fix SetLinearSolver in arkode

Author: balos1

bindings/pysundials/arkode/generate.yaml

@@ -25,6 +25,9 @@ modules:
     macro_define_include_by_name__regex:
     - "^SUN_"
     - "^ARK_"
+    fn_params_optional_with_default_null:
+      "SetLinearSolver":
+      - "A" 
   arkode:
     path: arkode/pysundials_arkode_generated.hpp
     headers:
@@ -45,6 +48,8 @@ modules:
     - "ARKodeSetWFtolerances"
     - "ARKodeSet.*Preconditioner"
     - "ARKodeSet.*Times"
+    # generator cannot handle functions with optional (i.e. NULLable) parameters that is not followed by only optional parameters
+    - "ARKodeSetMassLinearSolver"
   arkstep:
     path: arkode/pysundials_arkode_arkstep_generated.hpp
     headers:

bindings/pysundials/arkode/pysundials_arkode.cpp

@@ -12,8 +12,11 @@
  * SUNDIALS Copyright End
  *----------------------------------------------------------------------------*/
 
+#include <optional>
+
 #include <nanobind/nanobind.h>
 #include <nanobind/stl/function.h>
+#include <nanobind/stl/optional.h>
 
 #include <sundials/sundials_core.hpp>
 
@@ -44,7 +47,9 @@ void bind_arkode(nb::module_& m)
     .def("get", nb::overload_cast<>(&ARKodeView::get, nb::const_),
          nb::rv_policy::reference);
 
+  //
   // ARKode function pointer setters
+  //
   m.def("ARKodeSetPostprocessStepFn",
         [](void* ark_mem, std::function<std::remove_pointer_t<ARKPostProcessFn>> fn)
         {
@@ -240,6 +245,15 @@ void bind_arkode(nb::module_& m)
           return ARKodeSetLinSysFn(ark_mem, &arkode_lslinsysfn_wrapper);
         });
 
+  /////////////////////////////////////////////////////////////////////////////
+  // Additional functions that litgen cannot generate
+  /////////////////////////////////////////////////////////////////////////////
+
+  // These functions have optional arguments which litgen cannot deal with
+  m.def("ARKodeSetMassLinearSolver",
+    ARKodeSetMassLinearSolver, nb::arg("arkode_mem"), nb::arg("LS"), nb::arg("M").none(), nb::arg("time_dep"));
+
+
   bind_arkode_arkstep(m);
   bind_arkode_erkstep(m);
   bind_arkode_sprkstep(m);

bindings/pysundials/arkode/pysundials_arkode_generated.hpp

@@ -471,10 +471,20 @@ m.def("ARKodeGetNumRelaxSolveIters",
 // 
 
 m.def("ARKodeSetLinearSolver",
-    ARKodeSetLinearSolver, nb::arg("arkode_mem"), nb::arg("LS"), nb::arg("A"));
-
-m.def("ARKodeSetMassLinearSolver",
-    ARKodeSetMassLinearSolver, nb::arg("arkode_mem"), nb::arg("LS"), nb::arg("M"), nb::arg("time_dep"));
+    [](void * arkode_mem, SUNLinearSolver LS, std::optional<SUNMatrix> A = std::nullopt) -> int
+    {
+        auto ARKodeSetLinearSolver_adapt_optional_arg_with_default_null = [](void * arkode_mem, SUNLinearSolver LS, std::optional<SUNMatrix> A = std::nullopt) -> int
+        {
+            SUNMatrix A_adapt_default_null = nullptr;
+            if (A.has_value())
+                A_adapt_default_null = A.value();
+
+            auto lambda_result = ARKodeSetLinearSolver(arkode_mem, LS, A_adapt_default_null);
+            return lambda_result;
+        };
+
+        return ARKodeSetLinearSolver_adapt_optional_arg_with_default_null(arkode_mem, LS, A);
+    },     nb::arg("arkode_mem"), nb::arg("LS"), nb::arg("A") = nb::none());
 
 m.def("ARKodeSetJacEvalFrequency",
     ARKodeSetJacEvalFrequency, nb::arg("arkode_mem"), nb::arg("msbj"));