From: Devin Mullins <twifkak@...>
Date: 2007-02-02T15:03:17+09:00
Subject: Re: halving a string

Naive solution:

class String
   def halve(max_len=nil)
     raise if max_len and size > max_len * 2 + 1
     space_indices = (0...size).find_all {|i| self[i] == ' '[0] }
     splitter = space_indices.sort_by {|i| (i - size/2).abs }.first
     if splitter.nil? ||
       (max_len && (splitter > max_len || size - splitter - 1 > max_len))
       [self[0...size/2], self[size/2..-1]]
     else
       [self[0...splitter], self[splitter+1..-1]]
     end
   end
end

if __FILE__ == $0
   require 'test/unit'

   class SplitterTest < Test::Unit::TestCase
     def test_stuff
       assert_equal ['the frog', 'is green'], 'the frog is green'.halve
       assert_equal ['ponchielli', 'wrote songs'],
                    'ponchielli wrote songs'.halve
       assert_raise(RuntimeError) { 'ab d'.halve 1 }
       assert_nothing_raised { 'a b'.halve 1 }
       assert_equal ['lizardman', 'lives'], 'lizardman lives'.halve
       assert_equal ['lizardm', 'an lives'], 'lizardman lives'.halve(8)
       assert_equal ['abcdef','ghijkl'], 'abcdefghijkl'.halve
     end
   end
end