Source file utils.ml

let points_to_lines points =
  (* The caller to this has already sorted the list, and so is sensitive to return order *)
  let rec last list =
    match list with
    | [] -> failwith "shouldn't get here"
    | [ x ] -> x
    | _ :: xs -> last xs
  in
  let res =
    match points with
    | [] | [ _ ] -> []
    | p1 :: p2 :: ptl ->
        let hd = p1 in
        let tl = last points in
        let rec point_list_to_lines p1 p2 pl acc =
          match pl with
          | [] -> (p1, p2) :: acc
          | np :: tl -> point_list_to_lines p2 np tl ((p1, p2) :: acc)
        in
        point_list_to_lines p1 p2 ptl [ (tl, hd) ]
  in
  res