From: "Ara.T.Howard" <ahoward@...>
Date: 2004-05-25T09:53:45+09:00
Subject: Re: How to pp-enable a class?

On Tue, 25 May 2004, Hal Fulton wrote:

> Gavin Sinclair wrote:
> >>Are there good docs or even a tutorial on how to enable a class
> >>to be prettyprinted with pp?
> > 
> >>It looks like the sort of thing I could figure out in 5 or 6 hours
> >>of experimentation. I'd rather not spend those if I can help it.
> > 
> > I've never expended any effort "preparing" a class for pp'ing.  I just
> > pp it and am happy with the result.
> > 
> > Objects are just a recursive collection of objects and core types.
> > Core types have their pp defined, and objects are just structure.  So
> > it should all Just Work.
> 
> True in general.
> 
> But I have a case (hence my question) where it doesn't "just work"
> and I'm not sure why.
> 
> I can't reproduce it simply yet, or I'd show you.
> 
> 
> Hal

the other case where it does not work is in cases where you might want to use
#inspect, but do not because your object is not that pretty.  here is an
example and my work around:

  ~ > cat a.rb
  require 'pp'
  require 'logger'

  class Object
    def pretty port = ''
      PP::pp(self, port).strip
    end
  end

  class Config < Hash; end


  logger = Logger.new STDOUT
  conf = Config[ 'key' => 'value' ]

  logger.debug{ "conf <#{ conf.pretty }>" }


  ~ > ruby a.rb
  D, [2004-05-24T17:42:13.811603 #23616] DEBUG -- : conf <{"key"=>"value"}>

IMHO if you require 'pp' Object#pretty should be defined automatically.

cheers.

-a
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