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author | Martin Odersky <odersky@gmail.com> | 2011-11-24 09:25:00 +0000 |
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committer | Martin Odersky <odersky@gmail.com> | 2011-11-24 09:25:00 +0000 |
commit | 5fb26c6a889cf1609823338df8783bf880769b3f (patch) | |
tree | 652d5c036465b669dc09039392ce79ab8f4b7759 /src/library | |
parent | 32a753546e0f7ef30e3e9c08b39a503ea93bc95a (diff) | |
download | scala-5fb26c6a889cf1609823338df8783bf880769b3f.tar.gz scala-5fb26c6a889cf1609823338df8783bf880769b3f.tar.bz2 scala-5fb26c6a889cf1609823338df8783bf880769b3f.zip |
Fast PartialFunction # orElse.
Diffstat (limited to 'src/library')
-rw-r--r-- | src/library/scala/Function.scala | 2 | ||||
-rw-r--r-- | src/library/scala/PartialFunction.scala | 7 | ||||
-rw-r--r-- | src/library/scala/runtime/AbstractPartialFunction.scala | 24 | ||||
-rw-r--r-- | src/library/scala/util/control/Exception.scala | 2 |
4 files changed, 21 insertions, 14 deletions
diff --git a/src/library/scala/Function.scala b/src/library/scala/Function.scala index f1e93d6c76..4a10b65735 100644 --- a/src/library/scala/Function.scala +++ b/src/library/scala/Function.scala @@ -41,7 +41,7 @@ object Function { */ def unlift[T, R](f: T => Option[R]): PartialFunction[T, R] = new runtime.AbstractPartialFunction[T, R] { def apply(x: T): R = f(x).get - def isDefinedAt(x: T): Boolean = f(x).isDefined + def _isDefinedAt(x: T): Boolean = f(x).isDefined override def lift: T => Option[R] = f } diff --git a/src/library/scala/PartialFunction.scala b/src/library/scala/PartialFunction.scala index 254a610648..b2910c2278 100644 --- a/src/library/scala/PartialFunction.scala +++ b/src/library/scala/PartialFunction.scala @@ -41,7 +41,7 @@ trait PartialFunction[-A, +B] extends (A => B) { */ def orElse[A1 <: A, B1 >: B](that: PartialFunction[A1, B1]) : PartialFunction[A1, B1] = new runtime.AbstractPartialFunction[A1, B1] { - def isDefinedAt(x: A1): Boolean = + def _isDefinedAt(x: A1): Boolean = PartialFunction.this.isDefinedAt(x) || that.isDefinedAt(x) def apply(x: A1): B1 = if (PartialFunction.this.isDefinedAt(x)) PartialFunction.this.apply(x) @@ -59,7 +59,7 @@ trait PartialFunction[-A, +B] extends (A => B) { * arguments `x` to `k(this(x))`. */ override def andThen[C](k: B => C) : PartialFunction[A, C] = new runtime.AbstractPartialFunction[A, C] { - def isDefinedAt(x: A): Boolean = PartialFunction.this.isDefinedAt(x) + def _isDefinedAt(x: A): Boolean = PartialFunction.this.isDefinedAt(x) def apply(x: A): C = k(PartialFunction.this.apply(x)) } @@ -90,7 +90,8 @@ trait PartialFunction[-A, +B] extends (A => B) { */ object PartialFunction { private[this] final val empty_pf: PartialFunction[Any, Nothing] = new runtime.AbstractPartialFunction[Any, Nothing] { - def isDefinedAt(x: Any) = false + def _isDefinedAt(x: Any) = false + override def isDefinedAt(x: Any) = false def apply(x: Any): Nothing = throw new MatchError(x) override def orElse[A1, B1](that: PartialFunction[A1, B1]): PartialFunction[A1, B1] = that override def orElseFast[A1, B1](that: PartialFunction[A1, B1]): PartialFunction[A1, B1] = that diff --git a/src/library/scala/runtime/AbstractPartialFunction.scala b/src/library/scala/runtime/AbstractPartialFunction.scala index b188cbb37d..f48d99f5af 100644 --- a/src/library/scala/runtime/AbstractPartialFunction.scala +++ b/src/library/scala/runtime/AbstractPartialFunction.scala @@ -23,24 +23,30 @@ abstract class AbstractPartialFunction[-T1, +R] with PartialFunction[T1, R] with Cloneable { - private var fallBack: PartialFunction[T1 @uncheckedVariance, R @uncheckedVariance] = PartialFunction.empty + private var fallBackField: PartialFunction[T1 @uncheckedVariance, R @uncheckedVariance] = _ - override protected def missingCase(x: T1): R = synchronized { - fallBack(x) + def fallBack: PartialFunction[T1, R] = synchronized { + if (fallBackField == null) fallBackField = PartialFunction.empty + fallBackField } + override protected def missingCase(x: T1): R = fallBack(x) + // Question: Need to ensure that fallBack is overwritten before any access // Is the `synchronized` here the right thing to achieve this? // Is there a cheaper way? - override def orElseFast[A1 <: T1, B1 >: R](that: PartialFunction[A1, B1]) : PartialFunction[A1, B1] = { + override def orElse[A1 <: T1, B1 >: R](that: PartialFunction[A1, B1]) : PartialFunction[A1, B1] = { val result = this.clone.asInstanceOf[AbstractPartialFunction[A1, B1]] result.synchronized { - result.fallBack = this.fallBack orElseFast that + result.fallBackField = this.fallBackField orElse that result } } -/* - def isDefinedAt(x: T1): scala.Boolean = isDefinedAtCurrent(x) || fallBack.isDefinedAt(x) - def isDefinedAtCurrent(x: T1): scala.Boolean = false -*/ + + def isDefinedAt(x: T1): scala.Boolean = _isDefinedAt(x) || fallBack.isDefinedAt(x) + def _isDefinedAt(x: T1): scala.Boolean + } + + + diff --git a/src/library/scala/util/control/Exception.scala b/src/library/scala/util/control/Exception.scala index 5fc938d18c..5e3f8b6451 100644 --- a/src/library/scala/util/control/Exception.scala +++ b/src/library/scala/util/control/Exception.scala @@ -232,6 +232,6 @@ object Exception { private def pfFromExceptions(exceptions: Class[_]*): PartialFunction[Throwable, Nothing] = new scala.runtime.AbstractPartialFunction[Throwable, Nothing] { def apply(x: Throwable) = throw x - def isDefinedAt(x: Throwable) = wouldMatch(x, exceptions) + def _isDefinedAt(x: Throwable) = wouldMatch(x, exceptions) } } |