fix #5557

Author: bobzhang

CHANGELOG.md

@@ -28,6 +28,10 @@
 
 - Fix issue where async as an id cannot be used with application and labelled arguments https://github.com/rescript-lang/syntax/issues/707
 
+- Fix 5557 the exhaustive checking for Char is incorrect during the unicode migration
+
+- Fix 5753 the comment for unicode char is inaccurate
+
 # 10.1.0-rc.2
 
 #### :bug: Bug Fix

jscomp/ml/parmatch.ml

@@ -1037,7 +1037,7 @@ let build_other_constant proj make first next p env =
 
 let some_other_tag = "<some other tag>"
 
-let build_other ext env = match env with
+let build_other ext env : Typedtree.pattern = match env with
 | ({pat_desc = Tpat_construct (lid, {cstr_tag=Cstr_extension _},_)},_) :: _ ->
         (* let c = {c with cstr_name = "*extension*"} in *) (* PR#7330 *)
         make_pat (Tpat_var (Ident.create "*extension*",
@@ -1079,13 +1079,19 @@ let build_other ext env = match env with
             make_pat (Tpat_or (pat, p_res, None)) p.pat_type p.pat_env)
           pat other_pats
     end
-| ({pat_desc=(Tpat_constant (Const_int _ | Const_char _))} as p,_) :: _ ->
+| ({pat_desc=(Tpat_constant (Const_int _ ))} as p,_) :: _ ->
     build_other_constant
       (function Tpat_constant(Const_int i) -> i 
-      | Tpat_constant (Const_char i) -> Char.code i
       | _ -> assert false)
       (function i -> Tpat_constant(Const_int i))
       0 succ p env
+| ({pat_desc=(Tpat_constant (Const_char _ ))} as p,_) :: _ ->
+        build_other_constant
+          (function 
+          | Tpat_constant (Const_char i) -> i
+          | _ -> assert false)
+          (function i -> Tpat_constant(Const_char i))
+          0 succ p env      
 | ({pat_desc=(Tpat_constant (Const_int32 _))} as p,_) :: _ ->
     build_other_constant
       (function Tpat_constant(Const_int32 i) -> i | _ -> assert false)

jscomp/napkin/CHANGELOG.md

@@ -59,6 +59,7 @@
 #### :nail_care Polish
 
 - Change the internal representation of props for the lowercase components to record. https://github.com/rescript-lang/syntax/pull/665
+- Change the payload of Pconst_char for type safety. https://github.com/rescript-lang/rescript-compiler/pull/5759
 
 ## ReScript 10.0