Reduce operator boilerplate

Add notion of constructable operators. Implement vname directly on _PlanOperation, freeing operations from having to declare it.
hyrise · Mar 13, 2013 · 6576e8d · 6576e8d
1 parent c32cc90
commit 6576e8d
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Showing 3 changed files with 27 additions and 3 deletions.
diff --git a/src/lib/access/PlanOperation.cpp b/src/lib/access/PlanOperation.cpp
@@ -287,3 +287,7 @@ const std::string& _PlanOperation::planOperationName() const {
 void _PlanOperation::setPlanOperationName(const std::string& name) {
   _planOperationName = name;
 }
+
+const std::string _PlanOperation::vname() {
+  return planOperationName();
+}
diff --git a/src/lib/access/PlanOperation.h b/src/lib/access/PlanOperation.h
@@ -131,6 +131,7 @@ class _PlanOperation : public OutputTask {
   void setPlanOperationName(const std::string& name);
 
   virtual void operator()() noexcept;
+  virtual const std::string vname();
   const _PlanOperation *execute();
 };
 

diff --git a/src/lib/access/QueryParser.h b/src/lib/access/QueryParser.h
@@ -28,14 +28,27 @@ struct AbstractQueryParserFactory {
   virtual ~AbstractQueryParserFactory() {}
 };
 
+struct parse_construct {};
+struct default_construct {};
+
+template <typename T, typename parse_construction>
+struct QueryParserFactory;
+
 template<typename T>
-struct QueryParserFactory : public AbstractQueryParserFactory {
+struct QueryParserFactory<T, parse_construct> : public AbstractQueryParserFactory {
 
   virtual std::shared_ptr<_PlanOperation> parse(Json::Value data) {
     return T::parse(data);
   }
 };
 
+template<typename T>
+struct QueryParserFactory<T, default_construct> : public AbstractQueryParserFactory {
+  virtual std::shared_ptr<_PlanOperation> parse(Json::Value data) {
+    return std::make_shared<T>();
+  }
+};
+
 /*
  * The Query Parser parses a given Json Value to create a plan operation
  *
@@ -76,16 +89,22 @@ class QueryParser {
 
   template<typename T>
   static bool registerPlanOperation() {
-    QueryParser::instance()._factory[T::name()] = new QueryParserFactory<T>();
+    QueryParser::instance()._factory[T::name()] = new QueryParserFactory<T, parse_construct>();
     return true;
   }
 
   template<typename T>
   static bool registerPlanOperation(const std::string& name) {
-    QueryParser::instance()._factory[name] = new QueryParserFactory<T>();
+    QueryParser::instance()._factory[name] = new QueryParserFactory<T, parse_construct>();
     return true;
   }
 
+  template<typename T>
+  static bool registerTrivialPlanOperation(const std::string& name) {
+    QueryParser::instance()._factory[name] = new QueryParserFactory<T, default_construct>();
+    return true;
+  }
+
   std::shared_ptr<_PlanOperation> parse(std::string name, Json::Value d);
 
   static QueryParser &instance();