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scala.tools.nsc.transform.patmat

MatchOptimization

trait MatchOptimization extends MatchTreeMaking with MatchAnalysis

Optimize and analyze matches based on their TreeMaker-representation.

The patmat translation doesn't rely on this, so it could be disabled in principle.

  • well, not quite: the backend crashes if we emit duplicates in switches (e.g. scala/bug#7290)
Source
MatchOptimization.scala
Known Subclasses
Ordering
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Inherited
  1. MatchOptimization
  2. MatchAnalysis
  3. MatchApproximation
  4. ScalaLogic
  5. Logic
  6. TreeAndTypeAnalysis
  7. MatchTreeMaking
  8. Debugging
  9. MatchCodeGen
  10. Interface
  11. TreeDSL
  12. AnyRef
  13. 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. trait MatchMonadInterface extends AnyRef

    Interface with user-defined match monad? if there's a __match in scope, we use this as the match strategy, assuming it conforms to MatchStrategy as defined below:

    Interface with user-defined match monad? if there's a __match in scope, we use this as the match strategy, assuming it conforms to MatchStrategy as defined below:

    type Matcher[P[_], M[+_], A] = {
      def flatMap[B](f: P[A] => M[B]): M[B]
      def orElse[B >: A](alternative: => M[B]): M[B]
    }
    
    abstract class MatchStrategy[P[_], M[+_]] {
      // runs the matcher on the given input
      def runOrElse[T, U](in: P[T])(matcher: P[T] => M[U]): P[U]
    
      def zero: M[Nothing]
      def one[T](x: P[T]): M[T]
      def guard[T](cond: P[Boolean], then: => P[T]): M[T]
    }

    P and M are derived from one's signature (def one[T](x: P[T]): M[T])

    if no __match is found, we assume the following implementation (and generate optimized code accordingly)

    object __match extends MatchStrategy[({type Id[x] = x})#Id, Option] {
      def zero = None
      def one[T](x: T) = Some(x)
      // NOTE: guard's return type must be of the shape M[T], where M is the monad in which the pattern match should be interpreted
      def guard[T](cond: Boolean, then: => T): Option[T] = if(cond) Some(then) else None
      def runOrElse[T, U](x: T)(f: T => Option[U]): U = f(x) getOrElse (throw new MatchError(x))
    }
    Definition Classes
    Interface
  2. trait TypedSubstitution extends MatchMonadInterface
    Definition Classes
    Interface
  3. trait PropositionalLogic extends AnyRef
    Definition Classes
    Logic
  4. trait MatchAnalyzer extends MatchApproximator
    Definition Classes
    MatchAnalysis
  5. trait MatchApproximator extends TreeMakers with TreesAndTypesDomain

    Represent a match as a formula in propositional logic that encodes whether the match matches (abstractly: we only consider types)

    Represent a match as a formula in propositional logic that encodes whether the match matches (abstractly: we only consider types)

    Definition Classes
    MatchApproximation
  6. trait CodegenCore extends MatchMonadInterface
    Definition Classes
    MatchCodeGen
  7. trait OptimizedCodegen extends CodegenCore with TypedSubstitution with MatchMonadInterface
    Definition Classes
    MatchCodeGen
  8. trait PureCodegen extends CodegenCore with PureMatchMonadInterface
    Definition Classes
    MatchCodeGen
  9. trait PureMatchMonadInterface extends MatchMonadInterface
    Definition Classes
    MatchCodeGen
  10. trait CommonSubconditionElimination extends OptimizedCodegen with MatchApproximator
  11. trait MatchOptimizer extends OptimizedCodegen with SwitchEmission with CommonSubconditionElimination
  12. trait SwitchEmission extends TreeMakers with MatchMonadInterface
  13. final case class Suppression(suppressExhaustive: Boolean, suppressUnreachable: Boolean) extends Product with Serializable
    Definition Classes
    MatchTreeMaking
  14. trait TreeMakers extends TypedSubstitution with CodegenCore
    Definition Classes
    MatchTreeMaking
  15. trait TreesAndTypesDomain extends PropositionalLogic with CheckableTreeAndTypeAnalysis
    Definition Classes
    ScalaLogic
  16. trait CheckableTreeAndTypeAnalysis extends AnyRef
    Definition Classes
    TreeAndTypeAnalysis

Abstract Value Members

  1. abstract val global: Global
    Definition Classes
    Debugging

Concrete Value Members

  1. object CODE
    Definition Classes
    TreeDSL
  2. object debug
    Definition Classes
    Debugging
  3. object vpmName
    Definition Classes
    Interface
  4. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  5. final def ##(): Int
    Definition Classes
    AnyRef → Any
  6. def +(other: String): String
    Implicit
    This member is added by an implicit conversion from MatchOptimization to any2stringadd[MatchOptimization] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  7. def ->[B](y: B): (MatchOptimization, B)
    Implicit
    This member is added by an implicit conversion from MatchOptimization to ArrowAssoc[MatchOptimization] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()
  8. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  9. def alignAcrossRows(xss: List[List[Any]], sep: String, lineSep: String = "\n"): String
    Definition Classes
    Logic
  10. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  11. def binderTypeImpliedByPattern(pat: Global.Tree, pt: Global.Type, binder: Global.Symbol): Global.Type

    Compute the type T implied for a value v matched by a pattern pat (with expected type pt).

    Compute the type T implied for a value v matched by a pattern pat (with expected type pt).

    Usually, this is the pattern's type because pattern matching implies instance-of checks.

    However, Stable Identifier and Literal patterns are matched using ==, which does not imply a type for the binder that binds the matched value.

    See scala/bug#1503, scala/bug#5024: don't cast binders to types we're not sure they have

    TODO: update spec as follows (deviation between **):

    A pattern binder x@p consists of a pattern variable x and a pattern p. The type of the variable x is the static type T **IMPLIED BY** the pattern p. This pattern matches any value v matched by the pattern p **Deleted: , provided the run-time type of v is also an instance of T, ** and it binds the variable name to that value.

    Addition: A pattern p _implies_ a type T if the pattern matches only values of the type T.

    Definition Classes
    TreeAndTypeAnalysis
  12. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  13. final def dealiasWiden(tp: Global.Type): Global.Type
    Attributes
    protected
    Definition Classes
    Interface
  14. def ensuring(cond: (MatchOptimization) ⇒ Boolean, msg: ⇒ Any): MatchOptimization
    Implicit
    This member is added by an implicit conversion from MatchOptimization to Ensuring[MatchOptimization] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  15. def ensuring(cond: (MatchOptimization) ⇒ Boolean): MatchOptimization
    Implicit
    This member is added by an implicit conversion from MatchOptimization to Ensuring[MatchOptimization] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  16. def ensuring(cond: Boolean, msg: ⇒ Any): MatchOptimization
    Implicit
    This member is added by an implicit conversion from MatchOptimization to Ensuring[MatchOptimization] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  17. def ensuring(cond: Boolean): MatchOptimization
    Implicit
    This member is added by an implicit conversion from MatchOptimization to Ensuring[MatchOptimization] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  18. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  19. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  20. def equivalentTree(a: Global.Tree, b: Global.Tree): Boolean
    Definition Classes
    TreeAndTypeAnalysis
  21. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  22. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  23. final def hasStableSymbol(p: Global.Tree): Boolean
    Attributes
    protected
    Definition Classes
    Interface
  24. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  25. def instanceOfTpImplies(tp: Global.Type, tpImplied: Global.Type): Boolean
    Definition Classes
    TreeAndTypeAnalysis
  26. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  27. final def mkFALSE: Global.Literal
    Attributes
    protected
    Definition Classes
    Interface
  28. final def mkTRUE: Global.Literal
    Attributes
    protected
    Definition Classes
    Interface
  29. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  30. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  31. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  32. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  33. def toString(): String
    Definition Classes
    AnyRef → Any
  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( ... ) @native()
  37. def [B](y: B): (MatchOptimization, B)
    Implicit
    This member is added by an implicit conversion from MatchOptimization to ArrowAssoc[MatchOptimization] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
  38. object Suppression extends Serializable
    Definition Classes
    MatchTreeMaking

Deprecated Value Members

  1. def formatted(fmtstr: String): String
    Implicit
    This member is added by an implicit conversion from MatchOptimization to StringFormat[MatchOptimization] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @deprecated @inline()
    Deprecated

    (Since version 2.12.16) Use formatString.format(value) instead of value.formatted(formatString), or use the f"" string interpolator. In Java 15 and later, formatted resolves to the new method in String which has reversed parameters.

Inherited from MatchAnalysis

Inherited from MatchApproximation

Inherited from ScalaLogic

Inherited from Logic

Inherited from TreeAndTypeAnalysis

Inherited from MatchTreeMaking

Inherited from Debugging

Inherited from MatchCodeGen

Inherited from Interface

Inherited from TreeDSL

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd from MatchOptimization to any2stringadd[MatchOptimization]

Inherited by implicit conversion StringFormat from MatchOptimization to StringFormat[MatchOptimization]

Inherited by implicit conversion Ensuring from MatchOptimization to Ensuring[MatchOptimization]

Inherited by implicit conversion ArrowAssoc from MatchOptimization to ArrowAssoc[MatchOptimization]

Ungrouped