liquid/lib/liquid/range_lookup.rb

module Liquid
  class RangeLookup
    def self.parse(start_markup, end_markup)
      start_obj = Expression.parse(start_markup)
      end_obj = Expression.parse(end_markup)
      if start_obj.respond_to?(:evaluate) || end_obj.respond_to?(:evaluate)
        new(start_obj, end_obj)
      else
        start_obj.to_i..end_obj.to_i
      end
    end

    def initialize(start_obj, end_obj)
      @start_obj = start_obj
      @end_obj = end_obj
    end

    def evaluate(context)
      context.evaluate(@start_obj).to_i..context.evaluate(@end_obj).to_i
    end
  end
end