On Sep 12, 2005, at 8:24 PM, Daniel Sheppard wrote: > <<quiz_46_ndiff.rb>> This quiz made me delve into the darkened > alleyways of undocumented standard libraries (well, bigdecimal). > Luckily > the whole thing worked exactly as guessed - probably why nobody has > bothered documenting it yet. Nice solution. Just one small comment: ... SyncEnumerator.new(file1, file2).each do |line1, line2| line1, line2 = NumberLine.new(line1), NumberLine.new(line2) SyncEnumerator.new(line1, line2).collect { |num1, num2| distances << (num1 - num2).abs } end ... I'm pretty sure you meant each() instead of collect() for that second SyncEnumerator. I just wanted to point that out, since I changed it in the quiz summary. James Edward Gray II