From: Ross Bamford <rossrt@...>
Date: 2006-05-06T19:06:32+09:00
Subject: Re: Record good idea?

On Sat, 2006-05-06 at 18:08 +0900, Frank Hirsch wrote:
> Hija!
> 
> I have made a little record class, because I needed it.
> 
> Maybe anyone finds this useful, or wants to beat me,
> because I have overtreaden some unwritten Ruby rule... :-)))
> 
> >---------------- cut here ----------------<
> 
> class Record
> =begin
> Little record class.
> (w) Frank Hirsch 2006
> =end
>   def method_missing(*a)
>     if (a.length!=2)
>       super
>     elsif (a[0].class!=Symbol)
>       super
>     else
>       name=a[0].id2name
>       value=a[1]
>       eval("@"+name+"value",binding)
>       eval("def "+name+"(v);@"+name+"v;end")
>       name.chop!
>       eval("def "+name+";@"+name+";end")
>     end
>   end
>   def initialize
>   end
> end
> 
> >---------------- and here ----------------<
> 
> Okay, what does anybody think?
> Useful or heresy or just an old hat?

I took the liberty of refactoring your code a bit, mainly to avoid
string eval and to ignore non-attribute single-arg methods:

class Record
  def method_missing(sym, *a)
    if (name = sym.to_s) =~ /[^=]=$/
      rdr, ivar, value = name.chop, "@#{rdr}", a.first

      (class << self; self; end).class_eval do
        define_method(sym) { |v| instance_variable_set("@#{rdr}",v) }
        define_method(rdr) { instance_variable_get("@#{rdr}") }
      end

      self.send(sym,value)
    else
      super
    end
  end
end

But please also check out:

	http://www.ruby-doc.org/stdlib/libdoc/ostruct/rdoc/
	http://www.ruby-doc.org/core/classes/Struct.html

-- 
Ross Bamford - rosco@roscopeco.REMOVE.co.uk