Start working on type code

03/type.cpp

@@ -0,0 +1,25 @@
+#include "type.hpp"
+#include <sstream>
+#include <algorithm>
+
+std::string type_mgr::new_type_name() {
+    std::ostringstream oss;
+    int temp = last_id++;
+
+    do {
+        oss << (char) ('a' + (temp % 26));
+        temp /= 26;
+    } while(temp);
+    std::string str = oss.str();
+
+    std::reverse(str.begin(), str.end());
+    return str;
+};
+
+type_ptr type_mgr::new_type() {
+    return type_ptr(new type_var(new_type_name()));
+}
+
+type_ptr type_mgr::new_arrow_type() {
+    return type_ptr(new type_arr(new_type(), new_type()));
+}