Module: Data::Option

Defined in:
lib/data/option.rb,
lib/data/option/none.rb,
lib/data/option/some.rb,
lib/data/option/version.rb,
lib/data/option/refinement.rb

Defined Under Namespace

Modules: Refinement Classes: None

Constant Summary collapse

Some = 
Data.define(:value) do
  include Comparable

  def <=>(other)
    return 1 if other.is_a?(None)

    value <=> other.value
  end

  alias unwrap value
  alias unwrap_or_else value

  def unwrap_or(_default) = value
  def expect(_message) = value

  def and(other) = other.is_a?(Some) ? other : None[]
  def and_then = yield value
  def or(_other) = self
  def or_else = self
  def xor(other) = other.is_a?(Some) ? None[] : self

  def each
    yield value

    self
  end

  def map = Some[yield value]
  def filter = yield(value) ? self : None[]
  def flat_map(&) = map(&).flatten

  def flatten
    case value
    in None | Some
      value
    else
      self
    end
  end

  def map_or(_default) = yield value
  alias map_or_else map_or

  def some? = true
  def none? = false

  def some_and? = yield value
  alias none_or? some_and?

  def inspect = "Some[#{value.inspect}]"
  alias to_s inspect

  def pretty_print(pp)
    pp.group(1, 'Some[', ']') do
      pp.breakable('')
      case value
      in Some | None
        value.pretty_print(pp)
      else
        pp.pp(value)
      end
    end
  end
end
VERSION = 
'0.1.0'

Class Method Summary collapse

Class Method Details

.from(value) ⇒ Object

Creates an Option from a value. Returns ‘None` if the value is `nil`, otherwise returns `Some`.



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# File 'lib/data/option.rb', line 13

def self.from(value)
  value.nil? ? None[] : Some[value]
end