From: stevenj <stevenj@alum.mit.edu>
Date: Sun, 13 Jun 2010 01:39:28 +0000 (-0400)
Subject: handle/throw Python exceptions
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=58af4582a6a4425b6ccb3e25fe947a496217557e;p=nlopt.git

handle/throw Python exceptions

darcs-hash:20100613013928-c8de0-d1e6780ef8c07f7d9f49e0d4636661df1d5a2890.gz
---

diff --git a/swig/nlopt-python.i b/swig/nlopt-python.i
index 8a2e88e..37fdabc 100644
--- a/swig/nlopt-python.i
+++ b/swig/nlopt-python.i
@@ -1,5 +1,61 @@
 // -*- C++ -*-
 
+//////////////////////////////////////////////////////////////////////////////
+// Converting NLopt/C++ exceptions to Python exceptions
+
+%{
+
+#define ExceptionSubclass(EXCNAME, EXCDOC)				\
+  static PyTypeObject MyExc_ ## EXCNAME = {				\
+    PyObject_HEAD_INIT(NULL)						\
+      0,								\
+      "nlopt." # EXCNAME,						\
+      sizeof(PyBaseExceptionObject),					\
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,			\
+      Py_TPFLAGS_DEFAULT,						\
+      PyDoc_STR(EXCDOC)							\
+  };									\
+  static void init_ ## EXCNAME(PyObject *m) {				\
+    MyExc_ ## EXCNAME .tp_base = (PyTypeObject *) PyExc_Exception;	\
+    PyType_Ready(&MyExc_ ## EXCNAME);					\
+    Py_INCREF(&MyExc_ ## EXCNAME);					\
+    PyModule_AddObject(m, # EXCNAME, (PyObject *) &MyExc_ ## EXCNAME);	\
+  }
+
+
+ExceptionSubclass(ForcedStop,
+		  "Python version of nlopt::forced_stop exception.")
+
+ExceptionSubclass(RoundoffLimited,
+		  "Python version of nlopt::roundoff_limited exception.")
+
+%}
+
+%init %{
+  init_ForcedStop(m);
+  init_RoundoffLimited(m);
+%}
+%pythoncode %{
+  ForcedStop = _nlopt.ForcedStop
+  RoundoffLimited = _nlopt.RoundoffLimited
+%}
+
+%typemap(throws) std::bad_alloc %{
+  PyErr_SetString(PyExc_MemoryError, ($1).what());
+  SWIG_fail;
+%}
+
+%typemap(throws) nlopt::forced_stop %{
+  if (!PyErr_Occurred())
+    PyErr_SetString((PyObject*)&MyExc_ForcedStop, "NLopt forced stop");
+  SWIG_fail;
+%}
+
+%typemap(throws) nlopt::roundoff_limited %{
+  PyErr_SetString((PyObject*)&MyExc_RoundoffLimited, "NLopt roundoff-limited");
+  SWIG_fail;
+%}
+
 //////////////////////////////////////////////////////////////////////////////
 
 %{
@@ -81,7 +137,10 @@ static double func_python(unsigned n, const double *x, double *grad, void *f)
   Py_DECREF(xpy);
 
   double val = HUGE_VAL;
-  if (result && PyFloat_Check(result)) {
+  if (PyErr_Occurred()) {
+    throw nlopt::forced_stop(); // just stop, don't call PyErr_Clear()
+  }
+  else if (result && PyFloat_Check(result)) {
     val = PyFloat_AsDouble(result);
     Py_DECREF(result);
   }