From: "Dan Stevens (IAmAI)" <dan.stevens.iamai@...>
Date: 2007-02-06T04:54:11+09:00
Subject: Re: Enumerated Types

It seems to me that I should simply be able to use symbols as values
for my enumerated types, like for example:

class Color

  def initialize(color)
    @color = color
  end

  def to_hex
    case @color
      when :red: 0xFF0000
      when :green: 0x00FF00
      when :blue: 0x0000FF
      else @color
    end
  end

end

c = Color.new(:red)
puts c.to_hex.to_s(16)

Might there be any reason why I shouldn't do this, or am I quite fine
doing this?


On 03/02/07, Robert Klemme <shortcutter@googlemail.com> wrote:
> On 03.02.2007 19:52, Dan Stevens (IAmAI) wrote:
> > As part of a solution, I wish the value of an attribute to be one of a
> > finite set of values, in other words I believe I want an 'enumerated
> > type'. I've look at the 'Enumerable' and 'Enumerator' class and they
> > appear to me to be unrelated to what I wish to achieve (correct me if
> > I'm wrong).
> >
> > I could do the traditional method of named constants with integer
> > values but I can't help feeling that there must be a class or some
> > nice method of doing this. Any advice would be appreciated.
>
> I believe there are enum classes in the RAA.  If you do not want to use
> them, symbols come pretty close:
>
> class YourClass
>    YOUR_ENUM = [
>      :old,
>      :young,
>      :unknown,
>    ].freeze
> end
>
> HTH
>
> Kind regards
>
>         robert
>
>