From: "Peña, Botp" <botp@...>
Date: 2007-06-05T10:32:02+09:00
Subject: Re: Reverse-range alternatives?

From: Kenneth McDonald [mailto:kenneth.m.mcdonald@sbcglobal.net] :
# Since a reverse range (eg. 4...1) is functionally almost the 
# same as an 
# empty range, is there an alternative in the standard library, where 
# .each would actually iterate over the elements from first to last, in 
# this case 4, 3, 2?

assumming we're all talking about range.

irb(main):014:0> x
=> 1..4
irb(main):015:0> x.class
=> Range
irb(main):016:0> x.last
=> 4
irb(main):017:0> x.first
=> 1
irb(main):018:0> x.last.downto x.first do |e|
irb(main):019:1*    p e
irb(main):020:1> end
4
3
2
1
=> 4


but i really hope something of a bidirectional range, ie, (4..1).to_a == [4,3,2,1] and (4..1)==(1..4).reverse, and then (4..1).each{|x| p x =>4,3,2,1

right now (4..1) is useless, but it does not _err..

kind regards -botp