removed attribute_generator and constraints_generator

source/core/object/restriction.cpp

@@ -8,7 +8,7 @@ restriction::restriction(std::string name)
 : name_(std::move(name)) {}
 
 std::string restriction::name() const {
-  return prefix() + name_;
+  return type_string() + name_;
 }
 
 const class attribute* restriction::attribute() const {
@@ -55,21 +55,21 @@ const std::string& restriction::ref_column_name() const {
 }
 
 std::ostream & operator<<(std::ostream &os, const class restriction &c) {
-  os << "constraint " << c.name() << " for column " << c.column_name();
+  os << "constraint " << c.type_string() << " for column " << c.column_name();
   return os;
 }
 
-std::string restriction::prefix() const {
+std::string restriction::type_string() const {
     if (utils::is_constraint_set(options_, utils::constraints::PrimaryKey)) {
-        return "PK_";
+        return "PrimaryKey";
     }
     if (utils::is_constraint_set(options_, utils::constraints::ForeignKey)) {
-        return "FK_";
+        return "ForeignKey";
     }
     if (utils::is_constraint_set(options_, utils::constraints::Unique)) {
-        return "UK_";
+        return "Unique";
     }
-    return "";
+    return "Unknown";
 }
 
 // constraint_builder & constraint_builder::constraint(std::string name) {