Why doesn't backward for loop work in ruby? eg. for i in 10..1 [duplicate]

Question

Possible Duplicate:
Is there a reason that we cannot iterate on “reverse Range” in ruby?

This works like magic.

for i in 1..10
  ...
end

Isn't it only intuitive that this backward for loop should work as well?

for i in 10..1
  ...
end

If there is some syntactical reason why this shouldn't work, I feel like ruby has to be changed to allow it. It's just intuitive to write backward for loop that way.

Answer 1

try something like

10.downto(1) { |i| ... }

Answer 2

1..10 is of class Range, not directly linked with any loop constructs. And there are no numbers that are both bigger than 10 and smaller than 1, therefore the range 10..1 is empty.

PS I don't recall when was the last time I wrote a for loop in ruby. Maybe something from http://www.ruby-doc.org/core-1.9.2/Enumerable.html would serve you better?