Bug: Spaces added to preformatted code style docstring elements

[jberdine]

Describe the bug
Formatting code such as:

type sp =
  | Cut  (** {[@,]} *)

adds spaces within the preformatted code element, producing

type sp =
  | Cut  (** {[ @, ]} *)

How to Reproduce
Change the Cut docstring in Fmt.mli as above and make test.

[Julow]

That's the formatting we expect, to separate the heavier syntax {[ from the bigger piece of code. Perhaps the source can be changed to use [ ... ] instead, which is expected to contain a small bit of code and isn't formatted by ocamlformat.

Note that this code block will appear heavy in Odoc's output.

[gpetiot]

I don't know what would look better in odoc's output, I'm neutral regarding using wrap "[@;<1 2>" "@ ]" or wrap "[@;<0 2>" "@,]", but I admit having spaces added can be surprising

[jberdine]

Maybe it is just me, but my interpretation of "preformatted" in the spec makes me think that adding spaces is quite surprising.

[Julow]

Odoc doesn't follow ocamldoc in a lot of cases. Odoc is not sensitive to whitespaces around {[ and ]} and to the indentation of the whole block. It's reasonable to add spaces and newlines here and to indent the whole block. (we do all this)

[Julow]

I think this can be closed since the parsing and formatting of code spans changed ocaml/odoc#1085