A lot of work on query_engine. Still in progress!

src/cypher/ast/accessor.hpp

@@ -16,6 +16,12 @@ struct Accessor : public ValueExpr<Accessor>
 
     Identifier* entity;
     Identifier* prop;
+
+    bool has_entity() const { return entity != nullptr; }
+    bool has_prop() const { return prop != nullptr; }
+
+    std::string entity_name() const { return entity->name; }
+    std::string entity_prop() const { return prop->name; }
 };
 
 }

src/cypher/ast/ast_visitor.hpp

@@ -19,6 +19,7 @@ struct Boolean;
 struct Float;
 struct Integer;
 struct String;
+struct Long;
 
 // operators
 struct And;
@@ -36,7 +37,7 @@ struct Slash;
 struct Rem;
 
 struct RelationshipSpecs;
-struct RelationshipList;
+struct RelationshipTypeList;
 struct Relationship;
 
 struct Node;
@@ -74,18 +75,15 @@ struct WithQuery;
 struct InternalIdExpr;
 
 struct AstVisitor
-    : public Visitor<Accessor, Boolean, Float, Identifier, Alias, Integer,
-                     String, Property, And, Or, Lt, Gt, Ge, Le, Eq, Ne, Plus,
-                     Minus, Star, Slash, Rem, PropertyList, RelationshipList,
-                     Relationship, Node, RelationshipSpecs, LabelList,
-                     ReturnList, Pattern, PatternExpr, PatternList, Match,
-                     ReadQuery, Start, Where, WriteQuery, Create, Return,
-                     Distinct, Delete, DeleteQuery, UpdateQuery, Set, SetKey,
-                     ReadWriteQuery, IdentifierList,
-                     WithList, WithClause, WithQuery,
-                     InternalIdExpr,
-                     SetValue, SetElement, SetList>
+    : public Visitor<
+          Accessor, Boolean, Float, Identifier, Alias, Integer, String,
+          Property, And, Or, Lt, Gt, Ge, Le, Eq, Ne, Plus, Minus, Star, Slash,
+          Rem, PropertyList, RelationshipTypeList, Relationship, Node,
+          RelationshipSpecs, LabelList, ReturnList, Pattern, PatternExpr,
+          PatternList, Match, ReadQuery, Start, Where, WriteQuery, Create,
+          Return, Distinct, Delete, DeleteQuery, UpdateQuery, Set, SetKey,
+          ReadWriteQuery, IdentifierList, WithList, WithClause, WithQuery, Long,
+          InternalIdExpr, SetValue, SetElement, SetList>
 {
 };
-
 }

src/cypher/ast/list.hpp

@@ -13,6 +13,9 @@ struct List : public AstNode<Derived>
 
     T* value;
     Derived* next;
+
+    bool has_value() const { return value != nullptr; }
+    bool has_next() const { return next != nullptr; }
 };
 
 }

src/cypher/ast/node.hpp

@@ -19,6 +19,11 @@ struct Node : public AstNode<Node>
     Identifier* idn;
     LabelList* labels;
     PropertyList* props;
+
+    bool has_identifier() const
+    {
+        return idn != nullptr;
+    }
 };
 
 }

src/cypher/ast/pattern.hpp

@@ -1,25 +1,29 @@
 #pragma once
 
 #include "ast_node.hpp"
-#include "relationship.hpp"
 #include "node.hpp"
+#include "relationship.hpp"
 
 namespace ast
 {
-
 struct Pattern : public AstNode<Pattern>
 {
-    Pattern(Node* node, Relationship* relationship, Pattern* next)
-        : node(node), relationship(relationship), next(next) {}
+    Pattern(Node *node, Relationship *relationship, Pattern *next)
+        : node(node), relationship(relationship), next(next)
+    {
+    }
 
-    Node* node;
-    Relationship* relationship;
-    Pattern* next;
+    Node *node;
+    Relationship *relationship;
+    Pattern *next;
+
+    bool has_node() const { return node != nullptr; }
+    bool has_relationship() const { return relationship != nullptr; }
+    bool has_next() const { return next != nullptr; }
 };
 
 struct PatternList : public List<Pattern, PatternList>
 {
     using List::List;
 };
-
 }

src/cypher/ast/property.hpp

@@ -14,6 +14,11 @@ struct Property : public AstNode<Property>
 
     Identifier* idn;
     Expr* value;
+
+    bool has_name() const { return idn != nullptr; }
+    bool has_value() const { return value != nullptr; }
+
+    std::string name() const { return idn->name; }
 };
 
 struct PropertyList : public List<Property, PropertyList>

src/cypher/ast/relationship.hpp

@@ -1,35 +1,56 @@
 #pragma once
 
-#include "list.hpp"
 #include "identifier.hpp"
+#include "list.hpp"
 
 namespace ast
 {
 
-struct RelationshipList : public List<Identifier, RelationshipList>
+struct RelationshipTypeList : public List<Identifier, RelationshipTypeList>
 {
     using List::List;
 };
 
 struct RelationshipSpecs : public AstNode<RelationshipSpecs>
 {
-    RelationshipSpecs(Identifier* idn, RelationshipList* types, PropertyList* props)
-        : idn(idn), types(types), props(props) {}
+    RelationshipSpecs(Identifier *idn, RelationshipTypeList *types,
+                      PropertyList *props)
+        : idn(idn), types(types), props(props)
+    {
+    }
 
-    Identifier* idn;
-    RelationshipList* types;
-    PropertyList* props;
+    Identifier *idn;
+    RelationshipTypeList *types;
+    PropertyList *props;
+
+    bool has_identifier() const { return idn != nullptr; }
+
+    std::string name() const { return idn->name; }
 };
 
 struct Relationship : public AstNode<Relationship>
 {
-    enum Direction { Left, Right, Both };
+    enum Direction
+    {
+        Left,
+        Right,
+        Both
+    };
 
-    Relationship(RelationshipSpecs* specs, Direction direction)
-        : specs(specs), direction(direction) {}
+    Relationship(RelationshipSpecs *specs, Direction direction)
+        : specs(specs), direction(direction)
+    {
+    }
 
-    RelationshipSpecs* specs;
+    RelationshipSpecs *specs;
     Direction direction;
-};
 
+    bool has_relationship_specs() const { return specs != nullptr; }
+    bool has_name() const
+    {
+        return has_relationship_specs() && specs->has_identifier();
+    }
+
+    std::string name() const { return specs->name(); }
+};
 }

src/cypher/ast/set.hpp

@@ -31,6 +31,8 @@ struct SetValue : public AstNode<SetValue>
         : value(value) {}
 
     Expr* value;
+
+    bool has_value() const { return value != nullptr; }
 };
 
 struct SetElement : public AstNode<SetElement>
@@ -40,6 +42,9 @@ struct SetElement : public AstNode<SetElement>
 
     Accessor* accessor;
     SetValue* set_value;
+
+    bool has_accessor() const { return accessor != nullptr; }
+    bool has_value() const { return set_value != nullptr; }
 };
 
 struct SetList : public List<SetElement, SetList>

src/cypher/ast/start.hpp

@@ -3,8 +3,6 @@
 #include "ast_node.hpp"
 #include "queries.hpp"
 
-// LEGACY TODO remove from here
-
 namespace ast
 {
 

src/cypher/ast/values.hpp

@@ -39,15 +39,23 @@ struct String : public LeafExpr<std::string, String>
 
 struct InternalIdExpr : public Expr
 {
-    InternalIdExpr(Identifier *identifier, Integer *value)
-        : identifier(identifier), value(value)
+    InternalIdExpr(Identifier *entity, Long *id)
+        : entity(entity), id(id)
     {
     }
 
-    Identifier *identifier;
-    Integer *value;
+    Identifier *entity;
+    Long *id;
 
     virtual void accept(AstVisitor &visitor) { visitor.visit(*this); }
+
+    bool has_entity() const { return entity != nullptr; }
+    bool has_id() const { return id != nullptr; }
+
+    std::string entity_name() const { return entity->name; }
+    int64_t entity_id() const { return id->value; }
+
+
 };
 
 }

src/cypher/cypher.y

@@ -264,7 +264,7 @@ rel_idn(R) ::= . {
     R = nullptr;
 }
 
-%type rel_type {ast::RelationshipList*}
+%type rel_type {ast::RelationshipTypeList*}
 
 rel_type(L) ::= COLON rel_list(R). {
     L = R;
@@ -274,14 +274,14 @@ rel_type(L) ::= . {
     L = nullptr;
 }
 
-%type rel_list {ast::RelationshipList*}
+%type rel_list {ast::RelationshipTypeList*}
 
 rel_list(L) ::= idn(I) PIPE rel_list(R). {
-    L = ast->create<ast::RelationshipList>(I, R);
+    L = ast->create<ast::RelationshipTypeList>(I, R);
 }
 
 rel_list(L) ::= idn(I). {
-    L = ast->create<ast::RelationshipList>(I, nullptr);
+    L = ast->create<ast::RelationshipTypeList>(I, nullptr);
 }
 
 %type node {ast::Node*}
@@ -444,9 +444,9 @@ value_expr(E) ::= idn(I) DOT idn(P). {
     E = ast->create<ast::Accessor>(I, P);
 }
 
-value_expr(E) ::= ID LP idn(I) RP EQ INT(V). {
-    auto value = std::stoi(V->value);
-    E = ast->create<ast::InternalIdExpr>(I, ast->create<ast::Integer>(value));
+value_expr(E) ::= ID LP idn(I) RP EQ LONG(V). {
+    auto value = std::stol(V->value);
+    E = ast->create<ast::InternalIdExpr>(I, ast->create<ast::Long>(value));
 }
 
 %type idn {ast::Identifier*}
@@ -469,9 +469,9 @@ identifier_list(L) ::= idn(I). {
 
 // ----
 
-value_expr(E) ::= INT(V). {
-    auto value = std::stoi(V->value);
-    E = ast->create<ast::Integer>(value);
+value_expr(E) ::= LONG(V). {
+    auto value = std::stol(V->value);
+    E = ast->create<ast::Long>(value);
 }
 
 value_expr(E) ::= FLOAT(V). {

src/cypher/debug/tree_print.hpp

@@ -184,6 +184,12 @@ public:
         entry << "Integer " << integer.value;
     }
 
+    void visit(ast::Long& ast_long) override
+    {
+        auto entry = printer.advance();
+        entry << "Long " << ast_long.value;
+    }
+
     // void visit(ast::ULong& ulong) override
     // {
     //     auto entry = printer.advance();
@@ -292,9 +298,9 @@ public:
         Traverser::visit(prop_list);
     }
 
-    void visit(ast::RelationshipList& rel_list) override
+    void visit(ast::RelationshipTypeList& rel_list) override
     {
-        auto entry = printer.advance("Relationship List");
+        auto entry = printer.advance("Relationship Type List");
         Traverser::visit(rel_list);
     }
 

src/cypher/tokenizer/cypher_lexer.hpp

@@ -65,7 +65,7 @@ public:
         rule("\\\"(.*?)\\\"", TK_STR);
 
         // number
-        rule("\\d+", TK_INT);
+        rule("\\d+", TK_LONG);
         rule("\\d*[.]?\\d+", TK_FLOAT);
 
         // identifier

src/cypher/visitor/traverser.hpp

@@ -166,7 +166,7 @@ public:
         accept(pattern_list.next);
     }
 
-    void visit(ast::RelationshipList& rel_list) override
+    void visit(ast::RelationshipTypeList& rel_list) override
     {
         accept(rel_list.value);
         accept(rel_list.next);
@@ -278,8 +278,8 @@ public:
 
     void visit(ast::InternalIdExpr& internal_id) override
     {
-        accept(internal_id.identifier);
-        accept(internal_id.value);
+        accept(internal_id.entity);
+        accept(internal_id.id);
     }
 
 protected:

src/query_engine/code_compiler.hpp

@@ -2,7 +2,7 @@
 
 #include <string>
 
-#include "exceptions/query_engine_exception.hpp"
+#include "exceptions/exceptions.hpp"
 #include "utils/string/join.hpp"
 
 // TODO:
@@ -32,11 +32,14 @@ public:
 
         // if compilation has failed throw exception
         if (compile_status == -1) {
-            throw QueryEngineException("Code compilation error");
+            throw QueryEngineException("Code compilation error. Generated code "
+                                       "is not compilable or compilation "
+                                       "settings are wrong");
         }
 
         // TODO: use logger
         std::cout << fmt::format("SUCCESS: Query Code Compilation: {} -> {}",
-                                 in_file, out_file) << std::endl;
+                                 in_file, out_file)
+                  << std::endl;
     }
 };

src/query_engine/code_generator.hpp

@@ -3,10 +3,10 @@
 #include "config/config.hpp"
 #include "cypher/ast/ast.hpp"
 #include "cypher/compiler.hpp"
+#include "query_engine/exceptions/exceptions.hpp"
 #include "template_engine/engine.hpp"
-#include "traverser/code_traverser.hpp"
+#include "traverser/cpp_traverser.hpp"
 #include "utils/string/file.hpp"
-#include "query_engine/exceptions/query_engine_exception.hpp"
 
 // TODO:
 //     * logger
@@ -20,6 +20,11 @@ public:
     void generate_cpp(const std::string &query, const uint64_t stripped_hash,
                       const std::string &path)
     {
+        // TODO: optimize initialize only once -> be careful that object has
+        // a state
+        // TODO: multithread test
+        CppTraverser cpp_traverser;
+
         // get paths
         string template_path = CONFIG(config::TEMPLATE_CPU_CPP_PATH);
         string template_file = utils::read_file(template_path.c_str());
@@ -32,13 +37,14 @@ public:
             throw QueryEngineException("Syntax tree generation error");
         }
 
-        code_traverser.reset();
+        cpp_traverser.reset();
 
         // code generation
         try {
-            tree.root->accept(code_traverser);
+            tree.root->accept(cpp_traverser);
+        } catch (const SemanticException &e) {
+            throw e;
         } catch (const std::exception &e) {
-            // TODO: extract more information
             throw QueryEngineException("Code generation error");
         }
 
@@ -47,7 +53,7 @@ public:
             template_file, {{"class_name", "CodeCPU"},
                             {"stripped_hash", std::to_string(stripped_hash)},
                             {"query", query},
-                            {"code", code_traverser.code}});
+                            {"code", cpp_traverser.code}});
 
         // TODO: use logger, ifndef
         std::cout << generated << std::endl;
@@ -59,5 +65,4 @@ private:
     template_engine::TemplateEngine template_engine;
     ast::Ast tree;
     cypher::Compiler compiler;
-    CodeTraverser code_traverser;
 };

src/query_engine/code_generator/clause_action.hpp

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <cstdint>
+
+enum class ClauseAction : uint32_t
+{
+    Undefined,
+    CreateNode,
+    MatchNode,
+    UpdateNode,
+    DeleteNode,
+    CreateRelationship,
+    MatchRelationship,
+    UpdateRelationship,
+    DeleteRelationship,
+    ReturnNode,
+    ReturnRelationship,
+    ReturnPack,
+    ReturnProjection
+};

src/query_engine/code_generator/cpp_generator.hpp

@@ -0,0 +1,82 @@
+#pragma once
+
+#include <vector>
+
+#include "query_engine/code_generator/cypher_state.hpp"
+#include "query_engine/code_generator/query_action.hpp"
+#include "query_engine/exceptions/exceptions.hpp"
+
+class CppGenerator
+{
+public:
+    // !! multithread problem
+    // two threads shouldn't use this implementation at the same time
+    // !! TODO: REFACTOR
+
+    CppGenerator() : unprocessed_index(0), processed_index(0) { setup(); }
+
+    void state(CypherState state) { _cypher_state = state; }
+
+    CypherState state() { return _cypher_state; }
+
+    std::string generate()
+    {
+        std::string code = "";
+
+        for (uint64_t i = processed_index; i < unprocessed_index; ++i) {
+            auto &action = actions.at(i);
+            auto query_action = action.first;
+            if (action_functions.find(query_action) == action_functions.end())
+                throw CppGeneratorException(
+                    "Query Action Function is not defined");
+            auto &action_data = action.second;
+            code += action_functions[query_action](_cypher_data, action_data);
+            ++processed_index;
+        }
+
+        return code;
+    }
+
+    QueryActionData &add_action(const QueryAction &query_action)
+    {
+        unprocessed_index++;
+        actions.push_back(std::make_pair(query_action, QueryActionData()));
+        return action_data();
+    }
+
+    QueryActionData &action_data() { return actions.back().second; }
+
+    CypherStateData &cypher_data() { return _cypher_data; }
+
+    void clear()
+    {
+        processed_index = 0;
+        unprocessed_index = 0;
+        actions.clear();
+    }
+
+private:
+    // TODO: setup function is going to be called every time
+    // when object of this class is constructed (optimize this)
+    void setup()
+    {
+        action_functions[QueryAction::TransactionBegin] =
+            transaction_begin_action;
+        action_functions[QueryAction::Create] = create_query_action;
+        action_functions[QueryAction::Match] = match_query_action;
+        action_functions[QueryAction::Return] = return_query_action;
+        action_functions[QueryAction::Set] = set_query_action;
+        action_functions[QueryAction::TransactionCommit] =
+            transaction_commit_action;
+    }
+
+    uint64_t unprocessed_index;
+    uint64_t processed_index;
+    std::vector<std::pair<QueryAction, QueryActionData>> actions;
+    std::map<QueryAction,
+             std::function<std::string(CypherStateData &cypher_data,
+                                       QueryActionData &action_data)>>
+        action_functions;
+    CypherState _cypher_state;
+    CypherStateData _cypher_data;
+};

src/query_engine/code_generator/cypher_state.hpp

@@ -0,0 +1,86 @@
+#pragma once
+
+#include <cstdint>
+#include <map>
+#include <string>
+
+// main states that are used while ast is traversed
+// in order to generate ActionSequence
+enum class CypherState : uint8_t
+{
+    Undefined,
+    Match,
+    Where,
+    Create,
+    Set,
+    Return,
+    Delete
+};
+
+enum class EntityStatus : uint8_t
+{
+    NotFound,
+    Matched,
+    Created
+};
+
+enum class EntityType : uint8_t
+{
+    NotFound,
+    Node,
+    Relationship
+};
+
+class CypherStateData
+{
+private:
+    std::map<std::string, EntityStatus> entity_status;
+    std::map<std::string, EntityType> entity_type;
+    // TODO: container that keeps track about c++ variable names
+
+public:
+    bool exist(const std::string& name) const
+    {
+        return entity_status.find(name) != entity_status.end();
+    }
+
+    EntityStatus status(const std::string &name)
+    {
+        if (entity_status.find(name) == entity_status.end())
+            return EntityStatus::NotFound;
+
+        return entity_status.at(name);
+    }
+
+    EntityType type(const std::string &name)
+    {
+        if (entity_type.find(name) == entity_type.end())
+            return EntityType::NotFound;
+
+        return entity_type.at(name);
+    }
+
+    void node_matched(const std::string &name)
+    {
+        entity_type[name] = EntityType::Node;
+        entity_status[name] = EntityStatus::Matched;
+    }
+
+    void node_created(const std::string &name)
+    {
+        entity_type[name] = EntityType::Node;
+        entity_status[name] = EntityStatus::Created;
+    }
+
+    void relationship_matched(const std::string &name)
+    {
+        entity_type[name] = EntityType::Relationship;
+        entity_status[name] = EntityStatus::Matched;
+    }
+
+    void relationship_created(const std::string &name)
+    {
+        entity_type[name] = EntityType::Relationship;
+        entity_status[name] = EntityStatus::Created;
+    }
+};

src/query_engine/code_generator/entity_search.hpp

@@ -116,6 +116,9 @@ public:
     entity_search::search_cost_t::SearchPlace
     min(const std::string &entity) const
     {
+        if (_search_costs.find(entity) == _search_costs.end())
+            return entity_search::search_cost_t::SearchPlace::main_storage;
+
         return _search_costs.at(entity).min();
     }
 

src/query_engine/code_generator/query_action.hpp

@@ -0,0 +1,110 @@
+#pragma once
+
+#include <iostream>
+#include <map>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "query_engine/code_generator/cypher_state.hpp"
+#include "query_engine/code_generator/query_action_data.hpp"
+#include "query_engine/traverser/code.hpp"
+
+using ParameterIndexKey::Type::InternalId;
+
+// any entity (node or relationship) inside cypher query has an action
+// that is associated with that entity
+enum class QueryAction : uint32_t
+{
+    TransactionBegin,
+    Create,
+    Match,
+    Set,
+    Return,
+    TransactionCommit
+};
+
+auto transaction_begin_action = [](CypherStateData &,
+                                   const QueryActionData &) -> std::string {
+    return LINE(code::transaction_begin);
+};
+
+auto create_query_action =
+    [](CypherStateData &cypher_data,
+       const QueryActionData &action_data) -> std::string {
+
+    std::string code = "";
+
+    for (auto const &kv : action_data.actions) {
+
+        if (kv.second == ClauseAction::CreateRelationship) {
+            auto name = kv.first;
+            code += LINE(fmt::format(code::create_edge, name));
+            cypher_data.relationship_created(name);
+        }
+    }
+
+    return code;
+};
+
+auto match_query_action =
+    [](CypherStateData &cypher_data,
+       const QueryActionData &action_data) -> std::string {
+
+    std::string code = "";
+
+    for (auto const &kv : action_data.actions) {
+
+        if (kv.second == ClauseAction::MatchNode) {
+            auto name = kv.first;
+            if (cypher_data.type(name) == EntityType::Node &&
+                cypher_data.status(name) == EntityStatus::Matched)
+                continue;
+        }
+
+        // find node
+        if (kv.second == ClauseAction::MatchNode) {
+            auto name = kv.first;
+            auto place = action_data.csm.min(kv.first);
+            if (place == entity_search::search_internal_id) {
+                auto index = action_data.parameter_index.at(
+                    ParameterIndexKey(InternalId, name));
+                code +=
+                    LINE(fmt::format(code::match_vertex_by_id, name, index));
+                cypher_data.node_matched(name);
+            }
+        }
+    }
+
+    return code;
+};
+
+auto set_query_action =
+    [](CypherStateData &cypher_data,
+       const QueryActionData &action_data) -> std::string {
+
+    std::string code = "";
+
+    for (auto const &kv : action_data.actions) {
+        auto name = kv.first;
+        if (kv.second == ClauseAction::UpdateNode &&
+            cypher_data.status(name) == EntityStatus::Matched &&
+            cypher_data.type(name) == EntityType::Node) {
+            auto entity_data = action_data.get_entity_property(name);
+            for (auto &property : entity_data.properties) {
+                auto index = action_data.parameter_index.at(ParameterIndexKey(name, property));
+               code += LINE(fmt::format(code::update_property, name, property, index)); 
+            }
+        }
+    }
+
+    return code;
+};
+
+auto return_query_action = [](
+    CypherStateData &, const QueryActionData &) -> std::string { return ""; };
+
+auto transaction_commit_action = [](CypherStateData &,
+                                    const QueryActionData &) -> std::string {
+    return LINE(code::transaction_commit) + LINE(code::return_empty_result);
+};

src/query_engine/code_generator/query_action_data.hpp

@@ -0,0 +1,144 @@
+#pragma once
+
+#include <iostream>
+#include <map>
+#include <vector>
+
+#include "query_engine/exceptions/exceptions.hpp"
+#include "query_engine/code_generator/clause_action.hpp"
+#include "query_engine/code_generator/entity_search.hpp"
+#include "storage/model/properties/all.hpp"
+#include "utils/assert.hpp"
+#include "utils/underlying_cast.hpp"
+
+// used for storing data related to an entity (node or relationship)
+// data can be:
+//     * tags: labels or type
+//     * props: property name, property value
+struct EntityData
+{
+    std::vector<std::string> tags;
+    std::vector<std::string> properties;
+
+    void add_tag(const std::string &tag) { tags.push_back(tag); }
+    void add_property(const std::string &property)
+    {
+        properties.push_back(property);
+    }
+};
+
+// used for storing indices of parameters (parameters are stripped before
+// compiling process into the array), so somehow the compiler has to know
+// how to find appropriate parameter during the compile process
+//
+// parameter index key can be related to:
+//     * internal_id and entity_name, e.g.:
+//     ID(n)=35445 -> ID(n)=2 -> index[PropertyIndexKey(Type::InternalId, n)] =
+//     2
+//     * entity_name and entity_property, e.g.:
+//     n.name = "test" -> n.name = 3 -> index[PropertyIndexKey(entity_name,
+//     entity_property)] = 3
+struct ParameterIndexKey
+{
+    enum class Type : uint8_t
+    {
+        InternalId,
+        Projection
+    };
+
+    ParameterIndexKey(Type type, const std::string &entity_name)
+        : type(type), entity_name(entity_name)
+    {
+    }
+
+    ParameterIndexKey(const std::string &entity_name,
+                      const std::string &entity_property)
+        : type(Type::Projection), entity_name(entity_name),
+          entity_property(entity_property)
+    {
+    }
+
+    const Type type;
+    const std::string entity_name;
+    const std::string entity_property;
+
+    bool operator<(const ParameterIndexKey &rhs) const
+    {
+        runtime_assert(type == rhs.type,
+                       "ParameterIndexKey types should be the same");
+
+        if (type == Type::InternalId) return entity_name < rhs.entity_name;
+
+        if (entity_name == rhs.entity_name)
+            return entity_property < rhs.entity_property;
+
+        return entity_name < rhs.entity_name;
+    }
+};
+
+struct RelationshipData : public EntityData
+{
+    enum class Direction
+    {
+        Left,
+        Right
+    };
+
+    using nodes_t = std::pair<std::string, std::string>;
+
+    RelationshipData(nodes_t nodes, Direction direction)
+        : nodes(nodes), direction(direction)
+    {
+    }
+
+    std::pair<std::string, std::string> nodes;
+    Direction direction;
+};
+
+struct QueryActionData
+{
+    std::map<ParameterIndexKey, uint64_t> parameter_index;
+    std::map<std::string, ClauseAction> actions;
+    std::map<std::string, EntityData> entity_data;
+    std::map<std::string, RelationshipData> relationship_data;
+    CypherStateMachine csm;
+
+    QueryActionData() = default;
+    QueryActionData(QueryActionData &&other) = default;
+
+    void create_entity(const std::string &entity)
+    {
+        if (entity_data.find(entity) == entity_data.end())
+            entity_data.emplace(entity, EntityData());
+    }
+
+    void add_entity_tag(const std::string &entity, const std::string &tag)
+    {
+        create_entity(entity);
+        entity_data.at(entity).add_tag(tag);
+    }
+
+    void add_entitiy_property(const std::string &entity,
+                              const std::string &property)
+    {
+        create_entity(entity);
+        entity_data.at(entity).add_property(property);
+    }
+
+    // TODO: refactor name
+    auto get_entity_property(const std::string& entity) const
+    {
+        if (entity_data.find(entity) == entity_data.end())
+            throw CppGeneratorException("Entity doesn't exist");
+
+        return entity_data.at(entity);
+    }
+
+    void print() const
+    {
+        for (auto const &action : actions) {
+            std::cout << action.first << " " << underlying_cast(action.second)
+                      << std::endl;
+        }
+    }
+};

src/query_engine/code_generator/structures.hpp

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <vector>
+
+#include "utils/assert.hpp"
+
+template <class T>
+class Vector : public std::vector<T>
+{
+public:
+    using pair = std::pair<T, T>;
+
+    pair last_two()
+    {
+        runtime_assert(this->size() > 1, "Array size shoud be bigger than 1");
+
+        return std::make_pair(*(this->end() - 2), *(this->end() - 1));
+    }
+};

src/query_engine/exceptions/exceptions.hpp

@@ -0,0 +1,18 @@
+#pragma once
+
+#include "utils/exceptions/basic_exception.hpp"
+
+class QueryEngineException : public BasicException
+{
+    using BasicException::BasicException;
+};
+
+class SemanticException : public BasicException
+{
+    using BasicException::BasicException;
+};
+
+class CppGeneratorException : public BasicException
+{
+    using BasicException::BasicException;
+};

src/query_engine/exceptions/query_engine_exception.hpp

@@ -1,8 +0,0 @@
-#pragma once
-
-#include "utils/exceptions/basic_exception.hpp"
-
-class QueryEngineException : public BasicException
-{
-    using BasicException::BasicException;
-};

src/query_engine/hardcode/queries.hpp

@@ -68,38 +68,39 @@ auto load_queries(Db& db)
         auto v2 = db.graph.vertices.find(t, args[1]->as<Int32>().value);
         if (!v2) return t.commit(), false;
 
-        auto e = db.graph.edges.insert(t);
+        auto edge_accessor = db.graph.edges.insert(t);
 
-        v1.vlist->update(t)->data.out.add(e.vlist);
-        v2.vlist->update(t)->data.in.add(e.vlist);
+        v1.vlist->update(t)->data.out.add(edge_accessor.vlist);
+        v2.vlist->update(t)->data.in.add(edge_accessor.vlist);
 
-        e.from(v1.vlist);
-        e.to(v2.vlist);
+        edge_accessor.from(v1.vlist);
+        edge_accessor.to(v2.vlist);
         
         auto &edge_type = db.graph.edge_type_store.find_or_create("IS");
-        e.edge_type(edge_type);
+        edge_accessor.edge_type(edge_type);
 
         t.commit();
 
-        cout << e.edge_type() << endl;
-        cout_properties(e.properties());
+        cout << edge_accessor.edge_type() << endl;
+
+        cout_properties(edge_accessor.properties());
 
         return true;
     };
 
     auto find_edge_by_internal_id = [&db](const properties_t &args) {
         auto &t = db.tx_engine.begin();
-        auto e = db.graph.edges.find(t, args[0]->as<Int32>().value);
-        if (!e) return t.commit(), false;
+        auto edge_accessor = db.graph.edges.find(t, args[0]->as<Int32>().value);
+        if (!edge_accessor) return t.commit(), false;
 
         // print edge type and properties
-        cout << "EDGE_TYPE: " << e.edge_type() << endl;
+        cout << "EDGE_TYPE: " << edge_accessor.edge_type() << endl;
 
-        auto from = e.from();
+        auto from = edge_accessor.from();
         cout << "FROM:" << endl;
         cout_properties(from->find(t)->data.props);
 
-        auto to = e.to();
+        auto to = edge_accessor.to();
         cout << "TO:" << endl;
         cout_properties(to->find(t)->data.props);
 
@@ -139,6 +140,7 @@ auto load_queries(Db& db)
     queries[10597108978382323595u] = create_account;
     queries[5397556489557792025u] = create_labeled_and_named_node;
     queries[7939106225150551899u] = create_edge;
+    queries[6579425155585886196u] = create_edge;
     queries[11198568396549106428u] = find_node_by_internal_id;
     queries[8320600413058284114u] = find_edge_by_internal_id;
     queries[6813335159006269041u] = update_node;

src/query_engine/program_executor.hpp

@@ -6,7 +6,7 @@
 #include "query_engine/util.hpp"
 #include "query_program.hpp"
 #include "utils/log/logger.hpp"
-#include "query_engine/exceptions/query_engine_exception.hpp"
+#include "query_engine/exceptions/exceptions.hpp"
 
 //  preparations before execution
 //  execution

src/query_engine/program_loader.hpp

@@ -25,7 +25,7 @@ public:
     using sptr_code_lib = std::shared_ptr<CodeLib>;
 
     ProgramLoader()
-        : stripper(make_query_stripper(TK_INT, TK_FLOAT, TK_STR, TK_BOOL))
+        : stripper(make_query_stripper(TK_LONG, TK_FLOAT, TK_STR, TK_BOOL))
     {
     }
 
@@ -50,7 +50,9 @@ public:
         //  TODO load output path from config
         auto base_path = config::Config::instance()[config::COMPILE_CPU_PATH];
         auto path_cpp = base_path + hash_string + ".cpp";
-        code_generator.generate_cpp(query, stripped.hash, path_cpp);
+        auto stripped_space = stripper.strip_space(query);
+        code_generator.generate_cpp(stripped_space.query, stripped.hash,
+                                    path_cpp);
 
         auto path_so = base_path + hash_string + ".so";
         code_compiler.compile(path_cpp, path_so);

src/query_engine/query_engine.hpp

@@ -9,6 +9,11 @@
 // query -> code_loader -> query_stripper -> [code_generator]
 // -> [code_compiler] -> code_executor
 
+// TODO
+//     * query engine will get a pointer to currently active database
+//     * TCP server session will have pointer to dbms and currently active
+//     * database
+        
 class QueryEngine
 {
 public:

src/query_engine/query_hasher.hpp

@@ -8,7 +8,7 @@ class QueryHasher
 {
 public:
     QueryHasher()
-        : stripper(make_query_stripper(TK_INT, TK_FLOAT, TK_STR, TK_BOOL)) {}
+        : stripper(make_query_stripper(TK_LONG, TK_FLOAT, TK_STR, TK_BOOL)) {}
 
     std::string hash(std::string &query)
     {

src/query_engine/query_stripped.hpp

@@ -18,7 +18,7 @@ struct QueryStripped
     QueryStripped(QueryStripped &other) = delete;
     QueryStripped(QueryStripped &&other) = default;
 
-    code_args_t arguments;
-    uint64_t hash;
     std::string query;
+    uint64_t hash;
+    code_args_t arguments;
 };

src/query_engine/query_stripper.hpp

@@ -8,13 +8,12 @@
 
 #include "cypher/cypher.h"
 #include "cypher/tokenizer/cypher_lexer.hpp"
-#include "utils/hashing/fnv.hpp"
 #include "query_stripped.hpp"
 #include "storage/model/properties/all.hpp"
+#include "utils/hashing/fnv.hpp"
 #include "utils/string/transform.hpp"
 #include "utils/variadic/variadic.hpp"
 
-
 template <class T, class V>
 void store_query_param(code_args_t &arguments, V &&v)
 {
@@ -39,7 +38,13 @@ public:
     {
     }
 
-    auto strip(const std::string &query)
+    auto strip_space(const std::string &query)
+    {
+        auto stripped = strip(query, " ");
+        return QueryStripped(std::move(stripped.query), stripped.hash, std::move(stripped.arguments));
+    }
+
+    auto strip(const std::string &query, const std::string &separator = "")
     {
         //  TODO write this more optimal (resplace string
         //  concatenation with something smarter)
@@ -60,9 +65,9 @@ public:
             if (_or(token.id, strip_types, std::make_index_sequence<size>{})) {
                 auto index = counter++;
                 switch (token.id) {
-                case TK_INT:
-                    store_query_param<Int32>(stripped_arguments,
-                                             std::stoi(token.value));
+                case TK_LONG:
+                    store_query_param<Int64>(stripped_arguments,
+                                             std::stol(token.value));
                     break;
                 case TK_STR:
                     store_query_param<String>(stripped_arguments, token.value);
@@ -77,15 +82,14 @@ public:
                                              std::stof(token.value));
                     break;
                 }
-                stripped_query += std::to_string(index);
+                stripped_query += std::to_string(index) + separator;
             } else {
                 //  TODO: lowercase only keywords like (MATCH, CREATE, ...)
-                stripped_query += token.value;
+                stripped_query += token.value + separator;
             }
         }
 
-        return QueryStripped(std::move(stripped_query),
-                             fnv(stripped_query),
+        return QueryStripped(std::move(stripped_query), fnv(stripped_query),
                              std::move(stripped_arguments));
     }
 

src/query_engine/template/template_code_cpu.cpp

@@ -4,13 +4,6 @@
 #include "query_engine/i_code_cpu.hpp"
 #include "storage/model/properties/all.hpp"
 
-#ifdef DEBUG
-#include "query_engine/debug.hpp"
-#endif
-
-//  TODO generate with the template engine 
-// #include "storage/model/properties/jsonwriter.hpp"
-
 using std::cout;
 using std::endl;
 

src/query_engine/traverser/code.hpp

@@ -28,12 +28,22 @@ const std::string args_id = "auto id = args[{}]->as<Int32>();";
 const std::string vertex_accessor_args_id =
     "auto vertex_accessor = db.graph.vertices.find(t, id.value);";
 
+const std::string match_vertex_by_id =
+    "auto {0} = db.graph.vertices.find(t, args[{1}]->as<Int64>().value);\n"
+    "\tif (!{0}) return t.commit(), std::make_shared<QueryResult>();";
+
+const std::string create_edge =
+    "auto {} = db.graph.edges.insert(t);";
+
 const std::string vertex_set_property =
     "vertex_accessor.property(\"{}\", args[{}]);";
 
 const std::string return_empty_result =
     "return std::make_shared<QueryResult>();";
 
+const std::string update_property =
+    "{}.property(\"{}\", args[{}]);";
+
 const std::string create_label =
     "auto &{} = db.graph.label_store.find_or_create(\"{}\");";
 

src/query_engine/traverser/code_traverser.hpp

@@ -1,54 +0,0 @@
-#pragma once
-
-#include <string>
-
-#include "cypher/visitor/traverser.hpp"
-#include "cypher/ast/queries.hpp"
-#include "code.hpp"
-#include "write_traverser.hpp"
-#include "read_traverser.hpp"
-#include "update_traverser.hpp"
-#include "delete_traverser.hpp"
-#include "read_write_traverser.hpp"
-
-class CodeTraverser : public Traverser, public Code
-{
-public:
-
-    // TODO: remove code duplication
-
-    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;
-    }
-
-    void visit(ast::UpdateQuery& update_query) override
-    {
-        auto update_traverser = UpdateTraverser();
-        update_query.accept(update_traverser);
-        code = update_traverser.code;
-    }
-
-    void visit(ast::DeleteQuery& delete_query) override
-    {
-        auto delete_traverser = DeleteTraverser();
-        delete_query.accept(delete_traverser);
-        code = delete_traverser.code;
-    }
-
-    void visit(ast::ReadWriteQuery& read_write_query) override
-    {
-        auto read_write_traverser = ReadWriteTraverser();
-        read_write_query.accept(read_write_traverser);
-        code = read_write_traverser.code;
-    }
-};

src/query_engine/traverser/cpp_traverser.hpp

@@ -0,0 +1,410 @@
+#pragma once
+
+#include <string>
+
+#include "cypher/visitor/traverser.hpp"
+#include "query_engine/code_generator/cpp_generator.hpp"
+#include "query_engine/code_generator/entity_search.hpp"
+#include "query_engine/code_generator/structures.hpp"
+#include "query_engine/exceptions/exceptions.hpp"
+#include "query_engine/traverser/code.hpp"
+
+struct SetElementState
+{
+    std::string set_entity;
+    std::string set_prop;
+    int64_t set_index;
+
+    SetElementState() { clear(); }
+
+    bool is_defined() const
+    {
+        if (set_entity.empty()) return false;
+        if (set_prop.empty()) return false;
+        if (set_index < 0) return false;
+
+        return true;
+    }
+
+    void clear()
+    {
+        set_entity = "";
+        set_prop = "";
+        set_index = -1;
+    }
+};
+
+struct PropertyState
+{
+    std::string property_name;
+    int64_t property_index;
+
+    PropertyState() { clear(); }
+
+    bool is_defined() const
+    {
+        if (property_name.empty()) return false;
+        if (property_index < 0) return false;
+
+        return true;
+    }
+
+    void clear()
+    {
+        property_name = "";
+        property_index = -1;
+    }
+};
+
+// TODO: another idea is to user ast history in order to choose appropriate
+// action
+
+class CppTraverser : public Traverser, public Code
+{
+private:
+    // currently active entity name (node or relationship name)
+    std::string entity;
+
+    // currently active state
+    CypherState state; // TODO: move to generator
+    QueryAction query_action;
+    ClauseAction clause_action;
+
+    // linearization
+    CppGenerator generator;
+
+    Vector<std::string> visited_nodes;
+
+    RelationshipData::Direction direction;
+
+    SetElementState set_element_state;
+    PropertyState property_state;
+
+    void clear_state()
+    {
+        set_element_state.clear();
+        property_state.clear();
+    }
+
+public:
+    void visit(ast::WriteQuery &write_query) override
+    {
+        // TODO: crate top level node (TransactionBegin can be
+        // only at the one place)
+        generator.add_action(QueryAction::TransactionBegin);
+
+        Traverser::visit(write_query);
+    }
+
+    void visit(ast::ReadQuery &read_query) override
+    {
+        generator.add_action(QueryAction::TransactionBegin);
+
+        Traverser::visit(read_query);
+    }
+
+    void visit(ast::UpdateQuery &update_query) override
+    {
+        generator.add_action(QueryAction::TransactionBegin);
+
+        Traverser::visit(update_query);
+    }
+
+    void visit(ast::DeleteQuery &delete_query) override
+    {
+        generator.add_action(QueryAction::TransactionBegin);
+
+        Traverser::visit(delete_query);
+    }
+
+    void visit(ast::ReadWriteQuery &read_write_query) override
+    {
+        generator.add_action(QueryAction::TransactionBegin);
+
+        Traverser::visit(read_write_query);
+    }
+
+    void visit(ast::Match &ast_match) override
+    {
+        state = CypherState::Match;
+
+        generator.add_action(QueryAction::Match);
+
+        Traverser::visit(ast_match);
+    }
+
+    void visit(ast::Where &ast_where) override
+    {
+        state = CypherState::Where;
+
+        Traverser::visit(ast_where);
+    }
+
+    void visit(ast::Create &ast_create) override
+    {
+        code += generator.generate();
+        generator.add_action(QueryAction::Create);
+
+        state = CypherState::Create;
+        query_action = QueryAction::Create;
+
+        Traverser::visit(ast_create);
+    }
+
+    void visit(ast::Set &ast_set) override
+    {
+        code += generator.generate(); 
+
+        generator.add_action(QueryAction::Set);
+
+        state = CypherState::Set;
+        query_action = QueryAction::Set;
+
+        Traverser::visit(ast_set);
+    }
+
+    void visit(ast::Return &ast_return) override
+    {
+        generator.add_action(QueryAction::Return);
+
+        state = CypherState::Return;
+        query_action = QueryAction::Return;
+
+        Traverser::visit(ast_return);
+
+        // TODO: move commit somewhare that is more appropriate
+        generator.add_action(QueryAction::TransactionCommit);
+
+        code += generator.generate();
+
+        generator.clear();
+    }
+
+    void visit(ast::PatternList &ast_pattern_list) override
+    {
+        Traverser::visit(ast_pattern_list);
+    }
+
+    void visit(ast::Pattern &ast_pattern) override
+    {
+        // TODO: Is that traversal order OK for all cases? Probably NOT.
+        if (ast_pattern.has_next()) {
+            Traverser::visit(*(ast_pattern.next));
+            if (ast_pattern.has_node()) Traverser::visit(*(ast_pattern.node));
+            if (ast_pattern.has_relationship())
+                Traverser::visit(*(ast_pattern.relationship));
+        } else {
+            Traverser::visit(ast_pattern);
+        }
+    }
+
+    void visit(ast::Node &ast_node) override
+    {
+        auto &action_data = generator.action_data();
+        auto &cypher_data = generator.cypher_data();
+
+        if (!ast_node.has_identifier()) return;
+
+        auto name = ast_node.idn->name;
+        entity = name;
+        visited_nodes.push_back(name);
+
+        if (state == CypherState::Match) {
+            action_data.actions[name] = ClauseAction::MatchNode;
+        }
+
+        if (state == CypherState::Create) {
+            if (cypher_data.status(name) == EntityStatus::Matched) {
+                action_data.actions[name] = ClauseAction::MatchNode;
+            } else {
+                action_data.actions[name] = ClauseAction::CreateNode;
+            }
+        }
+
+        Traverser::visit(ast_node);
+    }
+
+    void visit(ast::And &ast_and) override { Traverser::visit(ast_and); }
+
+    void visit(ast::InternalIdExpr &internal_id_expr) override
+    {
+        if (!internal_id_expr.has_entity()) return;
+        if (!internal_id_expr.has_id()) return;
+
+        auto name = internal_id_expr.entity_name();
+        // because entity_id will be index of value inside parameters array
+        auto index = internal_id_expr.entity_id();
+
+        auto &data = generator.action_data();
+
+        data.parameter_index[ParameterIndexKey(InternalId, name)] = index;
+        data.csm.search_cost(name, entity_search::search_internal_id,
+                             entity_search::internal_id_cost);
+    }
+
+    // -- RELATIONSHIP --
+    void create_relationship(const std::string &name)
+    {
+        auto &data = generator.action_data();
+        data.actions[name] = ClauseAction::CreateRelationship;
+        auto nodes = visited_nodes.last_two();
+        data.relationship_data.emplace(name,
+                                       RelationshipData(nodes, direction));
+    }
+
+    void visit(ast::Relationship &ast_relationship) override
+    {
+        auto &cypher_data = generator.cypher_data();
+
+        if (ast_relationship.has_name()) entity = ast_relationship.name();
+
+        // TODO: simplify somehow
+        if (state == CypherState::Create) {
+            if (ast_relationship.has_name()) {
+                auto name = ast_relationship.name();
+                if (!cypher_data.exist(name)) {
+                    clause_action = ClauseAction::CreateRelationship;
+                    create_relationship(name);
+                }
+            }
+        }
+
+        using ast_direction = ast::Relationship::Direction;
+        using generator_direction = RelationshipData::Direction;
+
+        if (ast_relationship.direction == ast_direction::Left)
+            direction = generator_direction::Left;
+
+        if (ast_relationship.direction == ast_direction::Right)
+            direction = generator_direction::Right;
+
+        Traverser::visit(ast_relationship);
+
+        // TODO: add suport for Direction::Both
+    }
+
+    void visit(ast::RelationshipSpecs &ast_relationship_specs) override
+    {
+        Traverser::visit(ast_relationship_specs);
+    }
+
+    void visit(ast::RelationshipTypeList &ast_relationship_type_list) override
+    {
+        auto &data = generator.action_data();
+
+        if (ast_relationship_type_list.has_value()) {
+            auto type = ast_relationship_type_list.value->name;
+            data.add_entity_tag(entity, type);
+        }
+
+        Traverser::visit(ast_relationship_type_list);
+    }
+
+    void visit(ast::LabelList &ast_label_list) override
+    {
+        auto &data = generator.action_data();
+
+        if (!ast_label_list.has_value()) return;
+
+        auto label = ast_label_list.value->name;
+
+        data.add_entity_tag(entity, label);
+
+        Traverser::visit(ast_label_list);
+    }
+
+    void visit(ast::PropertyList &ast_property_list) override
+    {
+        Traverser::visit(ast_property_list);
+    }
+
+    void visit(ast::Property &ast_property) override
+    {
+        clear_state();
+
+        Traverser::visit(ast_property);
+
+        // TODO: too ugly refactor somehow (clear_state part is awful)
+        if (entity.empty() || !property_state.is_defined()) {
+            clear_state();
+            return;
+        }
+
+        auto prop = property_state.property_name;
+        auto index = property_state.property_index;
+
+        auto &data = generator.action_data();
+        data.parameter_index.emplace(ParameterIndexKey(entity, prop), index);
+        data.add_entitiy_property(entity, prop);
+
+        clear_state();
+    }
+
+    void visit(ast::Identifier &ast_identifier) override
+    {
+        property_state.property_name = ast_identifier.name;
+    }
+
+    void visit(ast::Long &ast_long) override
+    {
+        set_element_state.set_index = ast_long.value;
+        property_state.property_index = ast_long.value;
+    }
+
+    // -- SET subtree (node)
+    //      QUERY: SET n.name = "bla", ...
+    //      STRIP: SET n.name = 0, ...
+    //      STATE: entity: n; prop: name; set_index: 0
+
+    void visit(ast::SetList &ast_set_list) override
+    {
+        Traverser::visit(ast_set_list);
+    }
+
+    void visit(ast::SetElement &ast_set_element) override
+    {
+        Traverser::visit(ast_set_element);
+
+        if (!set_element_state.is_defined()) {
+            clear_state();
+            return;
+        }
+
+        auto entity = set_element_state.set_entity;
+        auto prop = set_element_state.set_prop;
+        auto index = set_element_state.set_index;
+
+        auto &cypher_data = generator.cypher_data();
+        auto entity_type = cypher_data.type(entity);
+
+        if (entity_type == EntityType::NotFound)
+            throw SemanticException("Set Entity (" + entity +
+                                    ") doesn't exist");
+
+        auto &action_data = generator.action_data();
+
+        if (entity_type == EntityType::Node)
+            action_data.actions[entity] = ClauseAction::UpdateNode;
+        if (entity_type == EntityType::Relationship)
+            action_data.actions[entity] = ClauseAction::UpdateRelationship;
+
+        action_data.parameter_index.emplace(ParameterIndexKey(entity, prop), index);
+        action_data.add_entitiy_property(entity, prop);
+
+        clear_state();
+    }
+
+    void visit(ast::Accessor &ast_accessor) override
+    {
+        if (!ast_accessor.has_entity()) return;
+        if (!ast_accessor.has_prop()) return;
+
+        set_element_state.set_entity = ast_accessor.entity_name();
+        set_element_state.set_prop = ast_accessor.entity_prop();
+    }
+
+    void visit(ast::SetValue &ast_set_value) override
+    {
+        Traverser::visit(ast_set_value);
+    }
+};

src/query_engine/traverser/del_read_traverser.hpp

@@ -5,9 +5,9 @@
 
 #include "code.hpp"
 #include "cypher/visitor/traverser.hpp"
-#include "query_engine/state_machine/cypher.hpp"
 #include "query_engine/util.hpp"
 #include "utils/underlying_cast.hpp"
+#include "query_engine/code_generator/entity_search.hpp"
 
 using namespace entity_search;
 

src/query_engine/traverser/del_read_write_traverser.hpp

@@ -0,0 +1,270 @@
+#pragma once
+
+#include "code.hpp"
+#include "cypher/visitor/traverser.hpp"
+#include "query_engine/code_generator/cypher_state.hpp"
+#include "query_engine/code_generator/cpp_generator.hpp"
+#include "query_engine/code_generator/structures.hpp"
+
+// k
+// auto v1 = db.graph.vertices.find(t, args[0]->as<Int32>().value);
+// if (!v1) return t.commit(), false;
+
+// auto v2 = db.graph.vertices.find(t, args[1]->as<Int32>().value);
+// if (!v2) return t.commit(), false;
+
+// create
+// auto edge_accessor = db.graph.edges.insert(t);
+
+// from
+// v1.vlist->update(t)->data.out.add(edge_accessor.vlist);
+// edge_accessor.from(v1.vlist);
+
+// to
+// v2.vlist->update(t)->data.in.add(edge_accessor.vlist);
+// edge_accessor.to(v2.vlist);
+
+// edge type
+// auto &edge_type = db.graph.edge_type_store.find_or_create("IS");
+// edge_accessor.edge_type(edge_type);
+
+class ReadWriteTraverser : public Traverser, public Code
+{
+private:
+    // currently active entity name (node or relationship name)
+    std::string entity;
+
+    // currenlty active parameter index
+    uint64_t index;
+
+    // currently active state
+    CypherState state; // TODO: move to generator
+    QueryAction query_action;
+    ClauseAction clause_action;
+
+    // linearization
+    CppGenerator generator;
+
+    Vector<std::string> visited_nodes;
+
+    RelationshipData::Direction direction;
+
+public:
+    void visit(ast::Match &ast_match) override
+    {
+        state = CypherState::Match;
+
+        generator.add_action(QueryAction::TransactionBegin);
+        generator.add_action(QueryAction::Match);
+
+        Traverser::visit(ast_match);
+    }
+
+    void visit(ast::Where &ast_where) override
+    {
+        state = CypherState::Where;
+
+        Traverser::visit(ast_where);
+    }
+
+    void visit(ast::Create &ast_create) override
+    {
+        // generate state before
+        generator.generate();
+
+        // save current action
+        generator.add_action(QueryAction::Create);
+
+        state = CypherState::Create;
+        query_action = QueryAction::Create;
+
+        Traverser::visit(ast_create);
+    }
+
+    void visit(ast::Return &ast_return) override
+    {
+        generator.add_action(QueryAction::Return);
+        generator.add_action(QueryAction::TransactionCommit);
+
+        state = CypherState::Return;
+        query_action = QueryAction::Return;
+
+        Traverser::visit(ast_return);
+
+        code = generator.generate();
+    }
+
+    void visit(ast::PatternList &ast_pattern_list) override
+    {
+        Traverser::visit(ast_pattern_list);
+    }
+
+    void visit(ast::Pattern &ast_pattern) override
+    {
+        // TODO: Is that traversal order OK for all cases? Probably NOT.
+        if (ast_pattern.has_next()) {
+            Traverser::visit(*(ast_pattern.next));
+            if (ast_pattern.has_node()) Traverser::visit(*(ast_pattern.node));
+            if (ast_pattern.has_relationship())
+                Traverser::visit(*(ast_pattern.relationship));
+        } else {
+            Traverser::visit(ast_pattern);
+        }
+    }
+
+    void visit(ast::Node &ast_node) override
+    {
+        auto &action_data = generator.action_data();
+        auto &cypher_data = generator.cypher_data();
+
+        if (!ast_node.has_identifier()) return;
+
+        auto name = ast_node.idn->name;
+        entity = name;
+        visited_nodes.push_back(name);
+
+        if (state == CypherState::Match) {
+            action_data.actions[name] = ClauseAction::MatchNode;
+        }
+
+        if (state == CypherState::Create) {
+            if (cypher_data.status(name) == EntityStatus::Matched) {
+                action_data.actions[name] = ClauseAction::MatchNode;
+            } else {
+                action_data.actions[name] = ClauseAction::CreateNode;
+            }
+        }
+
+        Traverser::visit(ast_node);
+    }
+
+    void visit(ast::And &ast_and) override { Traverser::visit(ast_and); }
+
+    void visit(ast::InternalIdExpr &internal_id_expr) override
+    {
+        if (internal_id_expr.identifier == nullptr) return;
+        auto name = internal_id_expr.identifier->name;
+
+        // value has to exist
+        if (internal_id_expr.value == nullptr) {
+            // TODO: raise exception
+        }
+
+        auto &data = generator.action_data();
+        data.parameter_index[ParameterIndexKey(InternalId, name)] = index++;
+        data.csm.search_cost(name, search_internal_id, internal_id_cost);
+    }
+
+    // -- RELATIONSHIP --
+    void create_relationship(const std::string &name)
+    {
+        auto &data = generator.action_data();
+        data.actions[name] = ClauseAction::CreateRelationship;
+        auto nodes = visited_nodes.last_two();
+        data.relationship_data.emplace(name,
+                                       RelationshipData(nodes, direction));
+    }
+
+    void visit(ast::Relationship &ast_relationship) override
+    {
+        auto &cypher_data = generator.cypher_data();
+
+        if (ast_relationship.has_name()) entity = ast_relationship.name();
+
+        // TODO: simplify somehow
+        if (state == CypherState::Create) {
+            if (ast_relationship.has_name()) {
+                auto name = ast_relationship.name();
+                if (!cypher_data.exist(name)) {
+                    clause_action = ClauseAction::CreateRelationship;
+                    create_relationship(name);
+                }
+            }
+        }
+
+        using ast_direction = ast::Relationship::Direction;
+        using generator_direction = RelationshipData::Direction;
+
+        if (ast_relationship.direction == ast_direction::Left)
+            direction = generator_direction::Left;
+
+        if (ast_relationship.direction == ast_direction::Right)
+            direction = generator_direction::Right;
+
+        Traverser::visit(ast_relationship);
+
+        // TODO: add suport for Direction::Both
+    }
+
+    void visit(ast::RelationshipSpecs &ast_relationship_specs) override
+    {
+        Traverser::visit(ast_relationship_specs);
+    }
+
+    void visit(ast::RelationshipTypeList &ast_relationship_type_list) override
+    {
+        auto &data = generator.action_data();
+
+        if (ast_relationship_type_list.has_value()) {
+            auto type = ast_relationship_type_list.value->name;
+            data.add_entity_tag(entity, type);
+        }
+
+        Traverser::visit(ast_relationship_type_list);
+    }
+
+    void visit(ast::LabelList &ast_label_list) override
+    {
+        auto &data = generator.action_data();
+
+        if (!ast_label_list.has_value()) return;
+
+        auto label = ast_label_list.value->name;
+
+        data.add_entity_tag(entity, label);
+
+        Traverser::visit(ast_label_list);
+    }
+
+    void visit(ast::PropertyList& ast_property_list) override
+    {
+        Traverser::visit(ast_property_list);
+    }
+
+    void visit(ast::Property &ast_property) override
+    {
+        auto &data = generator.action_data();
+
+        if (!ast_property.has_name()) return;
+
+        auto name = ast_property.name();
+
+        data.parameter_index.emplace(ParameterIndexKey(entity, name), index++);
+
+        Traverser::visit(ast_property);
+    }
+
+    // -- SET --
+
+    void visit(ast::SetList &ast_set_list) override
+    {
+        Traverser::visit(ast_set_list);
+    }
+
+    void visit(ast::SetElement &ast_set_element) override
+    {
+        Traverser::visit(ast_set_element);
+    }
+
+    void visit(ast::Accessor &ast_accessor) override
+    {
+        auto &data = generator.action_data();
+
+        if (ast_accessor.has_entity() && ast_accessor.has_prop()) {
+            auto entity = ast_accessor.entity_name();
+            auto prop = ast_accessor.entity_prop();
+            data.parameter_index.emplace(ParameterIndexKey(entity, prop),
+                                         index++);
+        }
+    }
+};

src/query_engine/traverser/delete_traverser.hpp

@@ -1,18 +0,0 @@
-#pragma once
-
-#include "code.hpp"
-#include "cypher/visitor/traverser.hpp"
-
-class DeleteTraverser : public Traverser, public Code
-{
-    void visit(ast::Match& match) override
-    {
-        code += LINE(fmt::format(code::todo, "MATCH"));
-    }
-
-    void visit(ast::Delete& delete_clause) override
-    {
-        code += LINE(fmt::format(code::todo, "DELETE"));
-        code += LINE(code::return_empty_result);
-    }
-};

src/query_engine/traverser/read_write_traverser.hpp

@@ -1,31 +0,0 @@
-#pragma once
-
-#include "code.hpp"
-#include "cypher/visitor/traverser.hpp"
-
-class ReadWriteTraverser : public Traverser, public Code
-{
-    void visit(ast::Match& match) override
-    {
-        code += LINE(fmt::format(code::todo, "MATCH"));
-        Traverser::visit(match);
-    }
-
-    void visit(ast::Where& where) override
-    {
-        code += LINE(fmt::format(code::todo, "WHERE"));
-        Traverser::visit(where);
-    }
-
-    void visit(ast::Create& create) override
-    {
-        code += LINE(fmt::format(code::todo, "CREATE"));
-        Traverser::visit(create);
-    }
-
-    void visit(ast::Return& ast_return) override
-    {
-        code += LINE(fmt::format(code::todo, "RETURN"));
-        code += LINE(code::return_empty_result);
-    }
-};

src/query_engine/traverser/update_traverser.hpp

@@ -1,23 +0,0 @@
-#pragma once
-
-#include "code.hpp"
-#include "cypher/visitor/traverser.hpp"
-
-class UpdateTraverser : public Traverser, public Code
-{
-    void visit(ast::Match& match) override
-    {
-        code += LINE(fmt::format(code::todo, "MATCH"));
-    }
-
-    void visit(ast::Set& set) override
-    {
-        code += LINE(fmt::format(code::todo, "SET"));
-    }
-
-    void visit(ast::Return& ret) override
-    {
-        code += LINE(fmt::format(code::todo, "RETURN"));
-        code += LINE(code::return_empty_result);
-    }
-};

tests/CMakeLists.txt

@@ -61,16 +61,31 @@ set_property(TARGET integration_queries PROPERTY CXX_STANDARD 14)
 
 ## MANUAL TESTS
 
-# query engine
+# cypher_ast
+add_executable(manual_cypher_ast manual/cypher_ast.cpp ${memgraph_src_files})
+target_link_libraries(manual_cypher_ast ${fmt_static_lib})
+target_link_libraries(manual_cypher_ast cypher_lib)
+set_property(TARGET manual_cypher_ast PROPERTY CXX_STANDARD 14)
+
+# queries
+add_executable(manual_queries manual/queries.cpp ${memgraph_src_files})
+target_link_libraries(manual_queries ${fmt_static_lib})
+target_link_libraries(manual_queries cypher_lib)
+set_property(TARGET manual_queries PROPERTY CXX_STANDARD 14)
+
+# query_engine
 add_executable(manual_query_engine manual/query_engine.cpp ${memgraph_src_files})
 target_link_libraries(manual_query_engine ${fmt_static_lib})
 target_link_libraries(manual_query_engine dl)
 target_link_libraries(manual_query_engine cypher_lib)
 set_property(TARGET manual_query_engine PROPERTY CXX_STANDARD 14)
 
-# ast traversal
-add_executable(cypher_ast_traverser manual/cypher_ast.cpp ${mamgraph_src_files})
-target_link_libraries(cypher_ast_traverser ${fmt_static_lib})
-target_link_libraries(cypher_ast_traverser cypher_lib)
-set_property(TARGET cypher_ast_traverser PROPERTY CXX_STANDARD 14)
+# query_hasher
+add_executable(manual_query_hasher manual/query_hasher.cpp ${memgraph_src_files})
+target_link_libraries(manual_query_hasher ${fmt_static_lib})
+set_property(TARGET manual_query_hasher PROPERTY CXX_STANDARD 14)
 
+# query_action_processor
+add_executable(manual_cpp_generator manual/cpp_generator.cpp ${memgraph_src_files})
+target_link_libraries(manual_cpp_generator ${fmt_static_lib})
+set_property(TARGET manual_cpp_generator PROPERTY CXX_STANDARD 14)

tests/integration/queries.cpp

@@ -7,7 +7,7 @@ int main(void)
 
     auto query_functions = load_queries(db);
 
-    auto stripper = make_query_stripper(TK_INT, TK_FLOAT, TK_STR, TK_BOOL);
+    auto stripper = make_query_stripper(TK_LONG, TK_FLOAT, TK_STR, TK_BOOL);
 
     // TODO: put all queries into a file
     std::vector<std::string> queries = {

tests/manual/cpp_generator.cpp

@@ -0,0 +1,34 @@
+#include <iostream>
+
+#include "query_engine/code_generator/cpp_generator.hpp"
+
+using ParameterIndexKey::Type::InternalId;
+using ParameterIndexKey::Type::Projection;
+
+auto main() -> int
+{
+    CppGenerator generator;
+    
+    // MATCH
+    generator.add_action(QueryAction::Match);
+
+    auto& data_match = generator.action_data();
+    data_match.actions["n1"] = ClauseAction::MatchNode;
+    data_match.actions["n2"] = ClauseAction::MatchNode;
+
+    // CREATE
+    generator.add_action(QueryAction::Create);
+
+    auto& data_create = generator.action_data();
+    data_create.actions["r"] = ClauseAction::CreateRelationship;
+
+    // RETURN
+    generator.add_action(QueryAction::Return);
+
+    auto& data_return = generator.action_data();
+    data_return.actions["r"] = ClauseAction::ReturnRelationship;
+
+    generator.generate();
+
+    return 0;
+}

tests/manual/main_queries.cpp.old

@@ -1,143 +0,0 @@
-#include <iostream>
-
-#include "query_engine/hardcode/queries.hpp"
-
-using namespace std;
-
-// --
-// DESCRIPTION: create account
-// FULL:        CREATE (n:ACCOUNT {id: 50, name: "Nikola", country: "Croatia",
-// created_at: 14634563}) RETURN n
-// STRIPPED:    CREATE(n:ACCOUNT{id:0,name:1,country:2,created_at:3})RETURNn
-// HASH:        10597108978382323595
-// STATUS:      DONE
-// --
-// DESCRIPTION: create personnel
-// FULL:        CREATE (n:PERSONNEL {id: 23, role: "CTO", created_at: 1235345})
-// RETURN n
-// STRIPPED:    CREATE(n:PERSONNEL{id:0,role:1,created_at:2})RETURNn
-// HASH:        4037885257628527960
-// STATUS:      TODO
-// --
-// DESCRIPTION: create edge between ACCOUNT node and PERSONNEL node (IS type)
-// FULL:        MATCH (a:ACCOUNT {id:50}), (p:PERSONNEL {id: 23}) CREATE
-// (a)-[:IS]->(p)
-// STRIPPED:    MATCH(a:ACCOUNT{id:0}),(p:PERSONNEL{id:1})CREATE(a)-[:IS]->(p)
-// HASH:        16888190822925675190
-// STATUS:      TODO
-// --
-// DESCRIPTION: find ACCOUNT node, PERSONNEL node and edge between them
-// FULL:        MATCH (a:ACCOUNT {id:50})-[r:IS]->(p:PERSONNEL {id: 23}) RETURN
-// a,r,p
-// STRIPPED:    MATCH(a:ACCOUNT{id:0})-[r:IS]->(p:PERSONNEL{id:1})RETURNa,r,p
-// HASH:        9672752533852902744
-// STATUS:      TODO
-// --
-// DESCRIPTION: create OPPORTUNITY
-// FULL:
-// STRIPPED:
-// HASH:
-// STATUS:      TODO
-// --
-// DESCRIPTION: create PERSONNEL-[:CREATED]->OPPORTUNITY
-// FULL:
-// STRIPPED:
-// HASH:
-// STATUS:      TODO
-// --
-// DESCRIPTION: create COMPANY
-// FULL:
-// STRIPPED:
-// HASH:
-// STATUS:      TODO
-// --
-// DESCRIPTION: create OPPORTUNITY-[:MATCH]->COMPANY
-// FULL:
-// STRIPPED:
-// HASH:
-// STATUS:      TODO
-// --
-// DESCRIPTION: create an edge between two nodes that are found by the ID
-// FULL:        MATCH (a {id:0}), (p {id: 1}) CREATE (a)-[r:IS]->(p) RETURN r
-// STRIPPED:    MATCH(a{id:0}),(p{id:1})CREATE(a)-[r:IS]->(p)RETURNr
-// HASH:        7939106225150551899
-// STATUS:      DONE
-// --
-// DESCRIPTION: fine node by the ID
-// FULL:        MATCH (n {id: 0}) RETURN n
-// STRIPPED:    MATCH(n{id:0})RETURNn
-// HASH:        11198568396549106428
-// STATUS:      DONE
-// --
-// DESCRIPTION: find edge by the ID
-// FULL:        MATCH ()-[r]-() WHERE ID(r)=0 RETURN r
-// STRIPPED:    MATCH()-[r]-()WHEREID(r)=0RETURNr
-// HASH:        8320600413058284114
-// STATUS:      DONE
-// --
-// DESCRIPTION: update node that is found by the ID
-// FULL:        MATCH (n: {id: 0}) SET n.name = "TEST100" RETURN n
-// STRIPPED:    MATCH(n:{id:0})SETn.name=1RETURNn
-// HASH:        6813335159006269041
-// STATUS:      DONE
-// --
-// DESCRIPTION: find shortest path between two nodes specified by ID
-// FULL:
-// STRIPPED:
-// HASH:
-// STATUS:      TODO
-// --
-// DESCRIPTION: find all nodes by label name
-// FULL:        MATCH (n:LABEL) RETURN n
-// STRIPPPED:   MATCH(n:LABEL)RETURNn
-// HASH:        4857652843629217005
-// STATUS:      DONE
-// --
-// TODO: Labels and Types have to be extracted from a query during the
-// query compile time
-
-// void cout_properties(const Properties &properties)
-// {
-//     ConsoleWriter writer;
-//     properties.accept(writer);
-// }
-
-int main(int argc, char **argv)
-{
-    Db db;
-    auto queries = load_queries(db);
-
-    // auto arguments = all_arguments(argc, argv);
-    // auto input_query = extract_query(arguments);
-    auto stripper = make_query_stripper(TK_INT, TK_FLOAT, TK_STR, TK_BOOL);
-    // auto stripped = stripper.strip(input_query);
-    //
-    // auto time = timer<ms>([&stripped, &queries]() {
-    //     for (int i = 0; i < 1000000; ++i) {
-    //         queries[stripped.hash](stripped.arguments);
-    //     }
-    // });
-    // std::cout << time << std::endl;
-
-    vector<string> history;
-    string command;
-    cout << "-- Memgraph query engine --" << endl;
-    do {
-
-        cout << "> ";
-        getline(cin, command);
-        history.push_back(command);
-        auto stripped = stripper.strip(command);
-
-        if (queries.find(stripped.hash) == queries.end()) {
-            cout << "unsupported query" << endl;
-            continue;
-        }
-
-        auto result = queries[stripped.hash](stripped.arguments);
-        cout << "RETURN: " << result << endl;
-
-    } while (command != "quit");
-
-    return 0;
-}

tests/manual/main_query_engine.cpp.old

@@ -1,49 +0,0 @@
-#include <iostream>
-
-#define DEBUG 1
-
-#include "utils/command_line/arguments.hpp"
-#include "cypher/common.hpp"
-#include "query_engine.hpp"
-#include "utils/time/timer.hpp"
-
-using std::cout;
-using std::endl;
-using std::cin;
-
-int main(int argc, char** argv)
-{   
-    // arguments parsing
-    auto arguments = all_arguments(argc, argv);
-
-    // query extraction
-    auto cypher_query = extract_query(arguments);
-    cout << "QUERY: " << cypher_query << endl;
-    QueryEngine engine;
-    engine.execute(cypher_query);
-
-    // using std::placeholders::_1;
-    // auto f = std::bind(&QueryEngine::execute, &engine, _1);
-
-    // cout << std::fixed << timer(f, cypher_query) << endl;
-
-    // double counter = 0;
-    // for (int i = 0; i < 1000000; ++i) {
-    //     counter += timer(f, cypher_query);
-    // }
-    // cout << 1000000 / (counter / 1000000000) << "create_transactions per sec" << endl;
-    
-    // shell
-    std::string command;
-    cout << "-- Memgraph query engine --" << endl;
-    do {
-        cout << "> ";
-        std::getline(cin, command);
-        engine.execute(command);
-    } while (command != "quit");
-    
-    // engine.execute("CREATE (n{id:2}) RETURN n");
-    // engine.execute("MATCH (n{id:0}) RETURN n");
-
-    return 0;
-}

tests/manual/queries.cpp

@@ -0,0 +1,45 @@
+#include <iostream>
+
+#include "query_engine/hardcode/queries.hpp"
+
+using namespace std;
+
+int main(int argc, char **argv)
+{
+    Db db;
+    auto queries = load_queries(db);
+
+    // auto arguments = all_arguments(argc, argv);
+    // auto input_query = extract_query(arguments);
+    auto stripper = make_query_stripper(TK_LONG, TK_FLOAT, TK_STR, TK_BOOL);
+    // auto stripped = stripper.strip(input_query);
+    //
+    // auto time = timer<ms>([&stripped, &queries]() {
+    //     for (int i = 0; i < 1000000; ++i) {
+    //         queries[stripped.hash](stripped.arguments);
+    //     }
+    // });
+    // std::cout << time << std::endl;
+
+    vector<string> history;
+    string command;
+    cout << "-- Memgraph query engine --" << endl;
+    do {
+
+        cout << "> ";
+        getline(cin, command);
+        history.push_back(command);
+        auto stripped = stripper.strip(command);
+
+        if (queries.find(stripped.hash) == queries.end()) {
+            cout << "unsupported query" << endl;
+            continue;
+        }
+
+        auto result = queries[stripped.hash](stripped.arguments);
+        cout << "RETURN: " << result << endl;
+
+    } while (command != "quit");
+
+    return 0;
+}

tests/manual/query_hasher.cpp

@@ -1,8 +1,8 @@
 #include <iostream>
 
-#include "query_hasher.hpp"
 #include "cypher/common.hpp"
-#include "query_stripper.hpp"
+#include "query_engine/query_hasher.hpp"
+#include "query_engine/query_stripper.hpp"
 #include "utils/command_line/arguments.hpp"
 #include "utils/type_discovery.hpp"
 
@@ -20,7 +20,7 @@ int main(int argc, char** argv)
 
     cout << "QUERY: " << input_query << endl;
     
-    auto stripper = make_query_stripper(TK_INT, TK_FLOAT, TK_STR, TK_BOOL);
+    auto stripper = make_query_stripper(TK_LONG, TK_FLOAT, TK_STR, TK_BOOL);
     auto stripped = stripper.strip(input_query);
 
     cout << "STRIPPED QUERY: " << stripped.query << endl;

tests/unit/cypher_state_machine.cpp

@@ -1,6 +1,6 @@
 #include <iostream>
 
-#include "query_engine/state_machine/cypher.hpp"
+#include "query_engine/code_generator/entity_search.hpp"
 #include "utils/assert.hpp"
 #include "utils/underlying_cast.hpp"
 

tests/unit/parameter_index.cpp

@@ -0,0 +1,19 @@
+#include <iostream>
+
+#include "query_engine/code_generator/query_action_data.hpp"
+#include "utils/assert.hpp"
+
+using ParameterIndexKey::Type::InternalId;
+using ParameterIndexKey::Type::Projection;
+
+auto main() -> int
+{
+    std::map<ParameterIndexKey, uint64_t> parameter_index; 
+
+    parameter_index[ParameterIndexKey(InternalId, "n1")] = 0;
+    parameter_index[ParameterIndexKey(InternalId, "n2")] = 1;
+
+    permanent_assert(parameter_index.size() == 2, "Parameter index size should be 2");
+
+    return 0;
+}