Create a py_value module, for translating value_t objects to/from Python.

2 files changed, 92 insertions, 15 deletions

diff --git a/python/py_value.cc b/python/py_value.cc
new file mode 100644
index 00000000..419d635d
--- /dev/null
+++ b/python/py_value.cc
@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2003-2009, John Wiegley.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * - Neither the name of New Artisans LLC nor the names of its
+ *   contributors may be used to endorse or promote products derived from
+ *   this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "pyinterp.h"
+#include "pyutils.h"
+#include "value.h"
+
+#include <boost/python/exception_translator.hpp>
+#include <boost/python/implicit.hpp>
+#include <boost/python/args.hpp>
+
+namespace ledger {
+
+using namespace boost::python;
+
+#define EXC_TRANSLATOR(type)				\
+  void exc_translate_ ## type(const type& err) {	\
+    PyErr_SetString(PyExc_ArithmeticError, err.what());	\
+  }
+
+EXC_TRANSLATOR(value_error)
+
+void export_value()
+{
+#if 0
+      if (PyBool_Check(func.ptr()))
+	return extract<bool>(func)();
+      else if (PyInt_Check(func.ptr()))
+	return long(extract<int>(func)());
+      else if (PyString_Check(func.ptr()))
+	return string_value(extract<string>(func)());
+
+      extract<date_t> d(func);
+      if (d.check())
+	return value_t(d());
+      extract<datetime_t> dt(func);
+      if (dt.check())
+	return value_t(dt());
+#endif
+
+  register_optional_to_python<value_t>();
+
+#ifdef HAVE_GDTOA
+  implicitly_convertible<double, value_t>();
+#endif
+  implicitly_convertible<long, value_t>();
+  implicitly_convertible<string, value_t>();
+
+#define EXC_TRANSLATE(type) \
+  register_exception_translator<type>(&exc_translate_ ## type);
+
+  EXC_TRANSLATE(value_error);
+}
+
+} // namespace ledger
diff --git a/python/pyinterp.cc b/python/pyinterp.cc
index 582b8e78..6af17170 100644
--- a/python/pyinterp.cc
+++ b/python/pyinterp.cc
@@ -43,7 +43,9 @@ void export_amount();
 void export_commodity();
 #if 0
 void export_balance();
+#endif
 void export_value();
+#if 0
 void export_journal();
 void export_parser();
 void export_option();
@@ -61,7 +63,9 @@ void initialize_for_python()
   export_commodity();
 #if 0
   export_balance();
+#endif
   export_value();
+#if 0
   export_journal();
   export_parser();
   export_option();
@@ -223,21 +227,11 @@ value_t python_interpreter_t::functor_t::operator()(call_scope_t& args)
 {
   try {
     if (! PyCallable_Check(func.ptr())) {
-      if (PyBool_Check(func.ptr()))
-	return extract<bool>(func)();
-      else if (PyInt_Check(func.ptr()))
-	return long(extract<int>(func)());
-      else if (PyString_Check(func.ptr()))
-	return string_value(extract<string>(func)());
-
-      extract<date_t> d(func);
-      if (d.check())
-	return value_t(d());
-      extract<datetime_t> dt(func);
-      if (dt.check())
-	return value_t(dt());
-
-      return extract<value_t>(func);
+      extract<value_t> val(func);
+      if (val.check())
+	return val();
+      throw_(calc_error,
+	     "Could not evaluate Python variable '" << name << "'");
     } else {
       if (args.size() > 0) {
 	list arglist;