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.
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
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.
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.
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 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.
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.
Tree that corresponds to the enclosing class, or EmptyTree if not applicable.
Tree that corresponds to the enclosing class, or EmptyTree if not applicable.
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
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.
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
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.
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
Tree that corresponds to the enclosing method, or EmptyTree if not applicable.
Tree that corresponds to the enclosing method, or EmptyTree if not applicable.
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
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.
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
Compilation run that contains this macro application.
Compilation run that contains this macro application.
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
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.
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
Compilation unit that contains this macro application.
Compilation unit that contains this macro application.
(Since version 2.11.0) c.enclosingTree-style APIs are now deprecated; consult the scaladoc for more information
Test two objects for inequality.
Test two objects for inequality.
true if !(this == that), false otherwise.
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.
a hash value consistent with ==
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).
true if the receiver object is equivalent to the argument; false otherwise.
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.
the receiver object.
ClassCastException if the receiver object is not an instance of the erasure of type T0.
Create a copy of the receiver object.
Create a copy of the receiver object.
The default implementation of the clone method is platform dependent.
a copy of the receiver object.
not specified by SLS as a member of AnyRef
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:
x and y of type AnyRef, multiple invocations of
x.eq(y) consistently returns true or consistently returns false.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).
true if the argument is a reference to the receiver object; false otherwise.
The equality method for reference types.
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.
not specified by SLS as a member of AnyRef
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.
a representation that corresponds to the dynamic class of the receiver object.
not specified by SLS as a member of AnyRef
The hashCode method for reference types.
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.
true if the receiver object is an instance of erasure of type T0; false otherwise.
Equivalent to !(this eq that).
Equivalent to !(this eq that).
true if the argument is not a reference to the receiver object; false otherwise.
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.
not specified by SLS as a member of AnyRef
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.
not specified by SLS as a member of AnyRef
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.
a String representation of the object.
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.introduceTopLevelandc.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.