Add numeric features management to Dataset

src/common/Discretization.cpp

@@ -0,0 +1,55 @@
+#include "Discretization.h"
+
+namespace platform {
+    // Idea from: https://www.codeproject.com/Articles/567242/AplusC-2b-2bplusObjectplusFactory
+    Discretization* Discretization::factory = nullptr;
+    Discretization* Discretization::instance()
+    {
+        //manages singleton
+        if (factory == nullptr)
+            factory = new Discretization();
+        return factory;
+    }
+    void Discretization::registerFactoryFunction(const std::string& name,
+        function<mdlp::Discretizer* (void)> classFactoryFunction)
+    {
+        // register the class factory function
+        functionRegistry[name] = classFactoryFunction;
+    }
+    std::shared_ptr<mdlp::Discretizer> Discretization::create(const std::string& name)
+    {
+        mdlp::Discretizer* instance = nullptr;
+
+        // find name in the registry and call factory method.
+        auto it = functionRegistry.find(name);
+        if (it != functionRegistry.end())
+            instance = it->second();
+        // wrap instance in a shared ptr and return
+        if (instance != nullptr)
+            return std::unique_ptr<mdlp::Discretizer>(instance);
+        else
+            throw std::runtime_error("Discretizer not found: " + name);
+    }
+    std::vector<std::string> Discretization::getNames()
+    {
+        std::vector<std::string> names;
+        transform(functionRegistry.begin(), functionRegistry.end(), back_inserter(names),
+            [](const pair<std::string, function<mdlp::Discretizer* (void)>>& pair) { return pair.first; });
+        return names;
+    }
+    std::string Discretization::toString()
+    {
+        std::string result = "";
+        std::string sep = "";
+        for (const auto& pair : functionRegistry) {
+            result += sep + pair.first;
+            sep = ", ";
+        }
+        return "{" + result + "}";
+    }
+    RegistrarDiscretization::RegistrarDiscretization(const std::string& name, function<mdlp::Discretizer* (void)> classFactoryFunction)
+    {
+        // register the class factory function 
+        Discretization::instance()->registerFactoryFunction(name, classFactoryFunction);
+    }
+}