crash.re

 let insert = site => {
    let (leftSide, rightSide) = sites^ |> List.partition(s => s.left <= site.left);
    let (overlap, rest) = rightSide |> List.partition(s => s.left <= site.right);

    let rightSide = switch(overlap) {
    | [] => [site, ...rightSide]
    | _ => let closest = overlap->List.rev->List.hd; [site->connectRight(closest), ...rest]
    }

    let site = rightSide->List.hd;

    let leftSide = switch (leftSide->List.rev) {
    | [s, ...rest] when s.right >= site.left => [s->connectRight(site), ...rest]->List.rev
    | _ => leftSide->List.append([site])
    };

    sites := switch (rightSide->List.tl) {
    | tail => leftSide->List.append(tail)
    | exception Failure(_) => leftSide
    };
  };