From: Dave Thomas <Dave@...>
Date: 2001-07-03T01:05:24+09:00
Subject: [ruby-talk:17157] Re: RCR: Exception methods (was: Re:  Re: keeping an Exception object alive)

David Alan Black <dblack@candle.superlink.net> writes:

> With regard to the second point: it's that I think it should be a
> private method, but that I wonder whether it should be/needs to be a
> Ruby method at all.  It seems more like part of the implementation
> internals (testing for validity of arguments to #raise).
> 
> By way of comparison: every time there's:
> 
>    if (TYPE(arg) == T_ARRAY) {...}
> 
> there could be, instead, something like:
> 
>    ID array = rb_intern("array");
>    /* ... */
>    if (rb_respond_to(arg, array)) {...}
> 
> along with an #array method to which some objects would respond and
> others wouldn't.  That would feel, to me, like a blurring of
> implementation internals (testing for type) and Ruby itself... which
> is what I'm wondering about #exception.

To be fair, just about every time the interpreter now checks for a
String, it checks to see if the receiver supports #to_str (via
str_to_str). When it's done, the prior check for T_STRING is simply an
optimization. So it looks like Ruby is moving towards typing by
interface internally.


Dave