Natural_deduction : UTF8_segmenter.utf_8

let utf_8_segments (boundary : Uuseg.boundary) (s : string) : string list =
        let flush_segment (buf : Buffer.t) (acc : string list) : string list =
                let segment : string = Buffer.contents buf in
                let _ : unit = Buffer.clear buf in
                if segment = "" then acc else segment :: acc
        in
        let rec add (buf : Buffer.t) (acc : string list) (segmenter : Uuseg.t) (v : [ `Await | `End | `Uchar of Uchar.t ]) : string list =
                match ((Uuseg.add segmenter v) : Uuseg.ret) with
                | `Uchar u ->
                        let _ : unit = Buffer.add_utf_8_uchar buf u in
                        add buf acc segmenter `Await
                | `Boundary -> add buf (flush_segment buf acc) segmenter `Await
                | `Await 
                | `End -> acc
        in
        let rec loop (buf : Buffer.t) (acc : string list) (s : string) (i : int) (max : int) (segmenter : Uuseg.t) : string list =
                if i > max then flush_segment buf (add buf acc segmenter `End) else
                let dec : Uchar.utf_decode = String.get_utf_8_uchar s i in
                let acc : string list = add buf acc segmenter (`Uchar (Uchar.utf_decode_uchar dec)) in
                loop buf acc s (i + Uchar.utf_decode_length dec) max segmenter
        in
        let buf : Buffer.t = Buffer.create 42 in
        let segmenter : Uuseg.t = Uuseg.create boundary in
        List.rev (loop buf [] s 0 (String.length s - 1) segmenter)