From: Jeff Cohen <cohen.jeff@...>
Date: 2006-03-09T10:34:42+09:00
Subject: Re: My Ruby talk @ work..

Stephen Waits wrote:
> I explained that each symbol has a unique ID, and that Ruby uses symbols
> to look stuff up within its own system.  I believe I had given them
> several ".send(:symbol)" examples at that point.

And it's much better than the "it's an immutable string" explanation, 
which I've found to be just a rats nest of problems.

Enums are another good analogy.  But in C++/C# enums are typed so you 
know the client gave you a valid value.  The only way I can see to 
enforce this in Ruby is to create a constant array of the valid symbols 
and then make sure what they passed me is in the array:

class HockeyGear

  BuyableGear = [ :stick, :helmet, :skates ]

  def self.buy_something(gear)
    if (!BuyableGear.include?(gear))
       return nil
    end

    # let them buy something...
  end

end

HockeyGear.buy_something(:soccer_ball) # returns nil


Somehow I feel this is pretty un-rubylike, to have to have that if 
statement in front of every method.  Any idea if there's a more 
ruby-like way to have enum-like behavior?

Thanks
Jeff

-- 
Posted via http://www.ruby-forum.com/.