Class scala.runtime.AbstractPartialFunction
abstract class AbstractPartialFunction[-T1, +R] extends (T1) ⇒ R with PartialFunction[T1, R]
Instance Constructors
new AbstractPartialFunction()
Abstract Value Members
abstract def isDefinedAt(x: T1): Boolean
Checks if a value is contained in the function's domain.
- x
the value to test
- returns
true, iffxis in the domain of this function,falseotherwise.
- Definition Classes
- PartialFunction
Concrete Value Members
final def !=(arg0: Any): Boolean
Test two objects for inequality.
- returns
trueif !(this == that), false otherwise.
- Definition Classes
- AnyRef → Any
final def ##(): Int
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
def +(other: String): String
- Implicit
- This member is added by an implicit conversion from AbstractPartialFunction[T1, R] to any2stringadd[AbstractPartialFunction[T1, R]] performed by method any2stringadd in scala.Predef.
- Definition Classes
- any2stringadd
def ->[B](y: B): (AbstractPartialFunction[T1, R], B)
- Implicit
- This member is added by an implicit conversion from AbstractPartialFunction[T1, R] to ArrowAssoc[AbstractPartialFunction[T1, R]] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc
- Annotations
- @inline()
final def ==(arg0: Any): Boolean
The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).
- returns
trueif the receiver object is equivalent to the argument;falseotherwise.
- Definition Classes
- AnyRef → Any
def andThen[C](k: (R) ⇒ C): PartialFunction[T1, C]
Composes this partial function with a transformation function that gets applied to results of this partial function.
- C
the result type of the transformation function.
- k
the transformation function
- returns
a partial function with the same domain as this partial function, which maps arguments
xtok(this(x)).
- Definition Classes
- PartialFunction → Function1
def apply(x: T1): R
Apply the body of this function to the argument.
- returns
the result of function application.
- Definition Classes
- AbstractPartialFunction → Function1
def applyOrElse[A1 <: T1, B1 >: R](x: A1, default: (A1) ⇒ B1): B1
Applies this partial function to the given argument when it is contained in the function domain. Applies fallback function where this partial function is not defined.
Note that expression pf.applyOrElse(x, default) is equivalent to
if(pf isDefinedAt x) pf(x) else default(x)
except that applyOrElse method can be implemented more efficiently. For all partial function literals the compiler generates an applyOrElse implementation which avoids double evaluation of pattern matchers and guards. This makes applyOrElse the basis for the efficient implementation for many operations and scenarios, such as:
-
combining partial functions into
orElse/andThen chains does not lead to excessive apply/isDefinedAt evaluation
lift and unlift do not evaluate source functions twice on each invocation
runWith allows efficient imperative-style combining of partial functions with conditionally applied actions For non-literal partial function classes with nontrivial isDefinedAt method it is recommended to override applyOrElse with custom implementation that avoids double isDefinedAt evaluation. This may result in better performance and more predictable behavior w.r.t. side effects.
- x
the function argument
- default
the fallback function
- returns
the result of this function or fallback function application.
- Definition Classes
- PartialFunction
- Since
2.10
final def asInstanceOf[T0]: 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
ClassCastExceptionif the receiver object is not an instance of the erasure of typeT0.
def clone(): AnyRef
Create a copy of the receiver object.
The default implementation of the clone method is platform dependent.
- returns
a copy of the receiver object.
def compose[A](g: (A) ⇒ T1): (A) ⇒ R
Composes two instances of Function1 in a new Function1, with this function applied last.
- A
the type to which function
gcan be applied- g
a function A => T1
- returns
a new function
fsuch thatf(x) == apply(g(x))
- Definition Classes
- Function1
- Annotations
- @unspecialized()
def ensuring(cond: (AbstractPartialFunction[T1, R]) ⇒ Boolean, msg: ⇒ Any): AbstractPartialFunction[T1, R]
- Implicit
- This member is added by an implicit conversion from AbstractPartialFunction[T1, R] to Ensuring[AbstractPartialFunction[T1, R]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
def ensuring(cond: (AbstractPartialFunction[T1, R]) ⇒ Boolean): AbstractPartialFunction[T1, R]
- Implicit
- This member is added by an implicit conversion from AbstractPartialFunction[T1, R] to Ensuring[AbstractPartialFunction[T1, R]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
def ensuring(cond: Boolean, msg: ⇒ Any): AbstractPartialFunction[T1, R]
- Implicit
- This member is added by an implicit conversion from AbstractPartialFunction[T1, R] to Ensuring[AbstractPartialFunction[T1, R]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
def ensuring(cond: Boolean): AbstractPartialFunction[T1, R]
- Implicit
- This member is added by an implicit conversion from AbstractPartialFunction[T1, R] to Ensuring[AbstractPartialFunction[T1, R]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
final def eq(arg0: AnyRef): Boolean
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
trueif the argument is a reference to the receiver object;falseotherwise.
- Definition Classes
- AnyRef
def equals(arg0: Any): Boolean
The equality method for reference types. Default implementation delegates to eq.
See also equals in scala.Any.
- returns
trueif the receiver object is equivalent to the argument;falseotherwise.
- Definition Classes
- AnyRef → Any
def finalize(): Unit
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[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws( classOf[java.lang.Throwable] )
- Note
not specified by SLS as a member of AnyRef
def formatted(fmtstr: String): String
Returns string formatted according to given format string. Format strings are as for String.format (@see java.lang.String.format).
- Implicit
- This member is added by an implicit conversion from AbstractPartialFunction[T1, R] to Predef.StringFormat[AbstractPartialFunction[T1, R]] performed by method StringFormat in scala.Predef.
- Definition Classes
- StringFormat
- Annotations
- @inline()
final def getClass(): Class[_]
Returns the runtime class representation of the object.
- returns
a class object corresponding to the runtime type of the receiver.
def hashCode(): Int
The hashCode method for reference types. See hashCode in scala.Any.
- returns
the hash code value for this object.
final def isInstanceOf[T0]: Boolean
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
trueif the receiver object is an instance of erasure of typeT0;falseotherwise.
- Definition Classes
- Any
def lift: (T1) ⇒ Option[R]
Turns this partial function into a plain function returning an Option result.
- returns
a function that takes an argument
xtoSome(this(x))ifthisis defined forx, and toNoneotherwise.
- Definition Classes
- PartialFunction
- See also
Function.unlift
final def ne(arg0: AnyRef): Boolean
Equivalent to !(this eq that).
- returns
trueif the argument is not a reference to the receiver object;falseotherwise.
- Definition Classes
- AnyRef
final def notify(): Unit
Wakes up a single thread that is waiting on the receiver object's monitor.
- Definition Classes
- AnyRef
- Annotations
- @native()
- Note
not specified by SLS as a member of AnyRef
final def notifyAll(): Unit
Wakes up all threads that are waiting on the receiver object's monitor.
- Definition Classes
- AnyRef
- Annotations
- @native()
- Note
not specified by SLS as a member of AnyRef
def orElse[A1 <: T1, B1 >: R](that: PartialFunction[A1, B1]): PartialFunction[A1, B1]
Composes this partial function with a fallback partial function which gets applied where this partial function is not defined.
- A1
the argument type of the fallback function
- B1
the result type of the fallback function
- that
the fallback function
- returns
a partial function which has as domain the union of the domains of this partial function and
that. The resulting partial function takesxtothis(x)wherethisis defined, and tothat(x)where it is not.
- Definition Classes
- PartialFunction
def runWith[U](action: (R) ⇒ U): (T1) ⇒ Boolean
Composes this partial function with an action function which gets applied to results of this partial function. The action function is invoked only for its side effects; its result is ignored.
Note that expression pf.runWith(action)(x) is equivalent to
if(pf isDefinedAt x) { action(pf(x)); true } else false
except that runWith is implemented via applyOrElse and thus potentially more efficient. Using runWith avoids double evaluation of pattern matchers and guards for partial function literals.
- action
the action function
- returns
a function which maps arguments
xtoisDefinedAt(x). The resulting function runsaction(this(x))wherethisis defined.
- Definition Classes
- PartialFunction
- Since
2.10
- See also
applyOrElse.
final def synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
- AnyRef
def toString(): String
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.
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
def →[B](y: B): (AbstractPartialFunction[T1, R], B)
- Implicit
- This member is added by an implicit conversion from AbstractPartialFunction[T1, R] to ArrowAssoc[AbstractPartialFunction[T1, R]] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc
© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.12.9/scala/runtime/AbstractPartialFunction.html
AbstractPartialFunctionreformulates all operations of its supertraitPartialFunctionin terms ofisDefinedAtandapplyOrElse.This allows more efficient implementations in many cases:
orElsemethod supports chainedorElsein linear time, and with no slow-down if theorElsepart is not needed.liftmethod helps to avoid double evaluation of pattern matchers & guards of partial function literals.This trait is used as a basis for implementation of all partial function literals.
2.10