ControlContext

This class represent a portion of computation that has a 'hole' in it. The class has the ability to compute state up until a certain point where the state has the A type. If this context is given a function of type A => B to move the state to the B type, then the entire computation can be completed resulting in a value of type C.

An Example:

val cc = new ControlContext[String, String, String](
    fun = { (f: String=>String, err: Exception => String) =>
      val updatedState =
        try f("State")
        catch {
          case e: Exception => err(e)
        }
      updatedState + "-Complete!"
    },
    x = null.asIntanceOf[String]
}
cc.foreach(_ + "-Continued")  // Results in "State-Continued-Complete!"

This class is used to transform calls to shift in the continuations package. Direct use and instantiation is possible, but usually reserved for advanced cases.

A context may either be trivial or non-trivial. A trivial context just has a state of type A. When completing the computation, it's only necessary to use the function of type A => B directly against the trivial value. A non-trivial value stores a computation around the state transformation of type A => B and cannot be short-circuited.

A: The type of the state currently held in the context.
B: The type of the transformed state needed to complete this computation.
C: The return type of the entire computation stored in this context.

Note: fun and x are allowed to be null.
See also: scala.util.continutations.shiftR

Linear Supertypes

Serializable, java.io.Serializable, AnyRef, Any

Instance Constructors

new ControlContext(fun: ((A) ⇒ B, (Exception) ⇒ B) ⇒ C, x: A)
fun
The captured computation so far. The type (A => B, Exception => B) => C is a function where:
- The first parameter A=>B represents the computation defined against the current state held in the ControlContext.
- The second parameter Exception => B represents a computation to perform if an exception is thrown from the first parameter's computation.
- The return value is the result of the entire computation contained in this ControlContext.
x
The current state stored in this context. Allowed to be null if the context is non-trivial.

Value Members

final def !=(arg0: Any): Boolean

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

Definition Classes
AnyRef → Any
final def ==(arg0: Any): Boolean

Definition Classes
AnyRef → Any
final def asInstanceOf[T0]: T0

Definition Classes
Any
def clone(): AnyRef

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( ... )
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] )
final def flatMap[A1, B1, C1 <: B](f: (A) ⇒ ControlContext[A1, B1, C1]): ControlContext[A1, B1, C]

Maps and flattens this ControlContext with another ControlContext generated from the current state.
Maps and flattens this ControlContext with another ControlContext generated from the current state.
A1
The new type of the contained state.
B1
The new type of the state after the stored continuation has executed.
C1
The result type of the nested ControlContext. Because the nested ControlContext is executed within the outer ControlContext, this type must >: B so that the resulting nested computation can be fed through the current continuation.
f
A transformation function from the current state to a nested ControlContext.
returns
The transformed ControlContext.

Annotations
@noinline()
Note
The resulting comuptation is still the type C.
final def flatMapCatch[A1 >: A, B1 <: B, C1 >: C <: B1](pf: PartialFunction[Exception, ControlContext[A1, B1, C1]]): ControlContext[A1, B1, C1]
final def foreach(f: (A) ⇒ B): C

Runs the computation against the state stored in this ControlContext.
Runs the computation against the state stored in this ControlContext.
f
the computation that modifies the current state of the context.

Note
This method could throw exceptions from the computations.
def foreachFull(f: (A) ⇒ B, g: (Exception) ⇒ B): C
val fun: ((A) ⇒ B, (Exception) ⇒ B) ⇒ C

The captured computation so far.
The captured computation so far. The type (A => B, Exception => B) => C is a function where:
- The first parameter A=>B represents the computation defined against the current state held in the ControlContext.
- The second parameter Exception => B represents a computation to perform if an exception is thrown from the first parameter's computation.
- The return value is the result of the entire computation contained in this ControlContext.
final def getClass(): Class[_]

Definition Classes
AnyRef → Any
final def getTrivialValue: A

returns
The current state value.
def hashCode(): Int

Definition Classes
AnyRef → Any
final def isInstanceOf[T0]: Boolean

Definition Classes
Any
final def isTrivial: Boolean

returns
true if this context only stores a state value and not any deferred computation.
final def map[A1](f: (A) ⇒ A1): ControlContext[A1, B, C]

Modifies the currently captured state in this ControlContext.
Modifies the currently captured state in this ControlContext.
A1
The new type of state in this context.
f
A transformation function on the current state of the ControlContext.
returns
The new ControlContext.

Annotations
@noinline()
final def mapFinally(f: () ⇒ Unit): ControlContext[A, B, C]
final def ne(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def notify(): Unit

Definition Classes
AnyRef
final def notifyAll(): Unit

Definition Classes
AnyRef
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( ... )
final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
val x: A

The current state stored in this context.
The current state stored in this context. Allowed to be null if the context is non-trivial.

final class ControlContext[+A, -B, +C] extends Serializable

Instance Constructors

new ControlContext(fun: ((A) ⇒ B, (Exception) ⇒ B) ⇒ C, x: A)

Value Members

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: Any): Boolean

final def asInstanceOf[T0]: T0

def clone(): AnyRef

final def eq(arg0: AnyRef): Boolean

def equals(arg0: Any): Boolean

def finalize(): Unit

final def flatMap[A1, B1, C1 <: B](f: (A) ⇒ ControlContext[A1, B1, C1]): ControlContext[A1, B1, C]

final def flatMapCatch[A1 >: A, B1 <: B, C1 >: C <: B1](pf: PartialFunction[Exception, ControlContext[A1, B1, C1]]): ControlContext[A1, B1, C1]

final def foreach(f: (A) ⇒ B): C

def foreachFull(f: (A) ⇒ B, g: (Exception) ⇒ B): C

val fun: ((A) ⇒ B, (Exception) ⇒ B) ⇒ C

final def getClass(): Class[_]

final def getTrivialValue: A

def hashCode(): Int

final def isInstanceOf[T0]: Boolean

final def isTrivial: Boolean

final def map[A1](f: (A) ⇒ A1): ControlContext[A1, B, C]

final def mapFinally(f: () ⇒ Unit): ControlContext[A, B, C]

final def ne(arg0: AnyRef): Boolean

final def notify(): Unit

final def notifyAll(): Unit

final def synchronized[T0](arg0: ⇒ T0): T0

def toString(): String

final def wait(): Unit

final def wait(arg0: Long, arg1: Int): Unit

final def wait(arg0: Long): Unit

val x: A

Inherited from Serializable

Inherited from java.io.Serializable

Inherited from AnyRef

Inherited from Any

Ungrouped