code: function flatten(seq) { var pending, result, item
          result  = []
          pending = slice(seq)
          while (item || pending.length) {
              if (!pending.length) break
  
              item = pending.shift()
              if (arrayp(item))
                  pending.unshift.apply(pending, item)
              else if (sequencep(item))
                  pending.unshift.apply(pending, to_array(item))
              else
                  result.push(item) }
  
          return result
      }
docs: /// Function flatten /////////////////////////////////////////////////////  (seq:Sequence) ↦ Array  Returns an one dimensional array, by inlineing all sublists.