From: Sean O'Dell <sean@...>
Date: 2004-06-06T02:24:12+09:00
Subject: Re: How to ducktype a Hash?

On Friday 04 June 2004 22:03, Steven@ruby-lang.org, Grady@ruby-lang.org, 
From@ruby-lang.org: wrote:
> >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

That's a little bit expensive.  I'm sure it works, but way too much overhead 
for just a type check.

	Sean O'Dell