From: Yukihiro Matsumoto <matz@...>
Date: 2006-09-21T10:52:36+09:00
Subject: Re: [ANN] Ducktator - A Duck Type Validator

Hi,

In message "Re: [ANN] Ducktator - A Duck Type Validator"
    on Thu, 21 Sep 2006 08:59:45 +0900, Hal Fulton <hal9000@hypermetrics.com> writes:

|Austin is right. If you're checking types, that isn't duck typing.

Although I am not Dave Thomas, I consider it is a _variation_ of duck
typing, if the type describes behavior, not structure nor type name.
Signature validation is approximation of type-by-behavior.  As Austin
stated, some doesn't consider it duck typing, I agree.  But Keeping
strict definition of duck typing is not that important to justify
strong words in the list (and blogs).

For signature validation, we should note that respond_to? does not
work well for objects with method_missing.

							matz.