EnumUtils

Functions for mixing and matching lazy, potentially infinite enumerables.

Installation

Add this line to your application's Gemfile:

gem 'enum_utils'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install enum_utils

Usage

EnumUtils.sorted_intersection

Given N consistently-sorted enums, return unique values that appear in at least [degree] number of different enums, preserving the global order, until all enums are depleted. By default a value must appear in all of them.

# 3 ascending enums
EnumUtils.sorted_intersection(
  [1,2].each,
  [2,3].each,
  [1,2,5].each
).to_a # => [2]

# 3 descending enums
EnumUtils.sorted_intersection(
  [2,1].each,
  [3,2].each,
  [5,2,1].each,
  compare: -> a, b { b <=> a } # reverse order comparison
).to_a # => [2]

# 3 ascending enums with degree 2
EnumUtils.sorted_intersection(
  [1,2].each,
  [2,3].each,
  [1,2,5].each,
  degree: 2
).to_a # => [1, 2]

EnumUtils.sorted_union

Given N consistently-sorted enums, return all their unique values while preserving their global order. If with_index: true is given, also return index of the enum in which the corresponding value was first seen.

# 3 ascending enums
EnumUtils.sorted_union(
  [1,2].each,
  [2,3].each,
  [1,2,5].each
).to_a # => [1,2,3,5]

# 3 descending enums
EnumUtils.sorted_union(
  [2,1].each,
  [3,2].each,
  [5,2,1].each,
  compare: -> a, b { b <=> a } # reverse order comparison
).to_a # => [5,3,2,1]

# 3 ascending enums with index
EnumUtils.sorted_union(
  [1,2].each,
  [2,3].each,
  [1,2,5].each,
  with_index: true
).to_a # => [[1,0], [2,0], [3,1], [5,2]]

EnumUtils.sorted_merge

Given N consistently-sorted enums, return all their values while preserving the global order. If with_index: true is given, also return index in the enum that originated the value.

## 3 ascending enums
EnumUtils.sorted_merge(
  [1,2].each,
  [2,3].each,
  [1,2,5].each
).to_a # => [1,1,2,2,2,3,5]

## 3 descending enums
EnumUtils.sorted_merge(
  [2,1].each,
  [3,2].each,
  [5,2,1].each,
  compare: -> a, b { b <=> a } # reverse order comparison
).to_a # => [5,3,2,2,2,1,1]

## 3 ascending enums with index
EnumUtils.sorted_union(
  [1,2].each,
  [2,3].each,
  [1,2,5].each,
  with_index: true
).to_a # => [[1,0], [1,2], [2,0], [2,1], [2,2], [3,1], [5,2]]

EnumUtils.round_robin

Given N enums, return all their values by taking one value from each enum in turn, until all are exhausted. If with_index: true is given, also return index of the enum that originated the value.

## 3 enums
EnumUtils.round_robin(
  [3,2].each,
  [1,3].each,
  [5,3,4].each
).to_a # => [3,1,5,2,3,3,4]

## 3 enums with index
EnumUtils.round_robin(
  [3,2].each,
  [1,3].each,
  [5,3,4].each,
  with_index: true
).to_a # => [[3,0], [1,1], [5,2], [2,0], [3,1], [3,2], [4,2]]

EnumUtils.concat

Given N enums, return a new enum which lazily exhausts every enum.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/maxim/enum_utils. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

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

Code of Conduct

Everyone interacting in the EnumUtils project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.