From: "Hal E. Fulton" <hal9000@...>
Date: 2001-09-08T00:47:47+09:00
Subject: [ruby-talk:20983] Re: destructor

----- Original Message -----
From: Nat Pryce <nat.pryce@b13media.com>
To: ruby-talk ML <ruby-talk@ruby-lang.org>
Sent: Friday, September 07, 2001 6:34 AM
Subject: [ruby-talk:20978] Re: destructor


> Ruby uses blocks to scope resource allocation and deallocation to scopes ,
> just like C++ does with constructors/destructors.  Look at the File::open
> method for an example.
>
> The basic idiom is for the class to define a method that takes a block,
> create an instance, pass it to the block, and then destroy the instance
with
> an ensure statement.
>
> Here's some pseudocode illustrating this idiom in the abstract...
>
> class Resource
>     def Resource.use( param )
>         resource = Resource.new( param )
>         try
>             return yield( resource )
>         ensure
>             resource.close
>         end
>     end
> end

That's an excellent way of explaining it.

Hal