Parenthesis Permutation: In 7 lines of Python

Here's a 1 liner port in ruby :<p>(l = -&#62;(n,s=',o=0,c=0){ puts s and return if s.length == n || l.call(n,s+')',o,c+1) || o&#60;n/2 &#38;&#38; l.call(n,s+'(',o+1,c) if o&#62;=c }).call(6)

This is a very cool tool, @spicavigo! I look forward to using it in recruiting.