From: gabriele renzi <surrender_it@...1.vip.ukl.yahoo.com>
Date: 2004-06-05T19:33:40+09:00
Subject: Re: How to ducktype a Hash?

il Sat, 5 Jun 2004 04:59:27 +0000 (UTC), Steven Grady From:
<grady@scam.XCF.Berkeley.EDU> ha scritto::

>>On Sat, 5 Jun 2004, Sean O'Dell wrote:
>> I need to detect when an object is a hash-like container for other objects,
>> one which responds to [] and which can index using any object as a value
>> (string, etc.).
>
>You have two requirements: that it respond to [], and that it can
>index any object.  I think you can check these both at run-time with:
>    def isHash(o)
>	begin o[Object.new] rescue return false end
>	return true
>    end
>
>Does this meet your needs?

you don't need the begin..end, a method block is an "exception
container" by itself:

def isHash(o)
  o[Object.new]
  true
 rescue
  false
end