From: "Berger, Daniel" <Daniel.Berger@...>
Date: 2006-02-10T04:51:58+09:00
Subject: Re: How to improve this kind of API?

> -----Original Message-----
> From: Lyle Johnson [mailto:lyle.johnson@gmail.com] 
> Sent: Thursday, February 09, 2006 12:43 PM
> To: ruby-talk ML
> Subject: How to improve this kind of API?
> 
> 
> I'm looking to make an API change for some methods in FXRuby 
> and would appreciate some suggestions about how to improve 
> them. The pattern shows up in several places in the code, but 
> it always boils down to some widget attribute that can have a 
> combination of bit-flags. For example, the 4-way splitter 
> window can be configured to expand only its top-left pane:
> 
> splitter1.expanded = TOP_LEFT
> 
> or to expand both the top left and top right panes:
> 
> splitter2.expanded = TOP_LEFT | TOP_RIGHT
> 
> And to check whether, say, the BOTTOM_LEFT pane is expanded:
> 
> (splitter3.expanded & BOTTOM_LEFT) != 0
> 
> Now, what I'm thinking of doing is replacing the symbolic 
> constants with Ruby symbols, and doing something like this instead:
> 
> splitter1.expand(:top_left)
> splitter2.expand(:top_left, :top_right)
> 
> and then having checks like:
> 
> splitter3.expanded? :bottom_left
> 
> I think that in order to "turn off" one of those bits, I'm 
> probably also going to need to add something like:
> 
> splitter4.unexpand(:bottom_right)
> 
> Now, the question is, is there some existing pattern in Ruby 
> that this reminds you of? In other words, what is the Ruby 
> Way to handle this kind of setting?
> 
> Thanks in advance for your suggestions!
> 
> Lyle

FWIW, I think what you've posted here looks good, so long as I could use
strings as well, e.g. splitter.expand("top_left").

Regards,

Dan