1 files changed, 18 insertions, 18 deletions
diff --git a/lib/syntax/catalog.ml b/lib/syntax/catalog.ml
index b516976..5ad0bbd 100644
--- a/lib/syntax/catalog.ml
+++ b/lib/syntax/catalog.ml
@@ -18,31 +18,31 @@ type ex =
       -> ex  (** Type of check to apply *)
 
 let build :
+    ?location_id:'a Type.Id.t ->
+    ?context_id:'b Type.Id.t ->
     (module S.Analyzer
        with type Expression.t = _
         and type Expression.t' = _
         and type Instruction.t = _
         and type Instruction.t' = _
         and type Location.t = 'a
-        and type context = _) ->
-    'a Type.Id.t * ex =
- fun module_ ->
+        and type context = 'b) ->
+    ex =
+ fun ?location_id ?context_id module_ ->
   let expr_witness = Type.Id.make ()
   and expr' = Type.Id.make ()
   and instr_witness = Type.Id.make ()
   and instr' = Type.Id.make ()
-  and location_witness = Type.Id.make ()
-  and context = Type.Id.make () in
-  let t =
-    E
-      {
-        module_;
-        expr_witness;
-        expr';
-        instr_witness;
-        instr';
-        location_witness;
-        context;
-      }
-  in
-  (location_witness, t)
+  and location_witness =
+    match location_id with Some v -> v | None -> Type.Id.make ()
+  and context = match context_id with Some v -> v | None -> Type.Id.make () in
+  E
+    {
+      module_;
+      expr_witness;
+      expr';
+      instr_witness;
+      instr';
+      location_witness;
+      context;
+    }