From: Robert Klemme <shortcutter@...>
Date: 2010-11-13T04:50:20+09:00
Subject: Re: Ruby vs PHP for the web

On 11/12/2010 05:35 PM, Mike Stephens wrote:
> Robert Klemme wrote in post #960960:
>>
>> There seems to be some disagreement what exactly "strongly" and
>> "weakly" means here.
>
> To me it's pretty straightforward. An object of Class A cannot be
> treated as an object of Class B - the language system detects and
> prevents this. Ruby does not follow this approach. It uses duck typing
> which is the opposite.

So you are claiming that Ruby is weakly typed.  It is not.  Ruby does 
not allow an instance of A to be treated as an instance of B.  Duck 
typing really only means that Ruby does not have interfaces and uses 
dynamic typing.  In other words, all instances answering a particular 
set of methods can be used in a piece of code, e.g.

def append(a,b)
   a << b
end

append $stderr, "Last warning!"
append ARGV, "--help"
append [1,2,3], 4

See also Joel's example from C.  This is not possible in Ruby.

Kind regards

	robert