README.md

Bitmask

Bitmask represents a set of boolean values as an Integer.

This bitmask gem was extracted from amiel/has_bitmask_attributes

Installation

Add this line to your application's Gemfile:

gem 'bitmask'

And then execute:

$ bundle

Or install it yourself as:

$ gem install bitmask

Usage

Examples:

  masks = {
            :cat  => 0b0001,
            :dog  => 0b0010,
            :fish => 0b0100,
          }

  bitmask = Bitmask.new(masks, {:cat => true})
  bitmask.to_i            # => 1
  bitmask.get :cat        # => true
  bitmask.get :dog        # => false
  bitmask.set :dog, true
  bitmask.get :dog        # => true
  bitmask.to_i            # => 3
  bitmask.to_h            # => { :cat => true, :dog => true, :fish => false }

  bitmask = Bitmask.new(masks, 0b101)
  bitmask.to_h            # => { :cat => true, :dog => false, :fish => true }
  bitmask.to_i            # => 5
  bitmask.to_i.to_s(2)    # => "101"

  Bitmask.new(masks, 5) == Bitmask.new(masks, { :cat => true, :dog => false, :fish => true }) # => true

  # Least Significant Bit - LSB
  bitmask = Bitmask.new(masks, {:cat => true, :fish => true})
  bitmask.lsb # => 1
  bitmask.lsb.to_s(2) # => "1"
  Bitmask.new(masks, bitmask.lsb).to_a # => [:cat]

  # Most Significant Bit - MSB
  bitmask = Bitmask.new(masks, 0b101)
  bitmask.msb # => 4
  bitmask.msb.to_s(2) # => "100"
  Bitmask.new(masks, bitmask.msb).to_a # => [:fish]

Chaining

  masks = {
            :cat  => 0b0001,
            :dog  => 0b0010,
            :fish => 0b0100,
          }
  bitmask = Bitmask.new(masks, {:cat => true})
  bitmask.to_i.to_s(2)    # => "1"
  bitmask.set(:dog, true).set(:cat, false).set(:fish, true)
  bitmask.to_i.to_s(2)    # => "110"

Contributing

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