- AnyRef
-
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
-
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( ... )
-
def
→[B](y: B): (Enclosures, B)
- Implicit
- This member is added by an implicit conversion from Enclosures to ArrowAssoc[Enclosures] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc