abstract class MacroExpander extends AnyRef
Performs macro expansion:
Expandable trees
A term of one of the following shapes:
Ident(<term macro>) Select(<any qualifier>, <term macro>) TypeApply(<any of the above>, <targs>) Apply(...Apply(<any of the above>, <args1>)...<argsN>)
Macro expansion
First of all macroExpandXXX
:
1) If necessary desugars the expandee
to fit into the default expansion scheme
that is understood by macroExpandWithRuntime
/ macroExpandWithoutRuntime
Then macroExpandWithRuntime
:
2) Checks whether the expansion needs to be delayed
3) Loads macro implementation using macroMirror
4) Synthesizes invocation arguments for the macro implementation
5) Checks that the result is a tree or an expr bound to this universe
Finally macroExpandXXX
:
6) Validates the expansion against the white list of supported tree shapes
7) Typechecks the result as required by the circumstances of the macro application
If -Ymacro-debug-lite is enabled, you will get basic notifications about macro expansion along with macro expansions logged in the form that can be copy/pasted verbatim into REPL.
If -Ymacro-debug-verbose is enabled, you will get detailed log of how exactly this function performs class loading and method resolution in order to load the macro implementation. The log will also include other non-trivial steps of macro expansion.
- returns
the expansion result if the expansion has been successful, the fallback tree if the expansion has been unsuccessful, but there is a fallback, the expandee unchanged if the expansion has been delayed, the expandee fully expanded if the expansion has been delayed before and has been expanded now, the expandee with an error marker set if the expansion has been cancelled due malformed arguments or implementation the expandee with an error marker set if there has been an error
- Source
- Macros.scala
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- MacroExpander
- AnyRef
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- by any2stringadd
- by StringFormat
- by Ensuring
- by ArrowAssoc
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Instance Constructors
- new MacroExpander(typer: Analyzer.Typer, expandee: Global.Tree)
Abstract Value Members
- abstract def onFallback(expanded: Global.Tree): Global.Tree
- abstract def onSuccess(expanded: Global.Tree): Global.Tree
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 Analyzer.MacroExpander to any2stringadd[Analyzer.MacroExpander] performed by method any2stringadd in scala.Predef.
- Definition Classes
- any2stringadd
-
def
->[B](y: B): (Analyzer.MacroExpander, B)
- Implicit
- This member is added by an implicit conversion from Analyzer.MacroExpander to ArrowAssoc[Analyzer.MacroExpander] 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
- def apply(desugared: Global.Tree): Global.Tree
-
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: (Analyzer.MacroExpander) ⇒ Boolean, msg: ⇒ Any): Analyzer.MacroExpander
- Implicit
- This member is added by an implicit conversion from Analyzer.MacroExpander to Ensuring[Analyzer.MacroExpander] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
def
ensuring(cond: (Analyzer.MacroExpander) ⇒ Boolean): Analyzer.MacroExpander
- Implicit
- This member is added by an implicit conversion from Analyzer.MacroExpander to Ensuring[Analyzer.MacroExpander] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
def
ensuring(cond: Boolean, msg: ⇒ Any): Analyzer.MacroExpander
- Implicit
- This member is added by an implicit conversion from Analyzer.MacroExpander to Ensuring[Analyzer.MacroExpander] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
def
ensuring(cond: Boolean): Analyzer.MacroExpander
- Implicit
- This member is added by an implicit conversion from Analyzer.MacroExpander to Ensuring[Analyzer.MacroExpander] 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
expand(desugared: Global.Tree): Global.Tree
- Attributes
- protected
- val expandee: Global.Tree
-
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 Analyzer.MacroExpander to StringFormat[Analyzer.MacroExpander] 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
- def onDelayed(expanded: Global.Tree): Global.Tree
- def onFailure(expanded: Global.Tree): Global.Tree
- def onSkipped(expanded: Global.Tree): Global.Tree
- def onSuppressed(expandee: Global.Tree): Global.Tree
-
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
- val typer: Analyzer.Typer
-
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): (Analyzer.MacroExpander, B)
- Implicit
- This member is added by an implicit conversion from Analyzer.MacroExpander to ArrowAssoc[Analyzer.MacroExpander] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc
The Scala compiler API.
The following resources are useful for Scala plugin/compiler development: