t

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. SI-7290)
Source
MatchOptimization.scala
Known Subclasses
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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

    Test two objects for inequality.

    Test two objects for inequality.

    returns

    true if !(this == that), false otherwise.

    Definition Classes
    AnyRef → Any
  5. final def ##(): Int

    Equivalent to x.hashCode except for boxed numeric types and null.

    Equivalent to x.hashCode except for boxed numeric types and null. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For null returns a hashcode where null.hashCode throws a NullPointerException.

    returns

    a hash value consistent with ==

    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

    The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).

    The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    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

    Cast the receiver object to be of type T0.

    Cast the receiver object to be of type T0.

    Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expression List(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.

    returns

    the receiver object.

    Definition Classes
    Any
    Exceptions thrown

    ClassCastException if the receiver object is not an instance of the erasure of type T0.

  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 SI-1503, SI-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

    Create a copy of the receiver object.

    Create a copy of the receiver object.

    The default implementation of the clone method is platform dependent.

    returns

    a copy of the receiver object.

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

    not specified by SLS as a member of AnyRef

  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

    Tests whether the argument (that) is a reference to the receiver object (this).

    Tests whether the argument (that) is a reference to the receiver object (this).

    The eq method implements an equivalence relation on non-null instances of AnyRef, and has three additional properties:

    • It is consistent: for any non-null instances x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false.
    • For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false.
    • null.eq(null) returns true.

    When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).

    returns

    true if the argument is a reference to the receiver object; false otherwise.

    Definition Classes
    AnyRef
  19. def equals(arg0: Any): Boolean

    The equality method for reference types.

    The equality method for reference types. Default implementation delegates to eq.

    See also equals in scala.Any.

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    Definition Classes
    AnyRef → Any
  20. def equivalentTree(a: Global.Tree, b: Global.Tree): Boolean
    Definition Classes
    TreeAndTypeAnalysis
  21. def finalize(): Unit

    Called by the garbage collector on the receiver object when there are no more references to the object.

    Called by the garbage collector on the receiver object when there are no more references to the object.

    The details of when and if the finalize method is invoked, as well as the interaction between finalize and non-local returns and exceptions, are all platform dependent.

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

    not specified by SLS as a member of AnyRef

  22. 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
    @inline()
  23. final def getClass(): Class[_]

    Returns the runtime class representation of the object.

    Returns the runtime class representation of the object.

    returns

    a class object corresponding to the runtime type of the receiver.

    Definition Classes
    AnyRef → Any
  24. final def hasStableSymbol(p: Global.Tree): Boolean
    Attributes
    protected
    Definition Classes
    Interface
  25. def hashCode(): Int

    The hashCode method for reference types.

    The hashCode method for reference types. See hashCode in scala.Any.

    returns

    the hash code value for this object.

    Definition Classes
    AnyRef → Any
  26. def instanceOfTpImplies(tp: Global.Type, tpImplied: Global.Type): Boolean
    Definition Classes
    TreeAndTypeAnalysis
  27. final def isInstanceOf[T0]: Boolean

    Test whether the dynamic type of the receiver object is T0.

    Test whether the dynamic type of the receiver object is T0.

    Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression 1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will return true. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.

    returns

    true if the receiver object is an instance of erasure of type T0; false otherwise.

    Definition Classes
    Any
  28. final def mkFALSE: Global.Literal
    Attributes
    protected
    Definition Classes
    Interface
  29. final def mkTRUE: Global.Literal
    Attributes
    protected
    Definition Classes
    Interface
  30. final def ne(arg0: AnyRef): Boolean

    Equivalent to !(this eq that).

    Equivalent to !(this eq that).

    returns

    true if the argument is not a reference to the receiver object; false otherwise.

    Definition Classes
    AnyRef
  31. final def notify(): Unit

    Wakes up a single thread that is waiting on the receiver object's monitor.

    Wakes up a single thread that is waiting on the receiver object's monitor.

    Definition Classes
    AnyRef
    Note

    not specified by SLS as a member of AnyRef

  32. final def notifyAll(): Unit

    Wakes up all threads that are waiting on the receiver object's monitor.

    Wakes up all threads that are waiting on the receiver object's monitor.

    Definition Classes
    AnyRef
    Note

    not specified by SLS as a member of AnyRef

  33. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  34. def toString(): String

    Creates a String representation of this object.

    Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.

    returns

    a String representation of the object.

    Definition Classes
    AnyRef → Any
  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): (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
  39. object Suppression extends Serializable
    Definition Classes
    MatchTreeMaking

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