From: Mike Iles <mikei@...>
Date: 2004-04-06T04:19:47+09:00
Subject: Re: deciding between ruby and python


From: Charles Comstock [mailto:cc1@cec.wustl.edu] 
> Yea but that doesn't give you the guarenteed cleanup that the
> yield syntax allows.  In c++ this would be accomplished by using
> a guarded object that would destruct when the scope was exited,
> there is no comparable operation in java, without explictely 
> declaring a wrapping try / catch / finally.  In C# V2.0 it is
> possible because of the existance of yield.  It is not possible
> in C# 1.0.  

This can also be achieved in C# 1.0 with the 'using' statement:

class ExternalResource : System.IDisposable {
	public ExternalResource() {
		... acquire the resource ...
	}
	public void Dispose() {
		... release the resource ...
	}
}

then code to use it looks like,

	...
	using ( resource = new ExternalResource() ) {
		... use the resource ...
	}
	...

If the object will be used without a 'using' statement then a bit more
logic is required to add a finalizer and co-ordinate between the Dispose
method and the finalizer.

Mike.