From: Yukihiro Matsumoto <matz@...>
Date: 2010-03-02T17:29:46+09:00
Subject: [ruby-core:28401] Re: [Bug #2495] Matrix: Vector#each2 should check its argument

Hi,

In message "Re: [ruby-core:28399] [Bug #2495] Matrix: Vector#each2 should check its argument"
    on Tue, 2 Mar 2010 16:52:31 +0900, Marc-Andre Lafortune <redmine@ruby-lang.org> writes:

|On Mon, Feb 1, 2010 at 10:44 PM, Yusuke ENDOH <mame@tsg.ne.jp> wrote:
|> Matz or Keiju, will you give us your opinion?
|
|Ist Keiju is even registered on the ruby-core mailing list?

|I'd like to point out an alternate implementation can use #each instead of #[], and at least avoid the non-sensical results on integers. Example:

Accepted, but I prefer each_with_index though.

|I'm all for duck typing, as long as we give an idea of what type of "quacking" we're expecting. I would still suggest adding at the beginning of the method:
|
|unless v.respond_to?(:size) && v.respond_to?(:each)
|  raise TypeError, "Argument must respond to :size and :each"
|end

If we change the policy and decide to add respond_to? check to
methods, we add infinite number of checks everywhere (exaggerated of
course).  I am not in a mood to make such big change during 1.9.2
period.

							matz.