From: matz@... (Yukihiro Matsumoto)
Date: 2000-09-07T12:00:00+09:00
Subject: [ruby-talk:4813] Re: Some questions

Hi,

In message "[ruby-talk:4809] Some questions"
    on 00/09/07, Friedrich Dominicus <frido@q-software-solutions.com> writes:

|- is there a reason why there isn't a each_index in String?

Because String is not a indexed container.  You can use
each_with_index instead.

|- does Ruby do not provide some sort of List (I know Array are quite
|good enough, just wondering)

You mean linked list?  No, but it's easy to define your own list class.
Here's the lisp style simple example.

  class Cons
    def initialize(car,cdr=nil)
      @car = car
      @cdr = cdr
    end
    attr_accessor :car, :cdr
    def to_s
      if @cdr == nil
	"(#{@car})"
      else
	"(#{@car} #{@cdr})"
      end
    end
    alias inspect to_s
    def Cons::list(*args)
      if args.size == 0
        nil
      else
        Cons::new(args.shift, Cons::list(*args))
      end
    end
  end
  p Cons::list
  p Cons::list(1,2,3,4)

							matz.