gras: created element factory

1 files changed, 151 insertions, 0 deletions

diff --git a/include/gras/detail/factory.hpp b/include/gras/detail/factory.hpp
new file mode 100644
index 0000000..0487e76
--- /dev/null
+++ b/include/gras/detail/factory.hpp
@@ -0,0 +1,151 @@
+// Copyright (C) by Josh Blum. See LICENSE.txt for licensing information.
+
+#ifndef INCLUDED_GRAS_DETAIL_FACTORY_HPP
+#define INCLUDED_GRAS_DETAIL_FACTORY_HPP
+
+#include <PMC/Containers.hpp> //PMCList
+
+namespace gras
+{
+
+/***********************************************************************
+ * Factory entry base class
+ **********************************************************************/
+struct GRAS_API FactoryRegistryEntry
+{
+    FactoryRegistryEntry(void);
+    virtual ~FactoryRegistryEntry(void);
+    virtual Element *make(const PMCC &args) = 0;
+};
+
+/***********************************************************************
+ * Templated registration - 0 args
+ **********************************************************************/
+template <typename ReturnType>
+struct FactoryRegistryEntryImpl0 : FactoryRegistryEntry
+{
+    typedef ReturnType(*Fcn)(void);
+    FactoryRegistryEntryImpl0(Fcn fcn):_fcn(fcn){}
+    Element *make(const PMCC &)
+    {
+        return _fcn();
+    }
+    Fcn _fcn;
+};
+
+template <typename ReturnType>
+void Factory::register_make(const std::string &name, ReturnType(*fcn)(void))
+{
+    void *r = new FactoryRegistryEntryImpl0<ReturnType>(fcn);
+    Factory::_register_make(name, r);
+}
+
+/***********************************************************************
+ * Templated registration - 1 args
+ **********************************************************************/
+template <typename ReturnType, typename Arg0>
+struct FactoryRegistryEntryImpl1 : FactoryRegistryEntry
+{
+    typedef ReturnType(*Fcn)(const Arg0 &);
+    FactoryRegistryEntryImpl1(Fcn fcn):_fcn(fcn){}
+    Element *make(const PMCC &args)
+    {
+        const PMCList &a = args.as<PMCList>();
+        return _fcn(a[0].safe_as<Arg0>());
+    }
+    Fcn _fcn;
+};
+
+template <typename ReturnType, typename Arg0>
+void Factory::register_make(const std::string &name, ReturnType(*fcn)(const Arg0 &))
+{
+    void *r = new FactoryRegistryEntryImpl1<ReturnType, Arg0>(fcn);
+    Factory::_register_make(name, r);
+}
+
+/***********************************************************************
+ * Templated registration - 2 args
+ **********************************************************************/
+template <typename ReturnType, typename Arg0, typename Arg1>
+struct FactoryRegistryEntryImpl2 : FactoryRegistryEntry
+{
+    typedef ReturnType(*Fcn)(const Arg0 &, const Arg1 &);
+    FactoryRegistryEntryImpl2(Fcn fcn):_fcn(fcn){}
+    Element *make(const PMCC &args)
+    {
+        const PMCList &a = args.as<PMCList>();
+        return _fcn(a[0].safe_as<Arg0>(), a[1].safe_as<Arg1>());
+    }
+    Fcn _fcn;
+};
+
+template <typename ReturnType, typename Arg0, typename Arg1>
+void Factory::register_make(const std::string &name, ReturnType(*fcn)(const Arg0 &, const Arg1 &))
+{
+    void *r = new FactoryRegistryEntryImpl2<ReturnType, Arg0, Arg1>(fcn);
+    Factory::_register_make(name, r);
+}
+
+/***********************************************************************
+ * Templated registration - 3 args
+ **********************************************************************/
+template <typename ReturnType, typename Arg0, typename Arg1, typename Arg2>
+struct FactoryRegistryEntryImpl3 : FactoryRegistryEntry
+{
+    typedef ReturnType(*Fcn)(const Arg0 &, const Arg1 &, const Arg2 &);
+    FactoryRegistryEntryImpl3(Fcn fcn):_fcn(fcn){}
+    Element *make(const PMCC &args)
+    {
+        const PMCList &a = args.as<PMCList>();
+        return _fcn(a[0].safe_as<Arg0>(), a[1].safe_as<Arg1>(), a[2].safe_as<Arg2>());
+    }
+    Fcn _fcn;
+};
+
+template <typename ReturnType, typename Arg0, typename Arg1, typename Arg2>
+void Factory::register_make(const std::string &name, ReturnType(*fcn)(const Arg0 &, const Arg1 &, const Arg2 &))
+{
+    void *r = new FactoryRegistryEntryImpl3<ReturnType, Arg0, Arg1, Arg2>(fcn);
+    Factory::_register_make(name, r);
+}
+
+/***********************************************************************
+ * Templated make implementations
+ **********************************************************************/
+inline
+Element *Factory::make(const std::string &name)
+{
+    PMCList args(0);
+    return Factory::_make(name, PMC_M(args));
+}
+
+template <typename Arg0>
+Element *Factory::make(const std::string &name, const Arg0 &a0)
+{
+    PMCList args(1);
+    args[0] = PMC_M(a0);
+    return Factory::_make(name, PMC_M(args));
+}
+
+template <typename Arg0, typename Arg1>
+Element *Factory::make(const std::string &name, const Arg0 &a0, const Arg1 &a1)
+{
+    PMCList args(2);
+    args[0] = PMC_M(a0);
+    args[1] = PMC_M(a1);
+    return Factory::_make(name, PMC_M(args));
+}
+
+template <typename Arg0, typename Arg1, typename Arg2>
+Element *Factory::make(const std::string &name, const Arg0 &a0, const Arg1 &a1, const Arg2 &a2)
+{
+    PMCList args(3);
+    args[0] = PMC_M(a0);
+    args[1] = PMC_M(a1);
+    args[2] = PMC_M(a2);
+    return Factory::_make(name, PMC_M(args));
+}
+
+}
+
+#endif /*INCLUDED_GRAS_DETAIL_FACTORY_HPP*/