abstract class JavaPartialFunction[A, B] extends AbstractPartialFunction[A, B]
Helper for implementing a *pure* partial function: it will possibly be
invoked multiple times for a single “application”, because its only abstract
method is used for both isDefinedAt() and apply(); the former is mapped to
isCheck == true
and the latter to isCheck == false
for those cases where
this is important to know.
Failure to match is signaled by throwing noMatch()
, i.e. not returning
normally (the exception used in this case is pre-allocated, hence not
that expensive).
new JavaPartialFunction<Object, String>() { public String apply(Object in, boolean isCheck) { if (in instanceof TheThing) { if (isCheck) return null; // to spare the expensive or side-effecting code return doSomethingWithTheThing((TheThing) in); } else { throw noMatch(); } } }
The typical use of partial functions from Akka looks like the following:
if (pf.isDefinedAt(x)) {
pf.apply(x);
}
i.e. it will first call JavaPartialFunction.apply(x, true)
and if that
does not throw noMatch()
it will continue with calling
JavaPartialFunction.apply(x, false)
.
- Source
- JavaAPI.scala
Linear Supertypes
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Inherited
- JavaPartialFunction
- AbstractPartialFunction
- PartialFunction
- Function1
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Implicitly
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- by Ensuring
- by ArrowAssoc
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Instance Constructors
- new JavaPartialFunction()
Abstract Value Members
Concrete Value Members
-
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 JavaPartialFunction[A, B] to any2stringadd[JavaPartialFunction[A, B]] performed by method any2stringadd in scala.Predef.
- Definition Classes
- any2stringadd
-
def
->[B](y: B): (JavaPartialFunction[A, B], B)
- Implicit
- This member is added by an implicit conversion from JavaPartialFunction[A, B] to ArrowAssoc[JavaPartialFunction[A, B]] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc
- Annotations
- @inline()
-
final
def
==(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
-
def
andThen[C](k: (B) ⇒ C): PartialFunction[A, C]
- Definition Classes
- PartialFunction → Function1
-
final
def
apply(x: A): B
- Definition Classes
- JavaPartialFunction → AbstractPartialFunction → Function1
-
final
def
applyOrElse[A1 <: A, B1 >: B](x: A1, default: (A1) ⇒ B1): B1
- Definition Classes
- JavaPartialFunction → PartialFunction
-
final
def
asInstanceOf[T0]: T0
- Definition Classes
- Any
-
def
clone(): AnyRef
- Attributes
- protected[java.lang]
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
def
compose[A](g: (A) ⇒ A): (A) ⇒ B
- Definition Classes
- Function1
- Annotations
- @unspecialized()
-
def
ensuring(cond: (JavaPartialFunction[A, B]) ⇒ Boolean, msg: ⇒ Any): JavaPartialFunction[A, B]
- Implicit
- This member is added by an implicit conversion from JavaPartialFunction[A, B] to Ensuring[JavaPartialFunction[A, B]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
def
ensuring(cond: (JavaPartialFunction[A, B]) ⇒ Boolean): JavaPartialFunction[A, B]
- Implicit
- This member is added by an implicit conversion from JavaPartialFunction[A, B] to Ensuring[JavaPartialFunction[A, B]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
def
ensuring(cond: Boolean, msg: ⇒ Any): JavaPartialFunction[A, B]
- Implicit
- This member is added by an implicit conversion from JavaPartialFunction[A, B] to Ensuring[JavaPartialFunction[A, B]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
def
ensuring(cond: Boolean): JavaPartialFunction[A, B]
- Implicit
- This member is added by an implicit conversion from JavaPartialFunction[A, B] to Ensuring[JavaPartialFunction[A, B]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
-
final
def
eq(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
-
def
equals(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
-
def
finalize(): Unit
- Attributes
- protected[java.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 JavaPartialFunction[A, B] to StringFormat[JavaPartialFunction[A, B]] performed by method StringFormat in scala.Predef.
- Definition Classes
- StringFormat
- Annotations
- @inline()
-
final
def
getClass(): Class[_]
- Definition Classes
- AnyRef → Any
-
def
hashCode(): Int
- Definition Classes
- AnyRef → Any
-
final
def
isDefinedAt(x: A): Boolean
- Definition Classes
- JavaPartialFunction → PartialFunction
-
final
def
isInstanceOf[T0]: Boolean
- Definition Classes
- Any
-
def
lift: (A) ⇒ scala.Option[B]
- Definition Classes
- PartialFunction
-
final
def
ne(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
-
final
def
notify(): Unit
- Definition Classes
- AnyRef
-
final
def
notifyAll(): Unit
- Definition Classes
- AnyRef
-
def
orElse[A1 <: A, B1 >: B](that: PartialFunction[A1, B1]): PartialFunction[A1, B1]
- Definition Classes
- PartialFunction
-
def
runWith[U](action: (B) ⇒ U): (A) ⇒ Boolean
- Definition Classes
- PartialFunction
-
final
def
synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
- AnyRef
-
def
toString(): String
- Definition Classes
- Function1 → AnyRef → Any
-
final
def
wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
final
def
wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
final
def
wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
def
→[B](y: B): (JavaPartialFunction[A, B], B)
- Implicit
- This member is added by an implicit conversion from JavaPartialFunction[A, B] to ArrowAssoc[JavaPartialFunction[A, B]] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc