Module: IntervalNotation::Operations

Included in:
IntervalNotation
Defined in:
lib/interval_notation/operations.rb

Class Method Summary collapse

Class Method Details

.combine(interval_sets, combiner) ⇒ Object

Internal method which combines intervals according to an algorithm given by a combiner. Combiner tells whether current section or point should be included to a new interval.



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# File 'lib/interval_notation/operations.rb', line 9

def combine(interval_sets, combiner)
  points = interval_sets.each_with_index.flat_map{|interval_set, interval_set_index|
    interval_set.intervals.flat_map{|interval|
      interval.interval_boundaries(interval_set_index)
    }
  }.sort_by(&:value)

  intervals = []

  incl_from = nil
  from = nil

  points.chunk(&:value).each do |point_value, points_on_place|
    combiner.pass(points_on_place)

    if combiner.previous_state
      if combiner.state
        unless combiner.include_last_point
          intervals << BasicIntervals.interval_by_boundary_inclusion(incl_from, from, false, point_value)
          incl_from = false
          from = point_value
        end
      else
        to = point_value
        incl_to = combiner.include_last_point
        intervals << BasicIntervals.interval_by_boundary_inclusion(incl_from, from, incl_to, to)
        from = nil # easier to find an error (but not necessary code)
        incl_from = nil # ditto
      end
    else
      if combiner.state
        from = point_value
        incl_from = combiner.include_last_point
      else
        intervals << BasicIntervals::Point.new(point_value)  if combiner.include_last_point
      end
    end
  end
  IntervalSet.new_unsafe(intervals)
end

.intersection(intervals) ⇒ Object

Intersection of multiple intervals



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# File 'lib/interval_notation/operations.rb', line 56

def intersection(intervals)
  combine(intervals, IntersectCombiner.new(intervals.size))
end

.union(intervals) ⇒ Object

Union of multiple intervals.



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# File 'lib/interval_notation/operations.rb', line 51

def union(intervals)
  combine(intervals, UnionCombiner.new(intervals.size))
end