Consumer

A consumer that immediately cancels its upstream after subscription.

A simple consumer that consumes all elements of the stream and then signals its completion.

Creates a Consumer out of the given function.

The function returns an Observer and takes as input:

a Scheduler for any asynchronous execution needs the returned observer might have
a Cancelable that can be used for concurrently canceling the stream (in addition to being able to return Stop from onNext)
a Callback that must be called to signal the final result, after the observer finished processing the stream, or an error if the processing finished in error

Value Params

f: is the input function with an injected Scheduler, Cancelable, Callback and that returns an Observer

A consumer that will produce a Notification of the first value received (onNext, onComplete or onError), after which the streaming gets cancelled.

OnNext will be signaled on the first onNext event if it happens and the streaming will be stopped by Stop.
OnComplete will be signaled if the stream was empty and thus completed without any onNext.
OnError will be signaled if the stream was completed in error before the first onNext happened.

Given a fold function and an initial state value, applies the fold function to every element of the stream and finally signaling the accumulated value.

Value Params

f: is the function that calculates a new state on each emitted value by the stream, for accumulating state
initial: is a lazy value that will be fed at first in the fold function as the initial state.

Given a fold function and an initial state value, applies the fold function to every element of the stream and finally signaling the accumulated value.

The given fold function returns an F[A] value, where F is any data type that implements cats.effect.Effect (e.g. Task, Coeval), thus able to do asynchronous processing, with ordering of calls being guaranteed.

Value Params

f: is the function that calculates a new state on each emitted value by the stream, for accumulating state, returning a F[A] capable of lazy or asynchronous execution.
initial: is a lazy value that will be fed at first in the fold function as the initial state.

Given a fold function and an initial state value, applies the fold function to every element of the stream and finally signaling the accumulated value.

The given fold function returns a Task that can execute an asynchronous operation, with ordering of calls being guaranteed.

Value Params

f: is the function that calculates a new state on each emitted value by the stream, for accumulating state, returning a Task capable of asynchronous execution.
initial: is a lazy value that will be fed at first in the fold function as the initial state.

Builds a consumer that will consume the stream, applying the given function to each element and then finally signaling its completion.

Value Params

cb: is the function that will be called for each element

Builds a consumer that will consume the stream, applying the given function to each element and then finally signaling its completion.

The given callback function returns a F[A] value that can execute an asynchronous operation, with ordering of calls being guaranteed, given that the F[_] data type is any type that implements cats.effect.Effect (e.g. Task, IO).

Value Params

cb: is the function that will be called for each element

Builds a consumer that will consume the stream, applying the given function to each element, in parallel, then finally signaling its completion.

Value Params

cb: is the function that will be called for each element
parallelism: is the maximum number of (logical) threads to use

Builds a consumer that will consume the stream, applying the given function to each element, in parallel, then finally signaling its completion.

The given callback function returns a Task that can execute an asynchronous operation, with ordering of calls being guaranteed per subscriber.

Value Params

cb: is the function that will be called for each element
parallelism: is the maximum number of (logical) threads to use

Builds a consumer that will consume the stream, applying the given function to each element and then finally signaling its completion.

The given callback function returns a Task that can execute an asynchronous operation, with ordering of calls being guaranteed.

Value Params

cb: is the function that will be called for each element

Given a function taking a Scheduler and returning an Observer, builds a consumer from it.

You can use the Scheduler as the execution context, for working with Future, for forcing asynchronous boundaries or for executing tasks with a delay.

A consumer that will produce the first streamed value on onNext after which the streaming gets cancelled.

In case the stream is empty and so no onNext happen before onComplete, then the a NoSuchElementException will get triggered.

A consumer that will produce the first streamed value on onNext after which the streaming gets cancelled.

In case the stream is empty and so no onNext happen before onComplete, then the a NoSuchElementException will get triggered.

Creates a consumer that, when consuming the stream, will start multiple subscribers corresponding and distribute the load between them.

   Once each subscriber emits a final result, this consumer will
   return a list of aggregated results.

   Has the following rules:

    - items are pushed on free subscribers, respecting their
      contract, each item being pushed to the first available
      subscriber in the queue
    - in case no free subscribers are available, then the
      source gets back-pressured until free subscribers are
      available
    - in case of `onComplete` or `onError`, all subscribers
      that are still active will receive the event
    - the `onSuccess` callback of individual subscribers is
      aggregated in a list buffer and once the aggregate contains
      results from all subscribers, the load-balancing consumer
      will emit the aggregate
    - the `onError` callback triggered by individual subscribers will
      signal that error upstream and cancel the streaming for
      every other subscriber
    - in case any of the subscribers cancels its subscription
      (either returning `Stop` in `onNext` or canceling its assigned
       cancelable), it gets excluded from the pool of active
      subscribers, but the other active subscribers will still
      receive notifications
    - if all subscribers canceled (either by returning `Stop`
      or by canceling their assignable cancelable reference),
      then streaming stops as well

   In other words the `Task`, created by applying this consumer to
   an observable, will complete once all the subscribers emit a result
   or as soon as an error happens.

Value Params

consumer: is the subscriber factory that will initialize all needed subscribers, in number equal to the specified parallelism and thus that will be fed in parallel
parallelism: is the number of subscribers that will get initialized to process incoming events in parallel.

Returns

a list of aggregated results that were computed by all of the subscribers as their result

Creates a consumer that, when consuming the stream, will start multiple subscribers corresponding and distribute the load between them.

   Once each subscriber emits a final result, this consumer will
   return a list of aggregated results.

   Has the following rules:

    - items are pushed on free subscribers, respecting their
      contract, each item being pushed to the first available
      subscriber in the queue
    - in case no free subscribers are available, then the
      source gets back-pressured until free subscribers are
      available
    - in case of `onComplete` or `onError`, all subscribers
      that are still active will receive the event
    - the `onSuccess` callback of individual subscribers is
      aggregated in a list buffer and once the aggregate contains
      results from all subscribers, the load-balancing consumer
      will emit the aggregate
    - the `onError` callback triggered by individual subscribers will
      signal that error upstream and cancel the streaming for
      every other subscriber
    - in case any of the subscribers cancels its subscription
      (either returning `Stop` in `onNext` or canceling its assigned
       cancelable), it gets excluded from the pool of active
      subscribers, but the other active subscribers will still
      receive notifications
    - if all subscribers canceled (either by returning `Stop`
      or by canceling their assignable cancelable reference),
      then streaming stops as well

   In other words the `Task`, created by applying this consumer to
   an observable, will complete once all the subscribers emit a result
   or as soon as an error happens.

Value Params

consumers: is a list of consumers that will initialize the subscribers that will process events in parallel, with the parallelism factor being equal to the number of consumers specified in this list.

Returns

a list of aggregated results that were computed by all of the subscribers as their result

A consumer that triggers an error and immediately cancels its upstream after subscription.

A consumer that will return a collection of all the streamed values as a Scala List.

Note that this method is functionally the same as the Observable.toListL

WARNING: For infinite streams the process will eventually blow up with an out of memory error.

Consumer

Type members

Classlikes

Value members

Concrete methods

Implicits

Implicits