Recognize metadata labels in mli files

[Leonidas-from-XIV]

This is a revival of #339 with a bit of rebasing and a tiny bit more polish.

[Leonidas-from-XIV]

odoc-parser.1.0.0 is out, but unfortunately it conflicts with ocamlformat.0.19.0, so it forces a formatter downgrade which then has issues formatting our code.

[Julow]

OCamlformat 0.20.1 has been released today and has compatibility with odoc-parser 1.0.0.

[Julow]

The tests need to be promoted:

diff --git a/test/bin/mdx-test/expect/simple-mli/test-case.mli b/test/bin/mdx-test/expect/simple-mli/test-case.mli
index 254d76d..78c970e 100644
--- a/test/bin/mdx-test/expect/simple-mli/test-case.mli
+++ b/test/bin/mdx-test/expect/simple-mli/test-case.mli
@@ -47,5 +47,5 @@ val foo : string
 (** {@ocaml[1 + 1 = 3]} *)
 val bar : string
 
-(** {@ocaml skip [1 + 1 = 3]} *)
+(** {@ocaml skip[1 + 1 = 3]} *)
 val baz : string
diff --git a/test/lib/test_mli_parser.ml b/test/lib/test_mli_parser.ml
index 89a6ab5..c226f93 100644
--- a/test/lib/test_mli_parser.ml
+++ b/test/lib/test_mli_parser.ml
@@ -101,7 +101,7 @@ let test_parse_mli =
       ~expected:
         (Ok
            {x|[Text "(** This doc comment with a label should get parsed\n\n    ";
- Text "{@"; Text "ocaml"; Text " "; Text "skip "; Text "[";
+ Text "{@"; Text "ocaml"; Text " "; Text "skip"; Text "[";
  Block {loc: File "_none_", lines 3-6; section: None; labels: [skip];
         header: Some ocaml; contents: ["# 1 + 1"; "- : int = 2"];
         value: Toplevel};

[Leonidas-from-XIV]

I'm not happy that all the blocks need to know whether they are Syntax.Mli or not to print the proper padding because it it incredibly fussy and the cyclomatic complexity is through the roof but it is… not worse than before and at least Cram.t in .mli files should be displayed properly.

I suggest revisiting our Markdown parsering some time down the road to make it more similar to what we get from odoc-parser and try to avoid all this switching logic but for now I think this is ok to be reviewed and actually also fixes the Cram.t printing bug that @Julow found.

[Julow]

LGTM :)

I've sent a patch to your branch but it can wait until the next refactoring: https://github.com/Leonidas-from-XIV/mdx/pull/1

[Leonidas-from-XIV]

We discussed this with @Julow and concluded that it is worth merging, hence I merged it.