class Dry::Types::Sum

def call_safe(input, &block)
  left.call_safe(input) { right.call_safe(input, &block) }
end

def call_unsafe(input)
  left.call_safe(input) { right.call_unsafe(input) }
end

def constrained(options)
  if optional?
    right.constrained(options).optional
  else
    super
  end
end

def constrained?
  false
end

def default?
  false
end

def failure(input, _error = nil)
  if !left.valid?(input)
    left.failure(input, left.try(input).error)
  else
    right.failure(input, right.try(input).error)
  end
end

def initialize(left, right, **options)
  super
  @left, @right = left, right
  freeze
end

def meta(data = nil)
  if data.nil?
    optional? ? right.meta : super
  elsif optional?
    self.class.new(left, right.meta(data), **options)
  else
    super
  end
end

def name
  [left, right].map(&:name).join(' | ')
end

def optional?
  primitive?(nil)
end

def primitive?(value)
  left.primitive?(value) || right.primitive?(value)
end

def success(input)
  if left.valid?(input)
    left.success(input)
  elsif right.valid?(input)
    right.success(input)
  else
    raise ArgumentError, "Invalid success value '#{input}' for #{inspect}"
  end
end

def to_ast(meta: true)
  [:sum, [left.to_ast(meta: meta), right.to_ast(meta: meta), meta ? self.meta : EMPTY_HASH]]
end

def to_proc
  proc { |value| self.(value) }
end

def try(input)
  left.try(input) do
    right.try(input) do |failure|
      if block_given?
        yield(failure)
      else
        failure
      end
    end
  end
end