From: Robert Klemme <bob.news@...>
Date: 2004-11-15T23:43:23+09:00
Subject: Re: OpenStruct#update ?


"trans. (T. Onoma)" <transami@runbox.com> schrieb im Newsbeitrag
news:200411150844.12388.transami@runbox.com...
> On Monday 15 November 2004 07:38 am, Robert Klemme wrote:
> | "Florian Gross" <flgr@ccan.de> schrieb im Newsbeitrag
> | news:2vrj8eF2oj365U1@uni-berlin.de...
> |
> | > trans. (T. Onoma) wrote:
> | > > Sure. Okay first, basically what I was doing, given object o and
data
> |
> | in hash
> |
> | > > h:
> | > >
> | > >     h.each do |k,v|
> | > >       o.instance_variable_set("@#{k}", v)
> | > >       o.instance_eval <<-EOS
> | > >         def #{k}; @#{k}; end
> | > >         def #{k}=(x); @#{k}=x; end
> | > >       EOS
> | > >     end
> | >
> | > h.each do |k,v|
> | >    class << o; self; end.send(:attr_accessor, k)
> | >    o.k = v
> | > end
> |
> | Are you sure, this works?  IMHO this is more efficient:
>
> Actually the example is pulled inside out from the real method I use
which is
> a method of class Object (where it does work). So no the above probably
> doesn't work as give --but was just intended to give approx. notion of
what
> I'm doing.

I mean't Florian's code not yours.  Sorry if that hasn't become clear
'nough.

> | class << o; self; end.send(:attr_accessor, *h.keys)
> | h.each do |k,v|
> |    o.send("#{k}=", v)
> | end
> |
> | But it would be even better to check for existing methods in order to
not
> | overwrite existing methods:
> |
> | cl = class << o; self; end
> | im = cl.instance_methods
> | h.each do |k,v|
> |    cl.send(:attr_reader, k) unless im.include?(k.to_s)
> |    cl.send(:attr_writer, k) unless im.include?("#{k}=")
> |    o.send("#{k}=", v)
> | end
>
> I'm not sure I want that. Hmm... It's a sticky issue depending largely
on the
> particular use case. I think it makes sense for general use, so
yes --I'll
> add something like that, thanks. Should it raise an error instead?
>
> But in the context of an OpenStruct, no. OpenStruct focus is on data.

Full ACK.

Kind regards

    robert