date_range_filter.rb

class DateRangeFilter
  def self.to_proc
    ->(constraint, events) { new(constraint, events).call }.to_proc
  end

  def initialize(constraint, events)
    @constraint = constraint
    @events = events
  end

  def call
    intersects_with_range?(constraint, other)
  end

  private

  # ...
end

#to_proc So obvious!