Scala Compiler2.12.2 < Back
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# Packages

-  package root

  The Scala compiler and reflection APIs.

  The Scala compiler and reflection APIs.

  Definition Classes
    root
-  package scala
  Definition Classes
    root
-  package tools
  Definition Classes
    scala
-  package nsc
  Definition Classes
    tools
-  package transform
  Definition Classes
    nsc
-  package patmat
  Definition Classes
    transform
-  trait ScalacPatternExpanders extends AnyRef

  This is scalac-specific logic layered on top of the scalac-agnostic "matching products to patterns" logic defined in PatternExpander.

  This is scalac-specific logic layered on top of the scalac-agnostic "matching products to patterns" logic defined in PatternExpander.

  Definition Classes
    patmat
- AlignedOps
- ScalacPatternExpander
- alignPatterns

t

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
Type Hierarchy
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2. By Inheritance

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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Visibility

1. Public
2. All

### 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, typeOfSinglePattern: Type) 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.  object NoRepeated extends Repeated
   Definition Classes
     PatternExpander
2.  final def !=(arg0: Any): Boolean
   Definition Classes
     AnyRef → Any
3.  final def ##(): Int
   Definition Classes
     AnyRef → Any
4.  def +(other: String): String
   Implicit
     This member is added by an implicit conversion from ScalacPatternExpander to any2stringadd[ScalacPatternExpander] performed by method any2stringadd in scala.Predef.
   Definition Classes
     any2stringadd
5.  def ->[B](y: B): (ScalacPatternExpander, B)
   Implicit
     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()
6.  final def ==(arg0: Any): Boolean
   Definition Classes
     AnyRef → Any
7.  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
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
      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
      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
      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
      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
      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 newExtractor(whole: Global.Type, fixed: List[Global.Type], repeated: Repeated, typeOfSinglePattern: Global.Type): Extractor
27.  def newPatterns(patterns: List[Global.Tree]): Patterns
28.  final def notify(): Unit
    Definition Classes
      AnyRef
29.  final def notifyAll(): Unit
    Definition Classes
      AnyRef
30.  def repeatedFromSeq(seqType: Global.Type): Repeated
31.  def repeatedFromVarargs(repeated: Global.Type): Repeated
32.  final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
      AnyRef
33.  def toString(): String
    Definition Classes
      AnyRef → Any
34.  def unapplyMethodTypes(context: (analyzer)#Context, whole: Global.Type, result: 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.

35.  final def wait(): Unit
    Definition Classes
      AnyRef
    Annotations
      @throws( ... )
36.  final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
      AnyRef
    Annotations
      @throws( ... )
37.  final def wait(arg0: Long): Unit
    Definition Classes
      AnyRef
    Annotations
      @throws( ... )
38.  def →[B](y: B): (ScalacPatternExpander, B)
    Implicit
      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