scala.tools.nsc.transform.patmat.ScalacPatternExpanders

# ScalacPatternExpander

#### trait ScalacPatternExpander extends PatternExpander[Global.Tree, Global.Type]

Source
  ScalacPatternExpanders.scala

Linear Supertypes
PatternExpander[Global.Tree, Global.Type], AnyRef, Any
Known Subclasses
alignPatterns
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Inherited

1. ScalacPatternExpander
2. PatternExpander
3. AnyRef
4. Any

Implicitly

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

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1. Public
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### Type Members

1. #### final case class Aligned(patterns: Patterns, extractor: Extractor) extends Product with Serializable

   If elementArity is...

   If elementArity is... 0: A perfect match between extractor and the fixed patterns. If there is a star pattern it will match any sequence. > 0: There are more patterns than products. There will have to be a sequence which can populate at least <elementArity> patterns. < 0: There are more products than patterns: compile time error.

   Definition Classes
     PatternExpander

2. #### final case class Extractor(whole: Type, fixed: List[Type], repeated: Repeated) extends Product with Serializable

   An 'extractor' can be a case class or an unapply or unapplySeq method.

   An 'extractor' can be a case class or an unapply or unapplySeq method. Decoding what it is that they extract takes place before we arrive here, so that this class can concentrate only on the relationship between patterns and types.

   In a case class, the class is the unextracted type and the fixed and repeated types are derived from its constructor parameters.

   In an unapply, this is reversed: the parameter to the unapply is the unextracted type, and the other types are derived based on the return type of the unapply method.

   In other words, this case class and unapply are encoded the same:

   case class Foo(x: Int, y: Int, zs: Char*) def unapplySeq(x: Foo): Option[(Int, Int, Seq[Char])]

   Both are Extractor(Foo, Int :: Int :: Nil, Repeated(Seq[Char], Char, Char*))

   whole

     The type in its unextracted form

   fixed

     The non-sequence types which are extracted

   repeated

     The sequence type which is extracted

   Definition Classes
     PatternExpander

3. #### final case class Patterns(fixed: List[Pattern], star: Pattern) extends Product with Serializable

   Definition Classes
     PatternExpander

4. #### sealed case class Repeated(sequenceType: Type, elementType: Type, repeatedType: Type) extends Product with Serializable

   It's not optimal that we're carrying both sequence and repeated type here, but the implementation requires more unraveling before it can be avoided.

   It's not optimal that we're carrying both sequence and repeated type here, but the implementation requires more unraveling before it can be avoided.

   sequenceType is Seq[T], elementType is T, repeatedType is T*.

   Definition Classes
     PatternExpander

5. #### final case class TypedPat(pat: Pattern, tpe: Type) extends Product with Serializable

   Definition Classes
     PatternExpander

### 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 ScalacPatternExpander to any2stringadd[ScalacPatternExpander] performed by method any2stringadd in scala.Predef.
   Definition Classes
     any2stringadd

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

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

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

   Definition Classes
     AnyRef → Any

6. #### def NoPattern: Global.EmptyTree.type

   You'll note we're not inside the cake.

   You'll note we're not inside the cake. "Pattern" and "Type" are arbitrary types here, and NoPattern and NoType arbitrary values.

   Definition Classes
     ScalacPatternExpander → PatternExpander

7. #### object NoRepeated extends Repeated

   Definition Classes
     PatternExpander

8. #### def NoType: Global.NoType.type

   Definition Classes
     ScalacPatternExpander → PatternExpander

9. #### def applyMethodTypes(method: Global.Type): Extractor

   In this case we are basing the pattern expansion on a case class constructor.

   In this case we are basing the pattern expansion on a case class constructor. The argument is the MethodType carried by the primary constructor.

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

    Definition Classes
      Any

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

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

12. #### def elementTypeOf(tpe: Global.Type): Global.Type

13. #### def ensuring(cond: (ScalacPatternExpander) ⇒ Boolean, msg: ⇒ Any): ScalacPatternExpander

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

14. #### def ensuring(cond: (ScalacPatternExpander) ⇒ Boolean): ScalacPatternExpander

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

15. #### def ensuring(cond: Boolean, msg: ⇒ Any): ScalacPatternExpander

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

16. #### def ensuring(cond: Boolean): ScalacPatternExpander

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

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

    Definition Classes
      AnyRef

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

    Definition Classes
      AnyRef → Any

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

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

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

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

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

    Definition Classes
      AnyRef → Any

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

    Definition Classes
      AnyRef → Any

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

    Definition Classes
      Any

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

    Definition Classes
      AnyRef

25. #### def newExtractor(whole: Global.Type, fixed: List[Global.Type], repeated: Repeated): Extractor

26. #### def newPatterns(patterns: List[Global.Tree]): Patterns

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

    Definition Classes
      AnyRef

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

    Definition Classes
      AnyRef

29. #### def repeatedFromSeq(seqType: Global.Type): Repeated

30. #### def repeatedFromVarargs(repeated: Global.Type): Repeated

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

    Definition Classes
      AnyRef

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

    Definition Classes
      AnyRef → Any

33. #### def unapplyMethodTypes(method: Global.Type, isSeq: Boolean): Extractor

    In this case, expansion is based on an unapply or unapplySeq method.

    In this case, expansion is based on an unapply or unapplySeq method. Unfortunately the MethodType does not carry the information of whether it was unapplySeq, so we have to funnel that information in separately.

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

    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

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

    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

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

    Definition Classes
      AnyRef
    Annotations
      @throws( ... )

37. #### def →[B](y: B): (ScalacPatternExpander, B)

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

### Inherited from PatternExpander[Global.Tree, Global.Type]

### Inherited from AnyRef

### Inherited from Any

### Inherited by implicit conversion any2stringadd from ScalacPatternExpander to any2stringadd[ScalacPatternExpander]

### Inherited by implicit conversion StringFormat from ScalacPatternExpander to StringFormat[ScalacPatternExpander]

### Inherited by implicit conversion Ensuring from ScalacPatternExpander to Ensuring[ScalacPatternExpander]

### Inherited by implicit conversion ArrowAssoc from ScalacPatternExpander to ArrowAssoc[ScalacPatternExpander]

### Ungrouped