From: Gavin Kistner <gavin@...>
Date: 2005-02-10T23:28:17+09:00
Subject: Re: Subclassing Immutable objects (Time)

On Feb 10, 2005, at 6:29 AM, Derek Wyatt wrote:
> I've been trying for a while to subclass Time, but i'm hitting some
> problems.  I tried simply overriding the methods in Time itself but
> after about 5 minutes i realized that i needed the old behaviour as
> well, so subclassing seems better.  I'm hitting the same problems with
> wrapping the object as well.

In my MutableTime class [1], I wrapped Time, rather than inheriting 
from it, and used method_missing to pass functions along to time.

Tiny snippets:

class MutableTime
	include Comparable

	def initialize( dateString_Seconds_Time_orYear = nil , *dateTimePieces 
)
		#...
		@t=Time.now
	end

	def method_missing(meth, *args, &block) # :nodoc:
		@t.send(meth, *args, &block)
	end

	def date=(n)
		@t+=(n-date)*86400;
	end

	def +(n)
		(d=self.dup).date+=n
		d;
	end
end


[1] http://phrogz.net/RubyLibs/rdoc/files/MutableTime_rb.html