Clojure: Semi-Flattening a nested Sequence

Question

I have a list with embedded lists of vectors, which looks like:

(([1 2]) ([3 4] [5 6]) ([7 8]))

Which I know is not ideal to work with. I\'d lik

Answer 1

The code for flatten is fairly short:

(defn flatten
  [x]
  (filter (complement sequential?)
    (rest (tree-seq sequential? seq x))))

It uses tree-seq to walk through the data structure and return a sequence of the atoms. Since we want all the bottom-level sequences, we could modify it like this:

(defn almost-flatten
  [x]
  (filter #(and (sequential? %) (not-any? sequential? %))
    (rest (tree-seq #(and (sequential? %) (some sequential? %)) seq x))))

so we return all the sequences that don't contain sequences.