class Reacto::Operations::Slice

Constants

TYPES

Public Class Methods

new(predicate, type: :after) click to toggle source
# File lib/reacto/operations/slice.rb, line 8
def initialize(predicate, type: :after)
  unless TYPES.include?(type)
    raise ArgumentError.new(
      "Type #{type} not supported. " \
      "Supported types are #{TYPES.join(', ')}"
    )
  end

  @type = type
  @predicate = predicate
end

Public Instance Methods

call(tracker) click to toggle source
# File lib/reacto/operations/slice.rb, line 20
def call(tracker)
  buffer = []

  behaviour = -> (val) do
    buffer << val if @type == :after

    if @predicate.call(val)
      tracker.on_value(Trackable.enumerable(buffer))
      buffer = []
    end

    buffer << val if @type == :before
  end

  error = -> (e) do
    tracker.on_value(Trackable.enumerable(buffer)) unless buffer.empty?
    tracker.on_error(e)
  end

  close = -> () do
    tracker.on_value(Trackable.enumerable(buffer)) unless buffer.empty?
    tracker.on_close
  end

  Subscriptions::OperationSubscription.new(
    tracker, value: behaviour, error: error, close: close
  )
end