From: "David A. Black" <dblack@...>
Date: 2010-08-01T20:57:20+09:00
Subject: Re: what is the correct way to extend native methods?

Hi --

On Sun, 1 Aug 2010, Brian Candler wrote:

> Maurizio De Santis wrote:
>> why??
>
> What ruby are you using? With ruby 1.8.7 (2010-01-10 patchlevel 249)
> [x86_64-linux] and your posted code, I get the following output:
>
> ["a", "ab"]
> "b"
> ert.rb:17:in `[]': can't convert Regexp into Integer (TypeError)
>  from ert.rb:17
>
> If I change it to
>
>  alias_method :slice_without_regexp, :slice
>  alias_method :slice, :slice_with_regexp
>  alias_method :[], :slice_with_regexp
>
> then *that* gives a stack too deep error, but on the initial slice call.
>
> I'm afraid I don't know the solution though. I suspect slice is already
> an alias for [], or vice versa.

They are indeed the same method:

     rb_define_method(rb_cArray, "[]", rb_ary_aref, -1);
     rb_define_method(rb_cArray, "slice", rb_ary_aref, -1);


David

-- 
David A. Black, Senior Developer, Cyrus Innovation Inc.

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