How to avoid line splitting in Format.printf?

Can someone please help me to get rid of the automatic line splitting due to Format.printf for the following piece of code. Using set_margin only seems to work up to a certain limit but doesn’t help for very very long lines.

let () = Map.iteri file_types ~f:(fun ~key:name ~data ->
    Format.printf "%s %s %a@." filename name Pprintast.core_type data

The full code is here:

I’ve tried to use Printf.printf, but the interface is not compatible:

Error: This expression has type Format.formatter -> core_type -> unit
       but an expression was expected of type out_channel -> 'a -> unit
       Type Format.formatter is not compatible with type out_channel

What is the issue exactly? Did you have an example of unintended line break? Did you remember to set max_indent to margin - 10 after increasing the margin?

Thanks @octachron! I didn’t know about set_max_indent, that solved the problem.