Do error checks inside Python interop classes

src/CSnakes.Runtime/CPython/Float.cs

@@ -15,13 +15,23 @@ internal unsafe partial class CPythonAPI
     [LibraryImport(PythonLibraryName)]
     internal static partial nint PyFloat_FromDouble(double value);
 
+    internal static double PyFloat_AsDouble(PyObject p)
+    {
+        double result = PyFloat_AsDouble_(p);
+        if (result == -1 && PyErr_Occurred())
+        {
+            throw PyObject.ThrowPythonExceptionAsClrException("Error converting Python object to double, check that the object was a Python float. See InnerException for details.");
+        }
+        return result;
+    }
+
     /// <summary>
     /// Convery a PyFloat to a C double
     /// </summary>
     /// <param name="p"></param>
     /// <returns>The double value</returns>
-    [LibraryImport(PythonLibraryName)]
-    internal static partial double PyFloat_AsDouble(PyObject obj);
+    [LibraryImport(PythonLibraryName, EntryPoint = "PyFloat_AsDouble")]
+    private static partial double PyFloat_AsDouble_(PyObject obj);
 
     internal static bool IsPyFloat(PyObject p)
     {

src/CSnakes.Runtime/CPython/Long.cs

@@ -13,11 +13,41 @@ internal unsafe partial class CPythonAPI
     [LibraryImport(PythonLibraryName)]
     internal static partial nint PyLong_FromLongLong(long v);
 
-    [LibraryImport(PythonLibraryName)]
-    internal static partial long PyLong_AsLongLong(PyObject p);
+    /// <summary>
+    /// Calls PyLong_AsLongLong and throws a Python Exception if an error occurs.
+    /// </summary>
+    /// <param name="p"></param>
+    /// <returns></returns>
+    internal static long PyLong_AsLongLong(PyObject p)
+    {
+        long result = PyLong_AsLongLong_(p);
+        if (result == -1 && PyErr_Occurred())
+        {
+            throw PyObject.ThrowPythonExceptionAsClrException("Error converting Python object to int, check that the object was a Python int or that the value wasn't too large. See InnerException for details.");
+        }
+        return result;
+    }
 
-    [LibraryImport(PythonLibraryName)]
-    internal static partial int PyLong_AsLong(PyObject p);
+    [LibraryImport(PythonLibraryName, EntryPoint = "PyLong_AsLongLong")]
+    private static partial long PyLong_AsLongLong_(PyObject p);
+
+    /// <summary>
+    /// Calls PyLong_AsLong and throws a Python Exception if an error occurs.
+    /// </summary>
+    /// <param name="p"></param>
+    /// <returns></returns>
+    internal static long PyLong_AsLong(PyObject p)
+    {
+        long result = PyLong_AsLong_(p);
+        if (result == -1 && PyErr_Occurred())
+        {
+            throw PyObject.ThrowPythonExceptionAsClrException("Error converting Python object to int, check that the object was a Python int or that the value wasn't too large. See InnerException for details.");
+        }
+        return result;
+    }
+
+    [LibraryImport(PythonLibraryName, EntryPoint = "PyLong_AsLong")]
+    private static partial int PyLong_AsLong_(PyObject p);
 
     internal static bool IsPyLong(PyObject p)
     {

src/CSnakes.Runtime/CPython/Unicode.cs

@@ -17,6 +17,11 @@ internal static nint AsPyUnicodeObject(string s)
     [LibraryImport(PythonLibraryName)]
     internal static partial nint PyUnicode_DecodeUTF16(char* str, nint size, IntPtr errors, IntPtr byteorder);
 
+    /// <summary>
+    /// Calls PyUnicode_AsUTF8 and throws a Python Exception if an error occurs.
+    /// </summary>
+    /// <param name="s"></param>
+    /// <returns></returns>
     internal static string PyUnicode_AsUTF8(PyObject s)
     {
         var result = PyUnicode_AsUTF8_(s);