scala.tools.nsc.typechecker.Macros

# MacroExpander

#### 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

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AnyRef, Any
Known Subclasses
DefMacroExpander
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Inherited

1. MacroExpander
2. AnyRef
3. Any

Implicitly

1. by any2stringadd
2. by StringFormat
3. by Ensuring
4. by ArrowAssoc

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### Instance Constructors

1. #### new MacroExpander(typer: Analyzer.Typer, expandee: Global.Tree)

### Abstract Value Members

1. #### abstract def onFallback(expanded: Global.Tree): Global.Tree

2. #### abstract def onSuccess(expanded: Global.Tree): Global.Tree

### Concrete Value Members

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

   Definition Classes
     AnyRef → Any

2. #### final def ##(): Int

   Definition Classes
     AnyRef → Any

3. #### def +(other: String): String

   Implicit information
     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

4. #### def ->[B](y: B): (Analyzer.MacroExpander, B)

   Implicit information
     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()

5. #### final def ==(arg0: Any): Boolean

   Definition Classes
     AnyRef → Any

6. #### def apply(desugared: Global.Tree): Global.Tree

7. #### final def asInstanceOf[T0]: T0

   Definition Classes
     Any

8. #### def clone(): AnyRef

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

9. #### def ensuring(cond: (Analyzer.MacroExpander) ⇒ Boolean, msg: ⇒ Any): Analyzer.MacroExpander

   Implicit information
     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

10. #### def ensuring(cond: (Analyzer.MacroExpander) ⇒ Boolean): Analyzer.MacroExpander

    Implicit information
      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

11. #### def ensuring(cond: Boolean, msg: ⇒ Any): Analyzer.MacroExpander

    Implicit information
      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

12. #### def ensuring(cond: Boolean): Analyzer.MacroExpander

    Implicit information
      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

13. #### final def eq(arg0: AnyRef): Boolean

    Definition Classes
      AnyRef

14. #### def equals(arg0: Any): Boolean

    Definition Classes
      AnyRef → Any

15. #### def expand(desugared: Global.Tree): Global.Tree

    Attributes
      protected

16. #### val expandee: Global.Tree

17. #### def finalize(): Unit

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

18. #### def formatted(fmtstr: String): String

    Implicit information
      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()

19. #### final def getClass(): Class[_]

    Definition Classes
      AnyRef → Any

20. #### def hashCode(): Int

    Definition Classes
      AnyRef → Any

21. #### final def isInstanceOf[T0]: Boolean

    Definition Classes
      Any

22. #### final def ne(arg0: AnyRef): Boolean

    Definition Classes
      AnyRef

23. #### final def notify(): Unit

    Definition Classes
      AnyRef

24. #### final def notifyAll(): Unit

    Definition Classes
      AnyRef

25. #### def onDelayed(expanded: Global.Tree): Global.Tree

26. #### def onFailure(expanded: Global.Tree): Global.Tree

27. #### def onSkipped(expanded: Global.Tree): Global.Tree

28. #### def onSuppressed(expandee: Global.Tree): Global.Tree

29. #### final def synchronized[T0](arg0: ⇒ T0): T0

    Definition Classes
      AnyRef

30. #### def toString(): String

    Definition Classes
      AnyRef → Any

31. #### val typer: Analyzer.Typer

32. #### final def wait(): Unit

    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

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

    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

34. #### final def wait(arg0: Long): Unit

    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

35. #### def →[B](y: B): (Analyzer.MacroExpander, B)

    Implicit information
      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

### Inherited from AnyRef

### Inherited from Any

### Inherited by implicit conversion any2stringadd from Analyzer.MacroExpander to any2stringadd[Analyzer.MacroExpander]

### Inherited by implicit conversion StringFormat from Analyzer.MacroExpander to StringFormat[Analyzer.MacroExpander]

### Inherited by implicit conversion Ensuring from Analyzer.MacroExpander to Ensuring[Analyzer.MacroExpander]

### Inherited by implicit conversion ArrowAssoc from Analyzer.MacroExpander to ArrowAssoc[Analyzer.MacroExpander]

### Ungrouped