Rework exception handling & more instances for conversion

cbits/python.c

@@ -1,32 +1,6 @@
 #include <inline-python.h>
 #include <stdlib.h>
 
-void inline_py_export_exception(
-    PyObject *e_type,
-    PyObject *e_value,
-    PyObject *e_trace,
-    char** p_msg
-    )
-{
-    // Convert to python string object
-    PyObject *e_str = PyObject_Str(e_value);
-    if( 0 == e_str ) {
-        *p_msg = 0;
-        return;
-    }
-    // Convert to UTF8 C string
-    const char *err_msg = PyUnicode_AsUTF8(e_str);
-    if( 0 == e_str ) {
-        *p_msg = 0;
-        return;
-    }
-    // Copy message
-    int n  = strlen(err_msg);
-    *p_msg = malloc(n+1);
-    strcpy(*p_msg, err_msg);
-    return;
-}
-
 PyObject *inline_py_function_wrapper(PyCFunction fun, int flags) {
     PyMethodDef *meth = malloc(sizeof(PyMethodDef));
     meth->ml_name  = "[inline_python]";
@@ -44,18 +18,20 @@ PyObject *inline_py_function_wrapper(PyCFunction fun, int flags) {
 }
 
 int inline_py_unpack_iterable(PyObject *iterable, int n, PyObject **out) {
-    // Fill out with NULL. This way we can call XDECREF on them
-    for(int i = 0; i < n; i++) {
-        out[i] = NULL;
-    }
-    // Initialize iterator
+    // Initialize iterator. If object is not an iterable we treat this
+    // as not an exception but as a conversion failure
     PyObject* iter = PyObject_GetIter( iterable );
     if( PyErr_Occurred() ) {
+        PyErr_Clear();
         return -1;
     }
     if( !PyIter_Check(iter) ) {
         goto err_iter;
     }
+    // Fill out with NULL. This way we can call XDECREF on them
+    for(int i = 0; i < n; i++) {
+        out[i] = NULL;
+    }
     // Fill elements
     for(int i = 0; i < n; i++) {
         out[i] = PyIter_Next(iter);
@@ -81,7 +57,6 @@ int inline_py_unpack_iterable(PyObject *iterable, int n, PyObject **out) {
     return -1;
 }
 
-
 void inline_py_free_capsule(PyObject* py) {
     PyMethodDef *meth = PyCapsule_GetPointer(py, NULL);
     // HACK: We want to release wrappers created by wrapper. It

include/inline-python.h

@@ -5,40 +5,23 @@
 #include <Rts.h>
 
 
-// Standard status codesu
-#define INLINE_PY_OK          0
-#define INLINE_PY_ERR_COMPILE 1
-#define INLINE_PY_ERR_EVAL    2
-
-
-
-// This macro checks for errors. If python exception is raised it
-// clear it and returns 1 otherwise retruns 0
-#define INLINE_PY_SIMPLE_ERROR_HANDLING() do {      \
-    if( PyErr_Occurred() ) {                        \
-          PyObject *e_type, *e_value, *e_trace;     \
-          PyErr_Fetch(&e_type, &e_value, &e_trace); \
-          return 1;                                 \
-    }                                               \
-    return 0;                                       \
-} while(0)
-
-// Convert python exception into form suitable for haskell
-void inline_py_export_exception(
-    PyObject *e_type,
-    PyObject *e_value,
-    PyObject *e_trace,
-    char** p_msg
-    );
+// ----------------------------------------------------------------
+// Standard status codes
+
+#define IPY_OK          0
+#define IPY_ERR_PYTHON  1
+#define IPY_ERR_COMPILE 2
+
+// ----------------------------------------------------------------
 
 // Unpack iterable into array of PyObjects. Iterable must contain
 // exactly N elements.
 //
 // On success returns 0 and fills `out` with N PyObjects
 //
-// On failure returns -1. Python exception is not cleared. It's
-// responsibility of caller to deal with it. Content of `out` is
-// undefined in this case.
+// On failure return -1. Content of out is then undefined and it
+// doesn't contain live python objects. If failure is due to python
+// exception it's not cleared.
 int inline_py_unpack_iterable(
     PyObject  *iterable,
     int        n,

inline-python.cabal

@@ -38,6 +38,7 @@ common language
     PatternSynonyms
     ViewPatterns
     LambdaCase
+    MultiWayIf
     --
     NoFieldSelectors
     DuplicateRecordFields
@@ -66,10 +67,11 @@ Library
     Python.Inline
     Python.Types
   Other-modules:
-    Python.Internal.Types
-    Python.Internal.Util
     Python.Internal.Eval
     Python.Internal.EvalQQ
+    Python.Internal.Program
+    Python.Internal.Types
+    Python.Internal.Util
     Paths_inline_python
   Autogen-modules:
     Paths_inline_python
@@ -84,6 +86,7 @@ library test
   hs-source-dirs:   test
   Exposed-modules:
     TST.Run
+    TST.ToPy
     TST.FromPy
 
 test-suite inline-python-tests

src/Python/Inline.hs

@@ -8,7 +8,9 @@ module Python.Inline
   , ToPy(..)
   , FromPy(..)
   , toPy
+  , fromPyEither
   , fromPy
+  , fromPy'
   ) where