(feature was initially added in #175 where there's some discussion about output)

Lgtm; fixing the trailing spaces and newline sounds good! I just noticed that cstruct doesn't use ocaml-hex from mirage, but the extra dependency probably isnt worth it

well, I'd welcome a single to/of_hex -- i.e. Cstruct using the hex library instead of containing the very same code once more... I thought we discussed this somewhere, but I'm unable to find the discussion :/

having said this, I'm ok with these changes - but would appreciate them to be applied to the hex library and that being used here :)

OK, I'll do the fixes here first and merge the implementations in a separate PR. At the moment, ocaml-hex has a different output format, so that will mean adding a new option over there.

@emillon great, thanks!

I removed the spaces and used a vbox instead of forcing a newline.

As for the trailing newline, after trying I don't think it's hexdump_pp's responsibility to add a break at the end.

For example, let's say we're trying to write some text and a hanging hexdump:

Some text 00 01 03....
          11 ....
          3f ....

At the moment there is no trailing newline. But forcing a break will insert spaces (indicated by ␣):

Some text 00 01 03....
          11 ....
          3f ....
␣␣␣␣␣␣␣␣␣␣

Which makes it impossible to output things like:

Some text 00 01 03....
          11 ....
          3f ....
Something else

So, we can merge this as this already fixes the trailing spaces, and try to think of a better solution once it's merged with hex :)

thanks!