From: arcadiorubiogarcia@...
Date: 2007-11-01T07:27:11+09:00
Subject: Re: Generation of initialize

Thanks. It was the "()" on super.

On 31 oct, 21:53, Joel VanderWerf <vj...@path.berkeley.edu> wrote:
> Trans wrote:
>
> > On Oct 31, 4:10 pm, arcadiorubiogar...@gmail.com wrote:
> >> Hi again,
>
> >> I'm trying to enhance the previous solution (shown again at the end).
> >> I'd like to call the initialize method of the superclass from the
> >> generated initialize. For the moment it's ok to call it without
> >> parameters. Simply placing super inside the method definition doesn't
> >> work. Can anyone explain me how to do it. Thanks in advance.
>
> > Why doesn't it work?
>
> >  def initialize_with(*params)
> >    define_method(:initialize) do |*args|
> >      if args.size != params.size then
> >        raise ArgumentError.new("wrong number of arguments"\
> >          " (#{args.size} for #{params.size})")
> >      end
> >      super() if defined?(super)
> >      params.zip(args) do |param, arg|
> >        instance_variable_set("@#{param}", arg)
> >      end
> >    end
> >    return params
> >  end
>
> > The "()" on super clears the auto-passing of parameters.
>
> It seems to work (if this is what you meant):
>
> module HasInitializeWith
>   def initialize_with(*params)
>     define_method(:initialize) do |*args|
>       if args.size != params.size then
>         raise ArgumentError.new("wrong number of arguments"\
>           " (#{args.size} for #{params.size})")
>       end
>       super() if defined?(super)
>       params.zip(args) do |param, arg|
>         instance_variable_set("@#{param}", arg)
>       end
>     end
>     return params
>   end
> end
>
> class A
>    extend HasInitializeWith
>    self.initialize_with :foo
> end
>
> p A.new(3)  # ==> #<A:0xb7c28cbc @foo=3>
>
> --
>        vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407