From: Stefan Salewski <mail@...>
Date: 2011-02-24T21:53:03+09:00
Subject: Re: a, b = Array.new(2).map!{|x| data.dup}

On Thu, 2011-02-24 at 11:10 +0530, Anurag Priyam wrote:
> > ok, try also something like,
> >
> >  a,b,c,d,e =[x.dup]*5
> 
> That will cause a, b, c, d, e to point to the same objects, which
> might result in an unexpected side effect.
> 

Indeed, that was not what I wanted, I need 5 independent instances!


Brian Candler wrote:
>Stefan Salewski wrote in post #983443:
>> The code is related to handling configuration files, I have a basic
>> configuration set, a hash called @output. And variants for on screen,
>> pdf, png export.
>
>In that case, I'd say you'd be better off avoiding all the separate 
>instance variables for each variant, and make it data-driven. Then you 
>can interate over the variants, which will naturally avoid the repeated 
>code.
>
>FORMATS = [:scr, :png, :pdf, :svg, :ps]
>...
>@configs = {}
>FORMATS.each { |k| @configs[k] = @output.dup }
>
>Now you have @configs[:scr], @configs[:png] etc, all pointing to 
>separate copies of @output. And if you want to add another format in 
>future, it's a trivial change.
>
>(Aside: please do not post variants of this code using 'inject', because 
>it's stupid here. You know who you are. Thank you.)
>
>Regards,
>
>Brian.

I see the point, thanks.

Best regards,

Stefan Salewski