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 PatternExpansion extends AnyRef

    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.

    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.

    An extractor returns: F1, F2, ..., Fi, opt[Seq[E] or E*] A case matches: P1, P2, ..., Pj, opt[Seq[E]] Put together: P1/F1, P2/F2, ... Pi/Fi, Pi+1/E, Pi+2/E, ... Pj/E, opt[Seq[E]]

    Here Pm/Fi is the last pattern to match the fixed arity section.

    productArity: the value of i, i.e. the number of non-sequence types in the extractor nonStarArity: the value of j, i.e. the number of non-star patterns in the case definition elementArity: j - i, i.e. the number of non-star patterns which must match sequence elements starArity: 1 or 0 based on whether there is a star (sequence-absorbing) pattern totalArity: nonStarArity + starArity, i.e. the number of patterns in the case definition

    Note that productArity is a function only of the extractor, and nonStar/star/totalArity are all functions of the patterns. The key value for aligning and typing the patterns is elementArity, as it is derived from both sets of information.

    If elementArity is...

    • zero: A perfect match between extractor and the fixed patterns. If there is a star pattern it will match any sequence.
    • positive: There are more patterns than products. There will have to be a sequence which can populate at least elementArity patterns.
    • negative: There are more products than patterns: compile time error.
    Definition Classes
    patmat
  • ExtractorAlignment
  • ExtractorSubPatternAlignment

class ExtractorAlignment extends ExtractorSubPatternAlignment

Source
PatternExpansion.scala
Linear Supertypes
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Inherited
  1. ExtractorAlignment
  2. ExtractorSubPatternAlignment
  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. Protected

Instance Constructors

  1. new ExtractorAlignment(fun: Global.Tree, args: List[Global.Tree])(context: Context)

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
    This member is added by an implicit conversion from ExtractorAlignment toany2stringadd[ExtractorAlignment] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ->[B](y: B): (ExtractorAlignment, B)
    Implicit
    This member is added by an implicit conversion from ExtractorAlignment toArrowAssoc[ExtractorAlignment] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()
  5. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  6. val args: List[Global.Tree]

    Args will be broken down into the concatenation of: productArity product patterns (fixed length, corresponding to fields in case class or tuple components in classic unapply, or product selectors in product-based unapply) elementArity element patterns (explicit patterns that pick off the prefix of the final sequence-valued component of the unapply, or a repeated case constructor arg) starArity star patterns (0 or 1, absorbs the remaining variable-length components)

    Args will be broken down into the concatenation of: productArity product patterns (fixed length, corresponding to fields in case class or tuple components in classic unapply, or product selectors in product-based unapply) elementArity element patterns (explicit patterns that pick off the prefix of the final sequence-valued component of the unapply, or a repeated case constructor arg) starArity star patterns (0 or 1, absorbs the remaining variable-length components)

    Definition Classes
    ExtractorAlignmentExtractorSubPatternAlignment
  7. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  8. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.CloneNotSupportedException]) @native()
  9. def elementArity: Int
  10. def ensuring(cond: (ExtractorAlignment) => Boolean, msg: => Any): ExtractorAlignment
    Implicit
    This member is added by an implicit conversion from ExtractorAlignment toEnsuring[ExtractorAlignment] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  11. def ensuring(cond: (ExtractorAlignment) => Boolean): ExtractorAlignment
    Implicit
    This member is added by an implicit conversion from ExtractorAlignment toEnsuring[ExtractorAlignment] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  12. def ensuring(cond: Boolean, msg: => Any): ExtractorAlignment
    Implicit
    This member is added by an implicit conversion from ExtractorAlignment toEnsuring[ExtractorAlignment] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  13. def ensuring(cond: Boolean): ExtractorAlignment
    Implicit
    This member is added by an implicit conversion from ExtractorAlignment toEnsuring[ExtractorAlignment] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  14. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  15. def equals(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef → Any
  16. def expectedExtractedType: Global.Type
  17. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.Throwable])
  18. def formatted(fmtstr: String): String
    Implicit
    This member is added by an implicit conversion from ExtractorAlignment toStringFormat[ExtractorAlignment] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @inline()
  19. val fun: Global.Tree
  20. final def getClass(): Class[_ <: AnyRef]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  21. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  22. def isBool: Boolean
  23. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  24. def isSeq: Boolean
  25. def isSingle: Boolean
  26. val isStar: Boolean
  27. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  28. val nonStarArity: Int
  29. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  30. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  31. def productArity: Int
  32. def resultInMonad(extractedBinder: Global.Symbol): Global.Type
  33. def starArity: Int
  34. def subPatTypes(extractedBinder: Global.Symbol): List[Global.Type]
  35. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  36. def toString(): String
    Definition Classes
    AnyRef → Any
  37. def totalArity: Int
  38. def unapplyFormals: List[Global.Type]
  39. def unapplySelector: Global.Symbol
  40. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  41. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  42. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException]) @native()

Deprecated Value Members

  1. def [B](y: B): (ExtractorAlignment, B)
    Implicit
    This member is added by an implicit conversion from ExtractorAlignment toArrowAssoc[ExtractorAlignment] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @deprecated
    Deprecated

    (Since version 2.13.0) Use -> instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd fromExtractorAlignment to any2stringadd[ExtractorAlignment]

Inherited by implicit conversion StringFormat fromExtractorAlignment to StringFormat[ExtractorAlignment]

Inherited by implicit conversion Ensuring fromExtractorAlignment to Ensuring[ExtractorAlignment]

Inherited by implicit conversion ArrowAssoc fromExtractorAlignment to ArrowAssoc[ExtractorAlignment]

Ungrouped