Added boost::optional support for using with Boost.Python.

3 files changed, 93 insertions, 18 deletions

diff --git a/src/py_amount.cc b/src/py_amount.cc
index 61e3e4b5..c4f476c3 100644
--- a/src/py_amount.cc
+++ b/src/py_amount.cc
@@ -1,7 +1,9 @@
 #include "pyinterp.h"
+#include "pyutils.h"
 #include "amount.h"
 
 #include <boost/python/exception_translator.hpp>
+#include <boost/python/implicit.hpp>
 
 namespace ledger {
 
@@ -21,6 +23,14 @@ amount_t py_round_2(const amount_t& amount) {
   return amount.round();
 }
 
+boost::optional<amount_t> py_value_1(const amount_t& amount,
+				     const boost::optional<moment_t>& moment) {
+  return amount.value(moment);
+}
+boost::optional<amount_t> py_value_2(const amount_t& amount) {
+  return amount.value();
+}
+
 #define EXC_TRANSLATOR(type)				\
   void exc_translate_ ## type(const type& err) {	\
     PyErr_SetString(PyExc_ArithmeticError, err.what());	\
@@ -161,7 +171,8 @@ void export_amount()
     .def("in_place_unreduce", &amount_t::in_place_unreduce,
 	 return_value_policy<reference_existing_object>())
 
-    .def("value", &amount_t::value)
+    .def("value", py_value_1)
+    .def("value", py_value_2)
 
     .def("sign", &amount_t::sign)
     .def("__nonzero__", &amount_t::nonzero)
@@ -213,6 +224,12 @@ void export_amount()
     .def("valid", &amount_t::valid)
     ;
 
+  python_optional<amount_t>();
+
+  implicitly_convertible<double, amount_t>();
+  implicitly_convertible<long, amount_t>();
+  implicitly_convertible<string, amount_t>();
+
 #define EXC_TRANSLATE(type) \
   register_exception_translator<type>(&exc_translate_ ## type);
 
diff --git a/src/py_times.cc b/src/py_times.cc
index 578d887b..f509e0d0 100644
--- a/src/py_times.cc
+++ b/src/py_times.cc
@@ -9,6 +9,8 @@
 #include <Python.h>
 #include <datetime.h>
 
+// jww (2007-05-04): Convert time duration objects to PyDelta
+
 namespace ledger {
 
 using namespace boost::python;
@@ -29,7 +31,7 @@ struct date_from_python
   static void* convertible(PyObject* obj_ptr)
   {
     PyDateTime_IMPORT;
-    if(PyDate_Check(obj_ptr) || PyDateTime_Check(obj_ptr)) return obj_ptr;
+    if (PyDate_Check(obj_ptr)) return obj_ptr;
     return 0;
   }
 
@@ -48,15 +50,13 @@ typedef register_python_conversion<date, date_to_python, date_from_python>
   date_python_conversion;
 
 
-typedef boost::posix_time::ptime datetime;
-
 struct datetime_to_python
 {
-  static PyObject* convert(const datetime& moment)
+  static PyObject* convert(const moment_t& moment)
   {
     PyDateTime_IMPORT;
     date dte = moment.date();
-    datetime::time_duration_type tod = moment.time_of_day();
+    moment_t::time_duration_type tod = moment.time_of_day();
     return PyDateTime_FromDateAndTime(dte.year(), dte.month(), dte.day(),
 				      tod.hours(), tod.minutes(), tod.seconds(),
 				      tod.total_microseconds() % 1000000);
@@ -81,19 +81,21 @@ struct datetime_from_python
     int h = PyDateTime_DATE_GET_HOUR(obj_ptr);
     int min = PyDateTime_DATE_GET_MINUTE(obj_ptr);
     int s = PyDateTime_DATE_GET_SECOND(obj_ptr);
-    datetime* moment = new datetime(date(y,m,d),
-				    datetime::time_duration_type(h, min, s));
+    moment_t* moment = new moment_t(date(y,m,d),
+				    moment_t::time_duration_type(h, min, s));
     data->convertible = (void*)moment;
   }
 };
 
-typedef register_python_conversion<datetime, datetime_to_python, datetime_from_python>
+typedef register_python_conversion<moment_t, datetime_to_python, datetime_from_python>
   datetime_python_conversion;
 
 void export_times()
 {
   date_python_conversion();
   datetime_python_conversion();
+
+  python_optional<moment_t>();
 }
 
 } // namespace ledger
diff --git a/src/pyutils.h b/src/pyutils.h
index 4ff33f8f..84a0db7e 100644
--- a/src/pyutils.h
+++ b/src/pyutils.h
@@ -1,22 +1,78 @@
 #ifndef _PY_UTILS_H
 #define _PY_UTILS_H
 
-template<class T, class TfromPy>
-struct ObjFromPy {
-  ObjFromPy() {
+template <typename T, typename TfromPy>
+struct object_from_python
+{
+  object_from_python() {
     boost::python::converter::registry::push_back
-	  (&TfromPy::convertible,
-	   &TfromPy::construct,
-	   boost::python::type_id<T>());
+      (&TfromPy::convertible, &TfromPy::construct,
+       boost::python::type_id<T>());
   }
 };
 
-template<class T, class TtoPy, class TfromPy>
-struct register_python_conversion {
+template <typename T, typename TtoPy, typename TfromPy>
+struct register_python_conversion
+{
   register_python_conversion() {
     boost::python::to_python_converter<T, TtoPy>();
-    ObjFromPy<T, TfromPy>();
+    object_from_python<T, TfromPy>();
   }
 };
 
+template <typename T>
+struct python_optional : public boost::noncopyable
+{
+  struct optional_to_python
+  {
+    static PyObject * convert(const boost::optional<T>& value)
+    {
+      return (value ? boost::python::to_python_value<T>()(*value) :
+	              boost::python::detail::none());
+    }
+  };
+   
+  struct optional_from_python
+  {
+    static void * convertible(PyObject * source)
+    {
+      using namespace boost::python::converter;
+
+      if (source == Py_None)
+	return source;
+
+      const registration& converters(registered<T>::converters);
+
+      if (implicit_rvalue_convertible_from_python(source, converters)) {
+	rvalue_from_python_stage1_data data =
+	  rvalue_from_python_stage1(source, converters);
+	return rvalue_from_python_stage2(source, data, converters);
+      }
+      return NULL;
+    }
+
+    static void construct(PyObject * source,
+			  boost::python::converter::rvalue_from_python_stage1_data * data)
+    {
+      using namespace boost::python::converter;
+
+      void * const storage = ((rvalue_from_python_storage<T> *) data)->storage.bytes;
+
+      if (data->convertible == source)	    // == None
+	new (storage) boost::optional<T>(); // A Boost uninitialized value
+      else
+	new (storage) boost::optional<T>(*static_cast<T *>(data->convertible));
+
+      data->convertible = storage;
+    }
+  };
+
+  explicit python_optional() {
+    register_python_conversion<boost::optional<T>,
+      optional_to_python, optional_from_python>();
+  }
+};
+
+//boost::python::register_ptr_to_python< boost::shared_ptr<Base> >();
+
 #endif // _PY_UTILS_H