From: Siemen Baader <siemenbaader@...>
Date: 2009-11-16T21:11:24+09:00
Subject: Re: Traversing the contents of a proc (for a DSL)

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On Mon, Nov 16, 2009 at 1:50 AM, Ryan Davis <ryand-ruby@zenspider.com>wrote:

>
> On Nov 15, 2009, at 12:01 , Siemen Baader wrote:
>
> > Thanks! The two introspection libs look really interesting.
> >
> > I know that there are plenty of templating tools available. But I'm just
> > playing around with DSLs and chose HTML because it is such a well-known
> > domain with familiar problems.
>
> The point wasn't (necessarily) to use them, but to study them. You simply
> don't need to traverse the proc to do what you want to do.
>

Yes, I will definitely have a look at them!



> class PseudoLisp
>   def self.convert &b
>     self.new.instance_eval(&b)
>   end
>
>   def method_missing(msg, *args, &b)
>     if args.empty? then
>       puts "(#{msg})"
>     else
>       puts "(#{msg} #{args.join(' ')})"
>     end
>   end
> end
>
> PseudoLisp.convert do
>   happy
>   "string created"
>   sad 42
> end

#=> (happy)
#=> (sad 42)

Thanks a lot for the example!

There is one caveat with it - I also need to catch the creation of strings.
Of course I can work around this by using a method call to construct text
(eg text "text body"). Hm.. maybe I can also hook into something with
ObjectSpace or String.new; I have to check that out when I come back to my
dev machine...

-- Siemen

>
PS. It looks like I'm always double posting for some reason, my apologies,
List.. I'll hope it is fixed now..

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