From: Christoph Rippel <crippel@...>
Date: 2001-01-08T08:52:24+09:00
Subject: [ruby-talk:8799] Re: Backward Range implementation

> -----Original Message-----
> From: David Alan Black [mailto:dblack@candle.superlink.net]
> Sent: Sunday, January 07, 2001 02:00 PM
> To: ruby-talk ML
> Subject: [ruby-talk:8788] Re: Backward Range implementation
> 
> 
> Hello --
> 
> On Sun, 7 Jan 2001, Kevin Smith wrote:
> 
> > 
> > Here's what I came up with that seems to work. I 
> > didn't exhaustively test all the methods of 
> > Range, but I think I probably hit the ones that 
> > weren't working. Oh, I don't expect backward 
> > ranges to support exclusive mode (it seems 
> > unbalanced), so I didn't test that.
> > 
> > Gotta love this language
> > 
> > Kevin
...
> Further thoughts/hacks/enhancements/whatever?
> 
> 
> David
There is probably some code out there which relies on
the semantics that ``(0..-1).each do |i| whatever(i) end''
does nothing.

It seem more prudent to introduce a separate ``each_down''
iterator defined whenever a method ``#pred'' is provided?

On the other hand ``(7..0).each do |i| whatever(i) end''
looks certainly much nicer. 

Christoph