From: Michal Suchanek <hramrach@...>
Date: 2007-12-31T01:35:30+09:00
Subject: Re: RCR allow indexing last n items

On 30/12/2007, David A. Black <dblack@rubypal.com> wrote:
> Hi --
>
> On Sun, 30 Dec 2007, Michal Suchanek wrote:
>
> > Hello
> >
> > As  discussed in thread starting with ruby-talk # 284001 there is an
> > inconsistency in handling positive and negative range indexes to
> > arrays and strings.
> >
> > Currently the requirement is that the first number in the range does
> > fall into the string.
> >
> > This allows "asd'[0...10] to return the first (at most) 10 characters
> > of the string.
> >
> > However, the same cannot be done on the end:
> >
> > "asd"[-10..-1] returns nil even though this could mean the last (at
> > most) 10 characters as direct opposite of the above. However, the
> > first number (-10) yields an index length-10 = -7 which is outside of
> > the string.
> >
> > To make it possible to index the end of the string as easily as the
> > beginning the rules for indexing should be changed slightly.
>
> I'd rather not have the index magically converted. I don't think I can
> come up with an airtight technical reason. It just seems a bit
> over-engineered; I'd prefer for -10 to mean -10 from the right.

I want -10 to mean 10 from the right as it does now. I just want the
bounds checking to be the same  when counting from the right as it is
when counting from the left.

>
> > I would submit this to rcrchive but for some reason I cannot sign up for it.
>
> I just submitted your confirmation string, and it registered you. Did
> you never get the confirmation email?
>
>
> David
>
Yes, never got it. It happens for me with some email registrations.

Thanks

Michal