From 0e897b412aba6ae7b37207a767800b2e43ef66af Mon Sep 17 00:00:00 2001
From: Marko Budiselic <mbudiselicbuda@gmail.com>
Date: Thu, 25 Feb 2016 23:49:35 +0100
Subject: [PATCH] small code refactor

---
 query_engine/code_generator.hpp               | 21 +++++++++---
 query_engine/traverser/code_traverser.hpp     | 34 +++++++++++++++++++
 query_engine/traverser/query_traverser.hpp    | 27 ---------------
 query_engine/traverser/read_traverser.hpp     |  9 +++++
 query_engine/traverser/update_traverser.hpp   |  7 ++++
 ...eate_traverser.hpp => write_traverser.hpp} |  9 ++---
 6 files changed, 68 insertions(+), 39 deletions(-)
 create mode 100644 query_engine/traverser/code_traverser.hpp
 delete mode 100644 query_engine/traverser/query_traverser.hpp
 create mode 100644 query_engine/traverser/read_traverser.hpp
 create mode 100644 query_engine/traverser/update_traverser.hpp
 rename query_engine/traverser/{create_traverser.hpp => write_traverser.hpp} (88%)

diff --git a/query_engine/code_generator.hpp b/query_engine/code_generator.hpp
index d196e7b8c..cc4448590 100644
--- a/query_engine/code_generator.hpp
+++ b/query_engine/code_generator.hpp
@@ -1,9 +1,11 @@
 #pragma once
 
+#include "cypher/ast/ast.hpp"
+#include "cypher/compiler.hpp"
 #include "utils/string/file.hpp"
 #include "template_engine/engine.hpp"
 #include "config/config.hpp"
-#include "traverser/query_traverser.hpp"
+#include "traverser/code_traverser.hpp"
 
 using std::string;
 
@@ -15,23 +17,32 @@ public:
                       const uint64_t stripped_hash,
                       const std::string& path)
     {
+        // get paths
         string template_path = CONFIG(config::TEMPLATE_CPU_CPP_PATH);
         string template_file = utils::read_file(template_path.c_str());
-        traverser.build_tree(query);
-        string code = traverser.traverse();
+
+        // traversing
+        auto tree = compiler.syntax_tree(query);
+        code_traverser.reset();
+        tree.root->accept(code_traverser);
+
+        // save the code
         string generated = template_engine.render(
             template_file,
             {
                 {"class_name", "CodeCPU"},
                 {"stripped_hash", std::to_string(stripped_hash)},
                 {"query", query},
-                {"code", code},
+                {"code", code_traverser.code},
                 {"return_type", "int"}
             }
         );
         utils::write_file(generated, path);
     }
+
 private:
     template_engine::TemplateEngine template_engine;  
-    QueryTraverser traverser;
+    ast::Ast tree;
+    cypher::Compiler compiler;
+    CodeTraverser code_traverser;
 };
diff --git a/query_engine/traverser/code_traverser.hpp b/query_engine/traverser/code_traverser.hpp
new file mode 100644
index 000000000..b6fa175ac
--- /dev/null
+++ b/query_engine/traverser/code_traverser.hpp
@@ -0,0 +1,34 @@
+#pragma once
+
+#include <string>
+
+#include "cypher/visitor/traverser.hpp"
+#include "cypher/ast/queries.hpp"
+#include "write_traverser.hpp"
+#include "read_traverser.hpp"
+
+class CodeTraverser : public Traverser
+{
+public:
+
+    std::string code;
+
+    void reset()
+    {
+        code = "";
+    }
+
+    void visit(ast::WriteQuery& write_query) override
+    {
+        auto write_traverser = WriteTraverser();
+        write_query.accept(write_traverser);
+        code = write_traverser.code;
+    }
+
+    void visit(ast::ReadQuery& read_query) override
+    {
+        auto read_traverser = ReadTraverser();
+        read_query.accept(read_traverser);
+        code = read_traverser.code;
+    }
+};
diff --git a/query_engine/traverser/query_traverser.hpp b/query_engine/traverser/query_traverser.hpp
deleted file mode 100644
index 5eca9513f..000000000
--- a/query_engine/traverser/query_traverser.hpp
+++ /dev/null
@@ -1,27 +0,0 @@
-#pragma once
-
-#include "cypher/ast/ast.hpp"
-#include "cypher/compiler.hpp"
-#include "create_traverser.hpp"
-
-class QueryTraverser
-{
-public:
-    QueryTraverser() = default;
-
-    void build_tree(const std::string& query)
-    {
-        tree = compiler.syntax_tree(query);
-    }
-
-    std::string traverse()
-    {
-        tree.root->accept(traverser);
-        return traverser.code;
-    }
-
-private:
-    ast::Ast tree;
-    cypher::Compiler compiler;
-    CreateTraverser traverser;
-};
diff --git a/query_engine/traverser/read_traverser.hpp b/query_engine/traverser/read_traverser.hpp
new file mode 100644
index 000000000..ad42bf146
--- /dev/null
+++ b/query_engine/traverser/read_traverser.hpp
@@ -0,0 +1,9 @@
+#pragma once
+
+#include "cypher/visitor/traverser.hpp"
+
+class ReadTraverser : public Traverser
+{
+public:
+    std::string code;
+};
diff --git a/query_engine/traverser/update_traverser.hpp b/query_engine/traverser/update_traverser.hpp
new file mode 100644
index 000000000..914076bdf
--- /dev/null
+++ b/query_engine/traverser/update_traverser.hpp
@@ -0,0 +1,7 @@
+#pragma once
+
+#include "cypher/visitor/traverser.hpp"
+
+class UpdateTraverser : public Traverser
+{
+};
diff --git a/query_engine/traverser/create_traverser.hpp b/query_engine/traverser/write_traverser.hpp
similarity index 88%
rename from query_engine/traverser/create_traverser.hpp
rename to query_engine/traverser/write_traverser.hpp
index f14128b39..ad97aba4c 100644
--- a/query_engine/traverser/create_traverser.hpp
+++ b/query_engine/traverser/write_traverser.hpp
@@ -7,13 +7,10 @@
 #include "cypher/visitor/traverser.hpp"
 #include "query_engine/util.hpp"
 
-using std::cout;
-using std::endl;
 
-class CreateTraverser : public Traverser
+class WriteTraverser : public Traverser
 {
 private:
-    std::string key;
     uint32_t index{0};
 
 public:
@@ -29,9 +26,7 @@ public:
 
     void visit(ast::Property& property) override
     {
-        key = property.idn->name;
-
-        Traverser::visit(property);
+        auto key = property.idn->name;
 
         code += line("vertex_accessor.property(");
         code += line("\t\"" + key + "\", args[" + std::to_string(index) + "]");