From: Logan Capaldo <logancapaldo@...>
Date: 2006-10-04T23:59:43+09:00
Subject: Re: Equvialent of Python slices?

On Wed, Oct 04, 2006 at 11:10:10PM +0900, Daniel Berger wrote:
> 
> James Edward Gray II wrote:
> > On Oct 4, 2006, at 8:19 AM, Peter Szinek wrote:
> >
> > > Hello,
> > >
> > > Sorry for the lame question again, but even after a lot of googling
> > > I still couldn't find the $subj., ie. something like:
> > >
> > > >>> "asdfghj"[2::2]
> > > 'dgj'
> > > (= every second letter, beginning from the 2nd index in the string)
> 
> Interesting, though I'm surprised Python has explicit syntax for what
> seems like a highly specific type of operation.  But, hey, cool.
> 
> > I'm not going to call this as pretty, of course, but:
> >
> >  >> test = "asdfghj"
> > => "asdfghj"
> >  >> test[2..-1].gsub(/(.)./, "\\1")
> > => "dgj"
> 
> Slightly OT here....
> 
> I'm trying to remember why test[2, -1] returns nil.  Positive numbers
> for the second integer work as expected:
> 
> test[2,1] => 'd'
> test[2,2] => 'df'
> test[2,100] => dfghj
> test[2,-1] => nil
I can see it logically, test[start position, length]. A negative one
length doesn't make much sense. test[2..-1] works though, since it's
start postion..(.)end position. Unfortunately you can't coun't backwards
with a negative length ( like if I want the last two characters I can't
say test[-1, -2]. )
> 
> /me considers a patch to string.c
> 
> Regards,
> 
> Dan
>