Is there a way to express 'infinite time'?

Question

I am using the Range class to represent a range of times. Now I want a range which represents any point after a given time.

I tried (DateTime.now .. nil), but the Range class doesn't allow objects of different classes to be endpoints of the same range. (Attempting to create a Range with this property results in ArgumentError: bad value for range.)

Is there an equivalent of infinity for time, i.e. Time.now + (1.0/0.0)? Or alternately, is there a way to get around the Range class's requirement that its min and max values be of the same class?

Answer 1

It's possible using DateTime::Infinity class:

future = DateTime.now..DateTime::Infinity.new
future.include?(1_000_000.years.from_now) #=> true

Answer 2

range = (Time.now.to_f .. Float::INFINITY)
range.include?(Time.now.to_f) # => true
sleep 1
range.include?(Time.now.to_f) # => true
range.include?(Float::INFINITY) # => true

Answer 3

When you need to represent infinite time, you could use an object from a different class, that you create yourself. Just implement the matching operator and any other methods you use, and then it can be used interchangeably with Range objects.

class TimeRange
    def initialize(min, max)
    ...
    end
end