arrays - In Ruby I need to split a sentence into sub-sentences -

given string:

"see spot run" 

i need return array with:

[ "see", "spot", "run", "see spot", "spot run", "see spot run" ] 

so far have:

term = "the cat sat on mat" #=> "the cat sat on mat"   arr = term.split(" ") #=> ["the", "cat", "sat", "on", "the", "mat"]   arr.length.times.map { |i| (arr.length - i).times.map { |j| arr[j..j+i].join(" ") } }.flatten(1) #=> ["the", "cat", "sat", "on", "the", "mat", "the cat", "cat sat", "sat on", "on the", "the mat", "the cat sat", "cat sat on", "sat on the", "on mat", "the cat sat on", "cat sat on the", "sat on mat", "the cat sat on the", "cat sat on mat", "the cat sat on mat"]  

this going happen lot of times, can think of way make more efficient?

i'd use each_cons in loop: (although it's not faster)

arr = %w[the cat sat on mat] (1..arr.size).flat_map { |i| arr.each_cons(i).map { |words| words.join(' ') } } #=> ["the", "cat", "sat", "on", "the", "mat", #    "the cat", "cat sat", "sat on", "on the", "the mat", #    "the cat sat", "cat sat on", "sat on the", "on mat", #    "the cat sat on", "cat sat on the", "sat on mat", #    "the cat sat on the", "cat sat on mat", #    "the cat sat on mat"]