Rangops

Rangops is a tiny Ruby extension library that aims to treat Ranges as sets.

Install it with gem install rangops or add gem "rangops" to your Gemfile.

It patches Range class with methods for basic set related operations and predicates, like:

Union:

(1..5).union(3..10)
=> 1..10

(1..5) + (3..10)
=> 1..10

Intersection:

(1..5).intersection(3..10)
=> 3..5

(1..5) & (3..10)
=> 3..5

Symmetric difference:

(1..10).difference(5..15)
=> [1..5, 10..15]

(1..10) - (5..15)
=> [1..5, 10..15]

Relative complement:

(1..10).complement(5..15)
=> 10..15

Checking for subsets/supersets:

(2..3).subset?(0..10)
=> true

(0..10).superset?(2..3)
=> true

Check API docs for full list of aliases and predicates.

There is no mapping to arrays nor iteratons under the hood, just begin/end values comparison - so operations on ranges of any size are possible, with no penalty on speed or memory usage. Ranges delimited with any type of Numerics can be used.

(1.0..10).union(Rational(20, 4)..Float::INFINITY)
=> 1.0..Infinity 

Beginless and endless ranges are supported.

(nil..10).intersection(5..nil)
=> 5..10

(nil..10).union(5..nil)
=> nil..nil

End exclusion is supported too.

(1...3).intersect?(3..10)
=> false

It works well on string and date ranges too.

('2025-01-01'..'2026-12-31') & ('2026-01-01'..'2027-12-31')
=> '2026-01-01'..'2026-12-31'

('a'..'e') & ('c'..'g')
=> "c".."e"

Operations are supposed to return a Range result, so they only work on arguments delimited with values of the same type. (1..5) & ('c'..'g') will just return nil.

The gem is available as open source under the terms of the MIT License.