This gem provides Enumerable#count_by(&block), take a block for compute key value and returns { key => count_of_key_in_the_collection }.

Add this line to your application's Gemfile:

gem 'count_by'

And then execute:

$ bundle

Or install it yourself as:

$ gem install count_by

[1, 1, 2, 3, 4, 5].count_by{|x| x % 3}
#=> {1=>3, 2=>2, 0=>1}

enum = [1, 1, 2, 3, 4, 5].count_by
#=> #<Enumerator: ...>
enum.each{|x| x % 3}
#=> {1=>3, 2=>2, 0=>1}

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

• Call count_by without a block returns Enumerator

• Initial release