FoldState

A FoldState defines a left fold with a "hidden" accumulator type. It is exposed so library authors can run Folds over their own sequence types.

The fold can be executed correctly according to the properties of "add" and your traversed data structure. For example, the "add" function of a monoidal fold will be associative. A FoldState is valid for only one iteration because the accumulator (seeded by "start" may be mutable.

The three components of a fold are add: (X, I) => X - updates and returns internal state for every input I start: X - the initial state end: X => O - transforms internal state to a final result

Folding over Seq(x, y) would produce the result end(add(add(start, x), y))

Linear Supertypes

Serializable, AnyRef, Any

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
val add: (X, I) ⇒ X
final def asInstanceOf[T0]: T0

Definition Classes
Any
def clone(): AnyRef

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( ... )
def contramap[H](f: (H) ⇒ I): FoldState[X, H, O]

Transforms the input type of the FoldState (see Fold.contramap).
val end: (X) ⇒ O
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 getClass(): Class[_]

Definition Classes
AnyRef → Any
def hashCode(): Int

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

Definition Classes
Any
def map[P](f: (O) ⇒ P): FoldState[X, I, P]

Transforms the output type of the FoldState (see Fold.map).
final def ne(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def notify(): Unit

Definition Classes
AnyRef
final def notifyAll(): Unit

Definition Classes
AnyRef
val start: X
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( ... )

Related Doc: package algebird

final class FoldState[X, -I, +O] extends Serializable

Value Members

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: Any): Boolean

val add: (X, I) ⇒ X

final def asInstanceOf[T0]: T0

def clone(): AnyRef

def contramap[H](f: (H) ⇒ I): FoldState[X, H, O]

val end: (X) ⇒ O

final def eq(arg0: AnyRef): Boolean

def equals(arg0: Any): Boolean

def finalize(): Unit

final def getClass(): Class[_]

def hashCode(): Int

final def isInstanceOf[T0]: Boolean

def map[P](f: (O) ⇒ P): FoldState[X, I, P]

final def ne(arg0: AnyRef): Boolean

final def notify(): Unit

final def notifyAll(): Unit

val start: X

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

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

Ungrouped