stages-pages
API
Generated with
stages-pages/h8io.stages/h8io.stages.operators/Lift

Lift

h8io.stages.operators.Lift
final case class Lift[I, O, E](alterand: Stage[I, O, E]) extends Alterator[Stage[I, O, E], I, Option[O], E], Fruitful[I, Option[O], E]

A decorator that wraps a stage's optional output into an Option, making the result always present.

  • If the inner stage yields h8io.stages.Yield.Some``(v, ...), Lift produces h8io.stages.Yield.Some``(Some(v), ...).
  • If the inner stage yields h8io.stages.Yield.None``(...), Lift produces h8io.stages.Yield.Some``(None, ...).

Because Lift always emits a value, it extends h8io.stages.base.Fruitful. The evolution of the result is mapped so that every continuation stage is also wrapped in Lift, preserving the lifting semantics across the entire pipeline.

Lift is the inverse of h8io.stages.projections.Unlift.

Type parameters

E

the error type

I

the input type

O

the inner output type; the outer output type becomes Option[O]

Value parameters

alterand

the inner stage whose output is optionally present

Attributes

Graph
Supertypes
trait Serializable
trait Product
trait Equals
trait Fruitful[I, Option[O], E]
trait Alterator[Stage[I, O, E], I, Option[O], E]
trait Stage[I, Option[O], E]
trait I => Yield[I, Option[O], E]
class Object
trait Matchable
class Any
Show all

Members list

Value members

Concrete methods

override def apply(in: I): Some[I, Option[O], E]

Processes in and returns the Yield carrying the optional output, the status and the continuation.

Processes in and returns the Yield carrying the optional output, the status and the continuation.

A stage that throws from here must have released its own resources first — see the ''Lifecycle'' section above.

Attributes

Definition Classes
Fruitful -> Stage -> Function1
override def skip(): Evolution[I, Option[O], E]

Returns this stage's Evolution without consuming an input.

Returns this stage's Evolution without consuming an input.

Called instead of apply whenever the stage takes part in a run but has nothing to process: the upstream yielded no output, or a binary operator excluded this branch. The evolution must be the one the stage would have returned had it run. Like apply, skip() may perform side effects — a decorator, for instance, may advance or release the inner stage it owns.

Attributes

Definition Classes

Inherited methods

def andThen[A](g: Yield[I, Option[O], E] => A): I => A

Composes two instances of Function1 in a new Function1, with this function applied first.

Composes two instances of Function1 in a new Function1, with this function applied first.

Type parameters

A

the result type of function g

Value parameters

g

a function R => A

Attributes

Returns

a new function f such that f(x) == g(apply(x))

Inherited from:
Function1
def compose[A](g: A => I): A => Yield[I, Option[O], E]

Composes two instances of Function1 in a new Function1, with this function applied last.

Composes two instances of Function1 in a new Function1, with this function applied last.

Type parameters

A

the type to which function g can be applied

Value parameters

g

a function A => T1

Attributes

Returns

a new function f such that f(x) == apply(g(x))

Inherited from:
Function1
def productElementNames: Iterator[String]

An iterator over the names of all the elements of this product.

An iterator over the names of all the elements of this product.

Attributes

Inherited from:
Product
def productIterator: Iterator[Any]

An iterator over all the elements of this product.

An iterator over all the elements of this product.

Attributes

Returns

in the default implementation, an Iterator[Any]

Inherited from:
Product
override def toString(): String

Returns a string representation of the object.

Returns a string representation of the object.

The default representation is platform dependent.

Attributes

Returns

a string representation of the object.

Definition Classes
Function1 -> Any
Inherited from:
Function1
final def ~>[_O, _E >: E](that: Stage[Option[O], _O, _E]): Stage[I, _O, _E]

Composes this stage with that, feeding this stage's output into it. See the ''Composition'' section above for what happens when there is no output to feed.

Composes this stage with that, feeding this stage's output into it. See the ''Composition'' section above for what happens when there is no output to feed.

Attributes

Inherited from:
Stage
Generated with