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Python->C++ exception translation
[SVN r14800]
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8 files changed

+212
-2
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8 files changed

+212
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‎include/boost/python/detail/exception_handler.hpp‎

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// Copyright David Abrahams 2002. Permission to copy, use,
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// modify, sell and distribute this software is granted provided this
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// copyright notice appears in all copies. This software is provided
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// "as is" without express or implied warranty, and with no claim as
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// to its suitability for any purpose.
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#ifndef EXCEPTION_HANDLER_DWA2002810_HPP
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# define EXCEPTION_HANDLER_DWA2002810_HPP
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# include <boost/function/function0.hpp>
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# include <boost/function/function2.hpp>
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namespace boost { namespace python { namespace detail {
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struct BOOST_PYTHON_DECL exception_handler;
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typedef function2<bool, exception_handler const&, function0<void> const&> handler_function;
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struct BOOST_PYTHON_DECL exception_handler
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{
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private: // types
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public:
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explicit exception_handler(handler_function const& impl);
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inline bool handle(function0<void> const& f) const;
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bool operator()(function0<void> const& f) const;
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static exception_handler* chain;
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private:
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static exception_handler* tail;
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handler_function m_impl;
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exception_handler* m_next;
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};
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inline bool exception_handler::handle(function0<void> const& f) const
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{
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return this->m_impl(*this, f);
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}
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BOOST_PYTHON_DECL void register_exception_handler(handler_function const& f);
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}}} // namespace boost::python::detail
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#endif // EXCEPTION_HANDLER_DWA2002810_HPP

‎include/boost/python/detail/translate_exception.hpp‎

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// Copyright David Abrahams 2002. Permission to copy, use,
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// modify, sell and distribute this software is granted provided this
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// copyright notice appears in all copies. This software is provided
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// "as is" without express or implied warranty, and with no claim as
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// to its suitability for any purpose.
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#ifndef TRANSLATE_EXCEPTION_DWA2002810_HPP
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# define TRANSLATE_EXCEPTION_DWA2002810_HPP
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# include <boost/function/function0.hpp>
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# include <boost/call_traits.hpp>
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namespace boost { namespace python { namespace detail {
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struct exception_handler;
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// A ternary function object used to translate C++ exceptions of type
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// ExceptionType into Python exceptions by invoking an object of type
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// Translate. Typically the translate function will be curried with
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// boost::bind().
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template <class ExceptionType, class Translate>
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struct translate_exception
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{
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typedef typename add_reference<
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typename add_const<ExceptionType>::type
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>::type exception_cref;
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inline bool operator()(
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exception_handler const& handler
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, function0<void> const& f
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, typename call_traits<Translate>::param_type translate) const
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{
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try
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{
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return handler(f);
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}
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catch(exception_cref e)
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{
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translate(e);
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return true;
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}
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}
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};
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}}} // namespace boost::python::detail
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#endif // TRANSLATE_EXCEPTION_DWA2002810_HPP

‎include/boost/python/errors.hpp‎

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@@ -20,7 +20,7 @@ struct BOOST_PYTHON_DECL argument_error : error_already_set {};
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// Handles exceptions caught just before returning to Python code.
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// Returns true iff an exception was caught.
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BOOST_PYTHON_DECL bool handle_exception_impl(function0<void>);
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BOOST_PYTHON_DECL bool handle_exception_impl(function0<void> const&);
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template <class T>
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bool handle_exception(T f)

‎include/boost/python/exception_translator.hpp‎

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// Copyright David Abrahams 2002. Permission to copy, use,
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// modify, sell and distribute this software is granted provided this
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// copyright notice appears in all copies. This software is provided
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// "as is" without express or implied warranty, and with no claim as
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// to its suitability for any purpose.
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#ifndef EXCEPTION_TRANSLATOR_DWA2002810_HPP
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# define EXCEPTION_TRANSLATOR_DWA2002810_HPP
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# include <boost/python/detail/translate_exception.hpp>
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# include <boost/python/detail/exception_handler.hpp>
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# include <boost/type.hpp>
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# include <boost/bind.hpp>
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namespace boost { namespace python {
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template <class ExceptionType, class Translate>
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void register_exception_translator(Translate const& translate, boost::type<ExceptionType>* = 0)
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{
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detail::register_exception_handler(
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bind<bool>(detail::translate_exception<ExceptionType,Translate>(), _1, _2, translate)
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);
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}
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}} // namespace boost::python
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#endif // EXCEPTION_TRANSLATOR_DWA2002810_HPP

‎src/errors.cpp‎

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#include <boost/python/errors.hpp>
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#include <boost/cast.hpp>
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#ifdef BOOST_PYTHON_V2
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# include <boost/python/detail/exception_handler.hpp>
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#endif
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namespace boost { namespace python {
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// IMPORTANT: this function may only be called from within a catch block!
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BOOST_PYTHON_DECL bool handle_exception_impl(function0<void> f)
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BOOST_PYTHON_DECL bool handle_exception_impl(function0<void> const& f)
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{
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try
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{
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#ifdef BOOST_PYTHON_V2
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if (detail::exception_handler::chain)
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return detail::exception_handler::chain->handle(f);
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#endif
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f();
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return false;
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}
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// needed by void_adaptor (see void_adaptor.hpp)
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BOOST_PYTHON_DECL PyObject arbitrary_object = { 0 };
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#ifdef BOOST_PYTHON_V2
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bool exception_handler::operator()(function0<void> const& f) const
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{
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if (m_next)
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{
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return m_next->handle(f);
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}
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else
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{
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f();
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return false;
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}
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}
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exception_handler::exception_handler(handler_function const& impl)
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: m_impl(impl)
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, m_next(0)
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{
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if (chain != 0)
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tail->m_next = this;
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else
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chain = this;
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tail = this;
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}
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exception_handler* exception_handler::chain;
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exception_handler* exception_handler::tail;
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BOOST_PYTHON_DECL void register_exception_handler(handler_function const& f)
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{
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// the constructor links the new object into a handler chain, so
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// this object isn't actaully leaked (until, of course, the
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// interpreter exits).
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new exception_handler(f);
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}
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#endif
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} // namespace boost::python::detail
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‎test/Jamfile‎

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bpl-test minimal ;
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bpl-test docstring ;
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bpl-test exception_translator ;
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bpl-test pearu1 : test_cltree.py cltree.cpp ;
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bpl-test try : newtest.py m1.cpp m2.cpp ;
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bpl-test builtin_converters : test_builtin_converters.py test_builtin_converters.cpp ;

‎test/exception_translator.cpp‎

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#include <boost/python/module.hpp>
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#include <boost/python/exception_translator.hpp>
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struct error {};
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void translate(error const& e)
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{
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PyErr_SetString(PyExc_RuntimeError, "!!!error!!!");
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}
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void throw_error()
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{
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throw error();
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}
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BOOST_PYTHON_MODULE_INIT(exception_translator_ext)
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{
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using namespace boost::python;
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register_exception_translator<error>(&translate);
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module("exception_translator_ext")
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.def("throw_error", throw_error);
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}
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‎test/exception_translator.py‎

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'''
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>>> from exception_translator_ext import *
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>>> try:
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... throw_error();
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... except RuntimeError, x:
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... print x
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... else:
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... print 'Expected a RuntimeError!'
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!!!error!!!
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'''
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def run(args = None):
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import sys
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import doctest
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if args is not None:
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sys.argv = args
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return doctest.testmod(sys.modules.get(__name__))
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if __name__ == '__main__':
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print "running..."
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import sys
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sys.exit(run()[0])

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