From: "Sean O'Dell" <sean@...[REMOVE_THE_SPAM]>
Date: 2003-09-13T05:38:46+09:00
Subject: Re: Should "new" methods do anything?

Philip Mak wrote:
> A programming style question:
> 
> Should "new" methods actually do anything, or should they only perform
> initialization?
> 
> For example, let's say I have a class called "Httpd" which runs an
> HTTP server. Should its interface be like this:
> 
>     server = Httpd.new(:listen_port => 80) # Initialize the server
>     server.run                             # Run it
> 
> Or like this?
> 
>     Httpd.new(:listen_port => 80) # Initialize and run the server
> 
> The latter way is more streamlined, but feels bad for some reason that
> I can't quite put into words right now.

I don't think it will cause any harm to your program, but to me it's 
non-intuitive as to what "new" does.  I don't think many people would 
expect that simply creating the server also launches it.

In those cases, I usually make a class method to combine the 
functionality, i.e.:

server = Httpd::launch_server(:listen_port => 80)

.... and keep the class like this:

class Httpd
   def initialize(listen_port)
     # init only
   end

   def run
     # launch the server
   end

   Httpd::launch_server(listen_port)
     server = Https.new(:listen_port = listen_port)
     server.run
     return server
   end
end


	Sean O'Dell