unikernel/duniverse/ppxlib/test/error_embedding/deriver.ml

@@ -0,0 +1,32 @@
+open Ppxlib
+
+let derive_a_string ~ctxt (_rec_flag, _type_declarations) =
+  let loc = Expansion_context.Deriver.derived_item_loc ctxt in
+  let open Ast_builder.Default in
+  [
+    pstr_value ~loc Nonrecursive
+      [
+        {
+          pvb_pat = ppat_any ~loc;
+          pvb_expr = estring ~loc "derived_string";
+          pvb_attributes = [];
+          pvb_loc = loc;
+          pvb_constraint = None;
+        };
+      ];
+  ]
+
+let impl_generator_derive_a_string =
+  Deriving.Generator.V2.make_noarg derive_a_string
+
+let deriver_for_a_string =
+  Deriving.add "a_string" ~str_type_decl:impl_generator_derive_a_string
+
+let impl_generator_dependent =
+  Deriving.Generator.V2.make_noarg ~deps:[ deriver_for_a_string ]
+    derive_a_string
+
+let _dependent_deriver =
+  Deriving.add "a_dependent_string" ~str_type_decl:impl_generator_dependent
+
+let () = Driver.standalone ()