Don't escape @ in the middle of a word

CHANGES.md

@@ -27,6 +27,7 @@
 
 ### Changes
 
+- Improve escaping of `@` in doc-comments (#2377, @Julow)
 - Disable reporting of deprecated alerts while formatting code blocks (#2373, @Julow)
 - Improve indentation of `as`-patterns (#2359, @Julow)
 - Restore short form for first-class modules: `((module M) : (module S))` is formatted as `(module M : S)`) (#2280, #2300, @gpetiot, @Julow)

lib/Fmt_odoc.ml

@@ -43,10 +43,7 @@ let escape_brackets s =
   ensure_escape ~escapeworthy s
 
 let escape_all s =
-  let escapeworthy = function
-    | '@' | '{' | '}' | '[' | ']' -> true
-    | _ -> false
-  in
+  let escapeworthy = function '{' | '}' | '[' | ']' -> true | _ -> false in
   ensure_escape ~escapeworthy s
 
 let split_on_whitespaces =
@@ -177,22 +174,19 @@ let rec fmt_inline_elements c elements =
   in
   let rec aux = function
     | [] -> noop
-    | `Space sp :: `Word w :: t ->
-        (* Escape lines starting with '+' or '-' *)
-        let escape =
-          if String.length w > 0 && Char.(w.[0] = '+' || w.[0] = '-') then
-            "\\"
-          else ""
-        in
+    | `Space sp :: `Word (("-" | "+") as w) :: t ->
+        (* Escape lines starting with '+' or '-'. *)
         fmt_or_k c.conf.fmt_opts.wrap_docstrings.v
-          (cbreak ~fits:("", 1, "") ~breaks:("", 0, escape))
+          (cbreak ~fits:("", 1, "") ~breaks:("", 0, "\\"))
           (non_wrap_space sp)
-        $ str_normalized c w $ aux t
+        $ str w $ aux t
     | `Space sp :: t ->
         fmt_or_k c.conf.fmt_opts.wrap_docstrings.v (fmt "@ ")
           (non_wrap_space sp)
         $ aux t
-    | `Word w :: t -> str_normalized c w $ aux t
+    | `Word w :: t ->
+        fmt_if (String.is_prefix ~prefix:"@" w) "\\"
+        $ str_normalized c w $ aux t
     | `Code_span s :: t -> fmt_code_span s $ aux t
     | `Math_span s :: t -> fmt_math_span s $ aux t
     | `Raw_markup (lang, s) :: t ->

test/passing/tests/doc_comments-no-parse-docstrings.mli.ref

@@ -630,3 +630,7 @@ type x =
 
 (** ISO-Latin1 characters in identifiers
     {[ω]}*)
+
+(** at@ *)
+
+(** \@at *)

test/passing/tests/doc_comments-no-wrap.mli.ref

@@ -636,3 +636,7 @@ type x =
     {[
       ω
     ]}*)
+
+(** at@ *)
+
+(** \@at *)

test/passing/tests/doc_comments.mli

@@ -638,3 +638,6 @@ type x =
 
 (** ISO-Latin1 characters in identifiers
     {[ω]}*)
+
+(** at@ *)
+(** \@at *)

test/passing/tests/doc_comments.mli.ref

@@ -630,3 +630,7 @@ type x =
     {[
       ω
     ]}*)
+
+(** at@ *)
+
+(** \@at *)