From: Eero Saynatkari <ruby-ml@...>
Date: 2006-10-23T09:00:19+09:00
Subject: Re: Ruby-ize me (or at least my code)

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On 2006.10.23 07:51, Seth Eliot wrote:
> Hi all,
>=20
> I am new to Ruby but find it interesting.  To teach myself the language=
=20
> I wrote a simple linked list implementation.  It works just fine, but I=
=20
> suspect that my "Java is showing" and that the same logic can be written=
=20
> in a much more Ruby-ish fashion.

It is mostly an imperative style that is showing for some odd reason :)
Instead of critiquing, I will give you an alternative implementation to
munch upon.

> So I'd appreciate it if you can show me the Ruby way of implementing the=
=20
> following functionality.
>=20
> (The one thing I know is that I am not really taking advantage of OOP by=
=20
> making my methods in LinkedListSe.rb just static utility methods??? that'=
s=20
> fine for now)
> (also "next_1" is just my way of not colliding with the reserved keyword=
=20
> "next")

# I have not actually run this code, just typing out at work
class Node
  include Enumerable

  attr_accessor 'data', 'succ'

  # New node with the given data
  def new(data, succ =3D nil)
    @data, @succ =3D data.first, succ
  end

  # Chainable append from arbitrary data
  def <<(data)=20
    @succ =3D Node.new data
    @succ
  end

  # Insert a node at a given position
  def insert_at(pos, data)
    return Node.new(data, self) if pos =3D=3D 0
              =20
    @succ.insert_at((pos - 1), data)
    self
  end

  # Traversal
  def each(&block)
    yield @data
    @succ.each &block
  end

  # Stringimafy
  def to_s()
    map {|data| data.to_s}.join ' -> '
  end
end

list =3D Node.new('foo') << 'bar' << 'baz' << 'quux'


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