From: Pit Capitain <pit@...>
Date: 2004-10-02T00:54:01+09:00
Subject: Re: Can you rewrite this in a better way?

Bob Sidebotham schrieb:
> I would like to define a method that can be used to compactly define 
> some items of interest (here called "fields") for subclasses.
> 
> (...)
> 
> Here are two definitions for class A that support these semantics:
> 
> ---#1------------------------------------------------
> 
> (...)
> 
> ---#2------------------------------------------------
> 
> class A
>   def self.fields(*fields)
>     eval "def fields
>       [#{fields.collect{|f| ':' + f.to_s}.join(',')}]
>     end"
>   end
> end
> 
> -----------------------------------------------------
> 
> Is there a better way (more efficient, shorter and/or clearer) to do this?

#2 could be implemented as:

   class A
     def self.fields(*fields)
       define_method(:fields) { fields }
     end
   end

Here you don't need to build a textual version of the fields array.

Regards,
Pit