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
- Alphabetic
- By Inheritance
- MatchOptimization
- MatchAnalysis
- MatchApproximation
- ScalaLogic
- Logic
- TreeAndTypeAnalysis
- MatchTreeMaking
- Debugging
- MatchCodeGen
- Interface
- TreeDSL
- AnyRef
- Any
- by any2stringadd
- by StringFormat
- by Ensuring
- by ArrowAssoc
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- Public
- Protected
Type Members
- 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
- trait TypedSubstitution extends MatchMonadInterface
- Definition Classes
- Interface
- trait PropositionalLogic extends AnyRef
- Definition Classes
- Logic
- trait MatchAnalyzer extends MatchApproximator
- Definition Classes
- MatchAnalysis
- 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
- trait CodegenCore extends MatchMonadInterface
- Definition Classes
- MatchCodeGen
- trait OptimizedCodegen extends CodegenCore with TypedSubstitution with MatchMonadInterface
- Definition Classes
- MatchCodeGen
- trait CommonSubconditionElimination extends OptimizedCodegen with MatchApproximator
- trait MatchOptimizer extends OptimizedCodegen with SwitchEmission with CommonSubconditionElimination
- trait SwitchEmission extends TreeMakers with MatchMonadInterface
- final case class Suppression(suppressExhaustive: Boolean, suppressUnreachable: Boolean) extends Product with Serializable
- Definition Classes
- MatchTreeMaking
- trait TreeMakers extends TypedSubstitution with CodegenCore
- Definition Classes
- MatchTreeMaking
- trait TreesAndTypesDomain extends PropositionalLogic with CheckableTreeAndTypeAnalysis
- Definition Classes
- ScalaLogic
- trait CheckableTreeAndTypeAnalysis extends AnyRef
- Definition Classes
- TreeAndTypeAnalysis
Concrete Value Members
- object CODE
- Definition Classes
- TreeDSL
- object debug
- Definition Classes
- Debugging
- object vpmName
- Definition Classes
- Interface
- final def !=(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
- final def ##: Int
- Definition Classes
- AnyRef → Any
- def +(other: String): String
- Implicit
- This member is added by an implicit conversion from MatchOptimization toany2stringadd[MatchOptimization] performed by method any2stringadd in scala.Predef.
- Definition Classes
- any2stringadd
- def ->[B](y: B): (MatchOptimization, B)
- Implicit
- This member is added by an implicit conversion from MatchOptimization toArrowAssoc[MatchOptimization] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc
- Annotations
- @inline()
- final def ==(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
- def alignAcrossRows(xss: List[List[Any]], sep: String, lineSep: String = "\n"): String
- Definition Classes
- Logic
- final def asInstanceOf[T0]: T0
- Definition Classes
- Any
- def binderTypeImpliedByPattern(pat: Global.Tree, pt: Global.Type): Global.Type
Compute the type T implied for a value
v
matched by a patternpat
(with expected typept
).Compute the type T implied for a value
v
matched by a patternpat
(with expected typept
).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. E.g., incase x@Nil => x
, all we know aboutx
is that it satisfiesNil == x
, which could be anything. A type pattern with a literal type works the same as the corresponding literal pattern. A literal pattern with a Boolean or Unit pattern does enforce that the respective value (true
,false
,()
) was matched, so in those cases, the pattern type is assumed.The other patterns imply type tests, so we can safely deduce that the binder has the pattern's type when the pattern matches. Concretely, a literal, type pattern, a case class (the constructor's result type) or extractor (the unapply's argument type) all imply type tests.
See scala/bug#1503, scala/bug#5024: don't cast binders to types we're not sure they have
- Definition Classes
- TreeAndTypeAnalysis
- def clone(): AnyRef
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.CloneNotSupportedException]) @native()
- final def dealiasWiden(tp: Global.Type): Global.Type
- Attributes
- protected
- Definition Classes
- Interface
- def ensuring(cond: (MatchOptimization) => Boolean, msg: => Any): MatchOptimization
- Implicit
- This member is added by an implicit conversion from MatchOptimization toEnsuring[MatchOptimization] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
- def ensuring(cond: (MatchOptimization) => Boolean): MatchOptimization
- Implicit
- This member is added by an implicit conversion from MatchOptimization toEnsuring[MatchOptimization] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
- def ensuring(cond: Boolean, msg: => Any): MatchOptimization
- Implicit
- This member is added by an implicit conversion from MatchOptimization toEnsuring[MatchOptimization] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
- def ensuring(cond: Boolean): MatchOptimization
- Implicit
- This member is added by an implicit conversion from MatchOptimization toEnsuring[MatchOptimization] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
- final def eq(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
- def equals(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef → Any
- def equivalentTree(a: Global.Tree, b: Global.Tree): Boolean
- Definition Classes
- TreeAndTypeAnalysis
- def finalize(): Unit
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.Throwable])
- def formatted(fmtstr: String): String
- Implicit
- This member is added by an implicit conversion from MatchOptimization toStringFormat[MatchOptimization] performed by method StringFormat in scala.Predef.
- Definition Classes
- StringFormat
- Annotations
- @inline()
- final def getClass(): Class[_ <: AnyRef]
- Definition Classes
- AnyRef → Any
- Annotations
- @native()
- final def hasStableSymbol(p: Global.Tree): Boolean
- Attributes
- protected
- Definition Classes
- Interface
- def hashCode(): Int
- Definition Classes
- AnyRef → Any
- Annotations
- @native()
- def instanceOfTpImplies(tp: Global.Type, tpImplied: Global.Type): Boolean
- Definition Classes
- TreeAndTypeAnalysis
- final def isInstanceOf[T0]: Boolean
- Definition Classes
- Any
- final def mkFALSE: Global.Literal
- Attributes
- protected
- Definition Classes
- Interface
- final def mkTRUE: Global.Literal
- Attributes
- protected
- Definition Classes
- Interface
- final def ne(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
- final def notify(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native()
- final def notifyAll(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native()
- final def synchronized[T0](arg0: => T0): T0
- Definition Classes
- AnyRef
- def toString(): String
- Definition Classes
- AnyRef → Any
- final def wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- final def wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- final def wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException]) @native()
- object Suppression extends java.io.Serializable
- Definition Classes
- MatchTreeMaking
Deprecated Value Members
- def →[B](y: B): (MatchOptimization, B)
- Implicit
- This member is added by an implicit conversion from MatchOptimization toArrowAssoc[MatchOptimization] 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.
The Scala compiler and reflection APIs.