How to split a string into consecutive substrings of length at most 3 in all possible ways?

Question

I am trying to take a string, between length 1 and 10, and output all possible ways of breaking up the string into consecutive substrings that are of sizes 1, 2, or 3. For e

Answer 1

Here's another:

class String
  def splitup(prefix=nil)
    parts = []
    if size <= 3
      parts << [prefix,self].compact * ","
    end
    (1..([size,3].min)).each do |p|
      next if p >= size
      parts << slice(p..-1).splitup([prefix,slice(0,p)].compact * ",")
    end
    parts
  end

  def report
    flat = splitup.flatten.sort_by {|x| [-x.size,x]}
    puts
    puts "#{flat.size} permutations of #{self}"
    puts flat
  end
end

and then

>> "123456".report

24 permutations of 123456
1,2,3,4,5,6
1,2,3,4,56
1,2,3,45,6
1,2,34,5,6
1,23,4,5,6
12,3,4,5,6
1,2,3,456
1,2,34,56
1,2,345,6
1,23,4,56
1,23,45,6
1,234,5,6
12,3,4,56
12,3,45,6
12,34,5,6
123,4,5,6
1,23,456
1,234,56
12,3,456
12,34,56
12,345,6
123,4,56
123,45,6
123,456