From: botp <botpena@...>
Date: 2011-10-17T16:31:56+09:00
Subject: Re: writing a poem backwards or in reverse order

On Mon, Oct 17, 2011 at 1:02 PM, teresa nuagen
<s-unguyen2@huskers.unl.edu> wrote:
> alright, so lets say this is an example:
>
> While moon sets
> atop the trees,
> leaves cling to rain.
>
> and I have to transform it into this:
> rain. to cling leaves
> trees, the atop
> sets moon While


s=<<-HERE
While moon sets
atop the trees,
leaves cling to rain.
HERE
#=> "While moon sets\natop the trees,\nleaves cling to rain.\n"

# let's split the string by newlines "\n"
# the splitted components will be stored in an array
a1=s.split("\n")
#=> ["While moon sets", "atop the trees,", "leaves cling to rain."]

# now, we arrange the array in reverse order
# note, you can just use the same var a1, but i'd prefer we
# use another var a2 so you can back track thru the vars
a2=a1.reverse
#=> ["leaves cling to rain.", "atop the trees,", "While moon sets"]

# stop. let's see where we are.
puts a2
leaves cling to rain.
atop the trees,
While moon sets
#=> nil

# good, we just need to arrange / reverse the words in the line
# again, we just split the line by spaces where we get an array,
# the call the reverse method for the array
a3=a2.split.reverse
NoMethodError: undefined method `split' for ["leaves cling to rain.",
"atop the trees,", "While moon sets"]:Array
	from (irb):22
	from /usr/local/bin/irb:12:in `<main>'

# oops :)

a3=a2.map{|x| x.split.reverse}
#=> [["rain.", "to", "cling", "leaves"], ["trees,", "the", "atop"],
["sets", "moon", "While"]]

# ok. i think we're near. we just need to join the words back
a4=a3.map{|x| x.join(" ")}
#=> ["rain. to cling leaves", "trees, the atop", "sets moon While"]

# now, let's see
puts a4
rain. to cling leaves
trees, the atop
sets moon While
#=> nil

# is that ok?