From: Ryan Davis <ryand-ruby@...>
Date: 2007-05-19T00:21:50+09:00
Subject: Re: "Crystallizing" Objects


On May 18, 2007, at 01:55 , Robert Dober wrote:

> However the idea of an object state that allows to add information but
> forbids the loss/overwriting of information is just great.

and not the least bit new:

	http://www.amazon.com/Purely-Functional-Structures-Chris-Okasaki/dp/ 
0521663504