From: Hal Fulton <hal9000@...>
Date: 2003-09-13T17:13:17+09:00
Subject: Re: Duck Typing

Meino Christian Cramer wrote:
> From: dblack@superlink.net
> Subject: Re: Duck Typing
> Date: Sat, 13 Sep 2003 10:29:52 +0900
> 
> Hi, first of all: I am very happy to have a programming language with
> such a communicative and friendly mailinglist!!! :)
> 
> 	 GREAT!
> 
> (Whether it will be  a good idea or not to mirror the posts into a newsgroup
> -- we will see. Previously I had made bad experiences, since my email
> postbox was overloaded with spam. Spammers do scan newsgroups for
> addresses... but this is quite another topic...) 
> 
> Back to the ducks !
> 
> 
>>Or even, more generally, left with the impression that there's an
>>on/off switch: if you say "is_a?" a lot, then you're not doing duck
>>typing, whereas if you say "respond_to?" a lot, then you are -- when
>>in fact it's really Ruby that's doing the duck typing, and you're
>>just deciding how to react to it.
> 
> 
>   If both works: is_a? and respond_to? : What is the advance of one
>   over the other beside the fact, that one has a cool name : "Duck
>   typing"? 
> 
>   Is one slower, less clean or ... ? I am just curious...

Don't misunderstand. David is saying that this is *some* people's
impression of what duck typing means.

Note the second part: "--when in fact it's really Ruby that's doing
the duck typing, and you're just deciding how to react to it."

It's not a coding style or technique; it's an attribute of the
language.

Hal