From: Yusuke ENDOH <mame@...>
Date: 2010-02-02T12:44:45+09:00
Subject: [ruby-core:28003] Re: [Bug #2495](Open) Matrix: Vector#each2 should 	check its argument

Hi,

2010/2/2 Marc-Andre Lafortune <redmine@ruby-lang.org>:
> Finally, I feel it would be superior to raise a TypeError instead of a NoMethodError in a case where duck typing fails, in a similar fashion to "$stdout = nil" which raises TypeError: $stdout must have write method, NilClass given


I really understand your intuition and even wrote the patch once,
but to achieve it, I guess that very many type checks will be needed,
not only in Vector#each2 but also in other libraries.  It may not be
realistic.
I think that `the fate of duck typing' includes such a error.

Now that I think about it, a type means "what methods its instance
responds to."  Thus, it may be strange to distinguish TypeError and
NoMethodError.

That's just my personal opinion, though.
Matz or Keiju, will you give us your opinion?

-- 
Yusuke ENDOH <mame@tsg.ne.jp>