Fix missing parens for polymorphic arguments

art-w · panglesd · commit f91e2ab59361 · 2026-04-13T18:31:03.000+02:00
diff --git a/src/document/generator.ml b/src/document/generator.ml
@@ -446,7 +446,7 @@ module Make (Syntax : SYNTAX) = struct
             ++ O.sp ++ type_expr dst
             (* ++ O.end_hv *)
           in
-          if not needs_parentheses then res else enclose ~l:"(" res ~r:")"
+          enclose_parens_if_needed res
       | Arrow (Some (RawOptional _ as lbl), _src, dst) ->
           let res =
             O.span
@@ -456,7 +456,7 @@ module Make (Syntax : SYNTAX) = struct
                  ++ O.txt " " ++ Syntax.Type.arrow)
             ++ O.sp ++ type_expr dst
           in
-          if not needs_parentheses then res else enclose ~l:"(" res ~r:")"
+          enclose_parens_if_needed res
       | Arrow (Some lbl, src, dst) ->
           let res =
             O.span
@@ -466,7 +466,7 @@ module Make (Syntax : SYNTAX) = struct
               ++ O.txt " " ++ Syntax.Type.arrow)
             ++ O.sp ++ type_expr dst
           in
-          if not needs_parentheses then res else enclose ~l:"(" res ~r:")"
+          enclose_parens_if_needed res
       | Tuple lst -> tuple ~needs_parentheses ~boxed:true lst
       | Unboxed_tuple lst -> tuple ~needs_parentheses ~boxed:false lst
       | Constr (path, args) ->
@@ -478,7 +478,9 @@ module Make (Syntax : SYNTAX) = struct
           format_type_path ~delim:`brackets args
             (Link.from_path (path :> Paths.Path.t))
       | Poly (polyvars, t) ->
-          O.txt ("'" ^ String.concat ~sep:" '" polyvars ^ ". ") ++ type_expr t
+          enclose_parens_if_needed
+          @@ O.txt ("'" ^ String.concat ~sep:" '" polyvars ^ ". ")
+             ++ type_expr t
       | Quote t -> O.span (O.txt "<[ " ++ O.box_hv (type_expr t) ++ O.txt " ]>")
       | Splice t -> O.span (O.txt "$" ++ type_expr ~needs_parentheses:true t)
       | Package pkg ->
diff --git a/test/generators/cases/ocaml_55.mli b/test/generators/cases/ocaml_55.mli
@@ -17,3 +17,5 @@ val g : (module M : Y) -> int M.t
 val g' : (module M : Y) -> int
 
 val g'' : (module Y) -> int
+
+val map2: ('a. 'a -> 'a) -> 'a * 'b -> 'a * 'b
diff --git a/test/generators/html/Ocaml_55.html b/test/generators/html/Ocaml_55.html
@@ -148,6 +148,28 @@ <h1>Module <code><span>Ocaml_55</span></code></h1>
      </code>
     </div>
    </div>
+   <div class="odoc-spec">
+    <div class="spec value anchored" id="val-map2">
+     <a href="#val-map2" class="anchor"></a>
+     <code>
+      <span><span class="keyword">val</span> map2 : 
+       <span>
+        <span>('a. 
+         <span><span class="type-var">'a</span> 
+          <span class="arrow">&#45;&gt;</span>
+         </span> <span class="type-var">'a</span>)
+        </span> <span class="arrow">&#45;&gt;</span>
+       </span> 
+       <span>
+        <span>(<span class="type-var">'a</span> * 
+         <span class="type-var">'b</span>)
+        </span> <span class="arrow">&#45;&gt;</span>
+       </span> <span class="type-var">'a</span> * 
+       <span class="type-var">'b</span>
+      </span>
+     </code>
+    </div>
+   </div>
   </div>
  </body>
 </html>
