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Add arity registration for dynamic functions

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This commit is contained in:
Jason Turner 2009-06-05 16:12:21 +00:00
parent 5799d7f0ef
commit 37a36f783c
2 changed files with 12 additions and 14 deletions
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14
boxedcpp/proxy_functions.hpp
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@ -107,8 +107,8 @@ class Proxy_Function
class Dynamic_Proxy_Function : public Proxy_Function class Dynamic_Proxy_Function : public Proxy_Function
{ {
public: public:
Dynamic_Proxy_Function(const boost::function<Boxed_Value (const std::vector<Boxed_Value> &)> &t_f) Dynamic_Proxy_Function(const boost::function<Boxed_Value (const std::vector<Boxed_Value> &)> &t_f, int arity=-1)
: m_f(t_f) : m_f(t_f), m_arity(arity)
{ {
} }
@ -116,7 +116,12 @@ class Dynamic_Proxy_Function : public Proxy_Function
virtual Boxed_Value operator()(const std::vector<Boxed_Value> &params) virtual Boxed_Value operator()(const std::vector<Boxed_Value> &params)
{ {
return m_f(params); if (m_arity < 0 || params.size() == size_t(m_arity))
{
return m_f(params);
} else {
throw std::range_error("Incorrect number of parameters");
}
} }
virtual std::vector<Type_Info> get_param_types() virtual std::vector<Type_Info> get_param_types()
@ -126,6 +131,7 @@ class Dynamic_Proxy_Function : public Proxy_Function
private: private:
boost::function<Boxed_Value (const std::vector<Boxed_Value> &)> m_f; boost::function<Boxed_Value (const std::vector<Boxed_Value> &)> m_f;
int m_arity;
}; };
template<typename Func> template<typename Func>
@ -165,6 +171,8 @@ Boxed_Value dispatch(const std::vector<std::pair<const std::string, boost::share
return (*itr->second)(plist); return (*itr->second)(plist);
} catch (const std::bad_cast &) { } catch (const std::bad_cast &) {
//try again //try again
} catch (const std::range_error &) {
//invalid num params, try again
} }
} }

12
wesley/main.cpp
View File

@ -82,16 +82,6 @@ std::string concat_string(const std::string &s1, const std::string &s2) {
} }
const Boxed_Value add_two(BoxedCPP_System &ss, const std::vector<Boxed_Value> &vals) { const Boxed_Value add_two(BoxedCPP_System &ss, const std::vector<Boxed_Value> &vals) {
//We can check the arity if we want, or in this case just allow the dispatch
//to do it for us:
if (vals.size() != 2)
{
//I very much need to do a cleanup and provide a custom set of
//bad_cast and wrong_arity exceptions so they can be caught more
//cleanly
throw std::runtime_error("Wrong number of args");
}
return dispatch(ss.get_function("+"), vals); return dispatch(ss.get_function("+"), vals);
} }
@ -414,7 +404,7 @@ BoxedCPP_System build_eval_system() {
ss.register_function(boost::function<std::string (const std::string &, const std::string &)>(concat_string), "concat_string"); ss.register_function(boost::function<std::string (const std::string &, const std::string &)>(concat_string), "concat_string");
ss.register_function(boost::shared_ptr<Proxy_Function>( ss.register_function(boost::shared_ptr<Proxy_Function>(
new Dynamic_Proxy_Function(boost::bind(&add_two, boost::ref(ss), _1))), "add_two"); new Dynamic_Proxy_Function(boost::bind(&add_two, boost::ref(ss), _1), 2)), "add_two");
return ss; return ss;