README.md
# Haversack
[](https://travis-ci.org/alex0112/haversack) [](https://codeclimate.com/github/alex0112/haversack/maintainability)
Haversack is an enumerable abstraction of a [Knapsack](https://en.wikipedia.org/wiki/Knapsack_problem). Itis a proof of concept for a knapsack data structure, used for projects [like this one](https://rollout.io/blog/using-genetic-algorithms-in-ruby/).
## Basic Usage:
```ruby
require 'haversack'
haversack = Sack.new(capacity: 10, weight: 10)
items = Array.new(10) { Haversack::Item.new(weight: 1, size: 1) }
haversack.contents = items
## Haversack provides constraints upon what items may be set as the knapsack contents:
too_large = Array.new(haversack.capacity + 1) { Haversack::Item.new }
haversack.contents = too_large # => Haversack::KnapsackCapacityExceededError
## Or you may add one item at a time
item = Haversack::Item.new
haversack.push(item) if haversack.fits_item? item
```
## Installation
Add this line to your application's Gemfile:
```ruby
gem 'haversack'
```
And then execute:
$ bundle
Or install it yourself as:
$ gem install haversack
## Development
After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake spec` 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 tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).
## Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/alex0112/haversack.
## License
The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).