From: Robert Klemme <shortcutter@...>
Date: 2008-02-16T21:24:54+09:00
Subject: Re: Alter String base class to perform new (private methods) before    returning itself when called by print statements

On 16.02.2008 07:26, Steven G. Harms wrote:
> class String
>   def summon
>     puts "You summon: " + self
>   end
>   def summon2
>     puts "You summon: " + self.gsub('x','y')
>   end
>   def to_s
>     return "Atreyu"
>   end
> end
> 
> "Artax".summon
> "Artax".summon2
> 
> puts "Artax".to_s # reference 1
> puts "Artax"        # reference 2
> 
> This produces...
> 
> You summon: Artax
> You summon: Artay
> Atreyu
> Artax
> 
> Now the "summon" methods indicate to me that by referencing self in
> methods added to the String class, you can alter the string from
> within itself.

Actually your summon methods do not alter self.

>  The question is, how can I get `puts "Artax" ` to
> produce the same results as `puts "Artax"`.

??? It's the same statement so I would expect the same output (module 
changes of the instance in between invocations).

>  They are both Strings
> and, as far as I understand it, to_s is what is used to get a String's
> display value.

It's generally not a good idea to mess with such basic classes like 
String in this way (i.e. make to_s return something else than self). 
Since your example does not contain context it's difficult to come up 
with appropriate suggestions.  What are you *really* trying to achieve?

> Question #1:  Is there a way to references 1 and 2, supra, to do the
> same thing?

Not sure what you mean here.  Can you explain?

> Question #2:  I thought perhaps I could do the magic on the assignment
> operation.  I'm not having too much luck with that, as yet.

You cannot change the semantics of assignment.  You can however define 
methods that look like assignment, i.e. def foo=(x)...end.  I doubt 
though that this is helpful for you in this context.

> If this is the best solution, could the responding individual please
> be so gracious as to provide example code of how to override
> assignment?  I'm muddling about with my re-defined initialize
> expecting an optional argument, but I've not figured out how to access
> it properly.

Again, what problem are you trying to solve?

Kind regards

	robert