FriendlyRange makes it easy to parse and compose ranges of numbers in a human friendly way.
It allows you to easily accept multiple ranges as input, like 1-4, 9, 15-19. Just make sure ranges use hyphens and commas.
Add to your Gemfile:
gem 'friendlyrange'
Or install manually:
$ gem install friendlyrange
To parse a human-input range of numbers:
range = FriendlyRange.new('1-4, 9, 11-13')
Now just use the range as an array:
range.to_a
# => [1, 2, 3, 4, 9, 11, 12, 13]
Or, you can transform it back to a string:
range.to_s
# => "1-4, 9, 11-13"
You can even take ranges in weird orders:
range = FriendlyRange.new('5-9, 1, 3')
range.to_a
# => [1, 3, 5, 6, 7, 8, 9]
range.to_s
# => "1, 3, 5-9"
It will even reconcile "bad" input, with overlapping numbers. It will deduplicate any numbers automatically.
range = FriendlyRange.new('1, 1-4, 4')
range.to_a
# => [1, 2, 3, 4]
range.to_s
#=> "1-4"
It will also compensate for crap input. Human friendly!
range = FriendlyRange.new('1 - 4 , 8- 9 , 10')
range.to_a
# => [1, 2, 3, 4, 8, 9, 10]
range.to_s
# => "1-4, 8-10"
I'd love any feedback. Just file an issue or pull request. Please make sure any pull requests have tests for whatever you've changed.