From: Daniel Berger <djberg96@...>
Date: 2007-08-10T02:55:23+09:00
Subject: Re: Bug or bad documentation for Array.insert()



On Aug 9, 10:35 am, Markus Echterhoff <T...@edu.uni-klu.ac.at> wrote:
> I just came across ruby and noticed a difference between the behavior of
> Array.insert() and its documentation.
>
> Method:http://www.ruby-doc.org/core/classes/Array.src/M002195.html
>
> From the RDoc it seems that two arguments are mandatory, yet Array.insert()
> only raises an error if there is no argument passed at all.
>
> Code snippet from Array.insert():
>
>     if (argc == 1) return ary;
>     if (argc < 1) {
>         rb_raise(rb_eArgError, "wrong number of arguments (at least 1)");
>     }
>
> From my semantic understanding of an "insert" Method it should raise an error
> if called with less than two arguments, for silently returning the array can
> be irritating for beginners (Took me some time to figure it out).

Nope, the docs show that the second argument is optional. As it stands
now there are a few methods like this scattered throughout Ruby where
you can end up with what amounts to a no-op in certain situations,
e.g. File.join with no arguments.

Not that I necessarily agree with the current semantics, but it is
documented properly. It does require that you understand "obj..." to
mean "0 or more".

Regards,

Dan