Spool

A spool is an asynchronous stream. It more or less mimics the scala {{Stream}} collection, but with cons cells that have deferred tails.

Construction is done with Spool.cons, Spool.empty. Convenience syntax like that of scala.Stream is provided. In order to use these operators for deconstruction, they must be imported explicitly ({{import Spool.{*::, **:: }}} )

def fill(rest: Promise[Spool[Int]]) {
  asyncProcess foreach { result =>
    if (result.last) {
      rest() = Return(result **:: Spool.empty)
    } else {
      val next = new Promise[Spool[Int]]
      rest() = Return(result *:: next)
      fill(next)
    }
  }
}
val rest = new Promise[Spool[Int]]
fill(rest)
firstElem *:: rest

explicitly ({{import Spool.{*::, **:: }}}

def fill(rest: Promise[Spool[Int]]) {
  asyncProcess foreach { result =>
    if (result.last) {
      rest() = Return(result **:: Spool.empty)
    } else {
      val next = new Promise[Spool[Int]]
      rest() = Return(result *:: next)
      fill(next)
    }
  }
}
val rest = new Promise[Spool[Int]]
fill(rest)
firstElem *:: rest

Linear Supertypes

AnyRef, Any

Known Subclasses

Cons, Empty

Abstract Value Members

abstract def collect[B](f: PartialFunction[A, B]): Future[Spool[B]]

The standard Scala collect, in order to implement map & filter.
The standard Scala collect, in order to implement map & filter.
It may seem unnatural to return a Future[…] here, but we cannot know whether the first element exists until we have applied its filter.
abstract def head: A

The first element of the spool.
The first element of the spool. Invalid for empty spools.
abstract def isEmpty: Boolean
abstract def tail: Future[Spool[A]]

The (deferred) tail of the spool.
The (deferred) tail of the spool. Invalid for empty spools.

Concrete Value Members

final def !=(arg0: AnyRef): Boolean

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

Definition Classes
Any
final def ##(): Int

Definition Classes
AnyRef → Any
def ++[B >: A](that: Future[Spool[B]]): Future[Spool[B]]

Concatenates two spools.
def ++[B >: A](that: Spool[B]): Spool[B]

Concatenates two spools.
final def ==(arg0: AnyRef): Boolean

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

Definition Classes
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 filter(f: (A) ⇒ Boolean): Future[Spool[A]]
def finalize(): Unit

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws()
def flatMap[B](f: (A) ⇒ Future[Spool[B]]): Future[Spool[B]]

Applies a function that generates a spool to each element in this spool, flattening the result into a single spool.
def foldLeft[B](z: B)(f: (B, A) ⇒ B): Future[B]
def foreach[B](f: (A) ⇒ B): Future[Unit]

Apply {{f}} for each item in the spool, until the end.
Apply {{f}} for each item in the spool, until the end. {{f}} is applied as the items become available.
def foreachElem[B](f: (Option[A]) ⇒ B): Future[Unit]

A version of {{foreach}} that wraps each element in an {{Option}}, terminating the stream (EOF) with {{None}}.
final def getClass(): Class[_]

Definition Classes
AnyRef → Any
def hashCode(): Int

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

Definition Classes
Any
def map[B](f: (A) ⇒ B): Spool[B]
final def ne(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def notify(): Unit

Definition Classes
AnyRef
final def notifyAll(): Unit

Definition Classes
AnyRef
def reduceLeft[B >: A](f: (B, A) ⇒ B): Future[B]
final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
AnyRef
def toSeq: Future[Seq[A]]

Fully buffer the spool to a {{Seq}}.
Fully buffer the spool to a {{Seq}}. The returned future is satisfied when the entire result is ready.
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()

sealed trait Spool[+A] extends AnyRef

Abstract Value Members

abstract def collect[B](f: PartialFunction[A, B]): Future[Spool[B]]

abstract def head: A

abstract def isEmpty: Boolean

abstract def tail: Future[Spool[A]]

Concrete Value Members

final def !=(arg0: AnyRef): Boolean

final def !=(arg0: Any): Boolean

final def ##(): Int

def ++[B >: A](that: Future[Spool[B]]): Future[Spool[B]]

def ++[B >: A](that: Spool[B]): Spool[B]

final def ==(arg0: AnyRef): Boolean

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 filter(f: (A) ⇒ Boolean): Future[Spool[A]]

def finalize(): Unit

def flatMap[B](f: (A) ⇒ Future[Spool[B]]): Future[Spool[B]]

def foldLeft[B](z: B)(f: (B, A) ⇒ B): Future[B]

def foreach[B](f: (A) ⇒ B): Future[Unit]

def foreachElem[B](f: (Option[A]) ⇒ B): Future[Unit]

final def getClass(): Class[_]

def hashCode(): Int

final def isInstanceOf[T0]: Boolean

def map[B](f: (A) ⇒ B): Spool[B]

final def ne(arg0: AnyRef): Boolean

final def notify(): Unit

final def notifyAll(): Unit

def reduceLeft[B >: A](f: (B, A) ⇒ B): Future[B]

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

def toSeq: Future[Seq[A]]

def toString(): String

final def wait(): Unit

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

final def wait(arg0: Long): Unit

Inherited from AnyRef

Inherited from Any

Ungrouped