MATCH ... SET ... RETURN clause

.gitignore

@@ -9,3 +9,4 @@
 memgraph
 *~
 *.pyc
+*.breakpoint

cypher/ast/ast.hpp

@@ -16,3 +16,4 @@
 #include "match.hpp"
 #include "queries.hpp"
 #include "start.hpp"
+#include "set.hpp"

cypher/ast/ast_visitor.hpp

@@ -40,29 +40,34 @@ struct Relationship;
 
 struct Node;
 struct LabelList;
-
 struct Pattern;
 
 struct Return;
 struct ReturnList;
 struct Distinct;
-struct Delete;
-
-struct Match;
-struct Where;
-
-struct Start;
-struct ReadQuery;
-struct WriteQuery;
-struct DeleteQuery;
 
 struct Create;
+struct Match;
+struct Where;
+struct Set;
+struct Delete;
+
+struct Start;
+struct WriteQuery;
+struct ReadQuery;
+struct UpdateQuery;
+struct DeleteQuery;
+
+struct SetKey;
+struct SetValue;
+struct SetElement;
+struct SetList;
 
 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, Match, ReadQuery,
     Start, Where, WriteQuery, Create, Return, Distinct, Delete,
-    DeleteQuery> {};
+    DeleteQuery, UpdateQuery, Set, SetKey, SetValue, SetElement, SetList> {};
 
 }

cypher/ast/queries.hpp

@@ -1,14 +1,24 @@
 #pragma once
 
 #include "ast_node.hpp"
-#include "match.hpp"
-#include "return.hpp"
 #include "create.hpp"
+#include "match.hpp"
+#include "set.hpp"
 #include "delete.hpp"
+#include "return.hpp"
 
 namespace ast
 {
 
+struct WriteQuery : public AstNode<WriteQuery>
+{
+    WriteQuery(Create* create, Return* return_clause)
+        : create(create), return_clause(return_clause) {}
+
+    Create* create;
+    Return* return_clause;
+};
+
 struct ReadQuery : public AstNode<ReadQuery>
 {
     ReadQuery(Match* match, Return* return_clause)
@@ -18,12 +28,16 @@ struct ReadQuery : public AstNode<ReadQuery>
     Return* return_clause;
 };
 
-struct WriteQuery : public AstNode<WriteQuery>
+struct UpdateQuery : public AstNode<UpdateQuery>
 {
-    WriteQuery(Create* create, Return* return_clause)
-        : create(create), return_clause(return_clause) {}
+    UpdateQuery(Match* match_clause, Set* set_clause, Return* return_clause)
+        : match_clause(match_clause), set_clause(set_clause),
+          return_clause(return_clause)
+    {
+    }
 
-    Create* create;
+    Match* match_clause;
+    Set* set_clause;
     Return* return_clause;
 };
 

cypher/ast/set.hpp

@@ -0,0 +1,58 @@
+#pragma once
+
+#include "accessor.hpp"
+#include "list.hpp"
+#include "expr.hpp"
+
+namespace ast
+{
+//
+//                    SetList
+//                       ^
+//                       |
+//       |------------------------------------|
+//                              SetElement
+//                                  ^
+//                                  |
+//                        |-------------------|
+//                         Accessor    SetValue
+//                            ^           ^
+//                            |           |
+//                        |-------|   |-------|
+//   SET n.name = "Paul", n.surname = "Scholes"
+//       ^                     ^
+//       |                     |
+//  element entity        element property
+//
+
+struct SetValue : public AstNode<SetValue>
+{
+    SetValue(Expr* value)
+        : value(value) {}
+
+    Expr* value;
+};
+
+struct SetElement : public AstNode<SetElement>
+{
+    SetElement(Accessor* accessor, SetValue* set_value)
+        : accessor(accessor), set_value(set_value) {}
+
+    Accessor* accessor;
+    SetValue* set_value;
+};
+
+struct SetList : public List<SetElement, SetList>
+{
+    using List::List;
+};
+
+struct Set : public AstNode<Set>
+{
+    Set(SetList* set_list)
+        : set_list(set_list) {}
+
+    SetList* set_list;
+};
+
+}

cypher/ast/start.hpp

@@ -8,25 +8,16 @@ namespace ast
 
 struct Start : public AstNode<Start>
 {
-    Start(ReadQuery* read_query) 
-        : read_query(read_query)
-    {
-    }
-
-    Start(WriteQuery* write_query) 
-        : write_query(write_query)
-    {
-    }
-
-    Start(DeleteQuery* delete_query) 
-        : delete_query(delete_query)
-    {
-    }
+    Start(WriteQuery* write_query) : write_query(write_query) {}
+    Start(ReadQuery* read_query) : read_query(read_query) {}
+    Start(UpdateQuery* update_query) : update_query(update_query) {}
+    Start(DeleteQuery* delete_query) : delete_query(delete_query) {}
 
     // TODO: the start structure must have a different implementation
     // is this class necessary?
-    ReadQuery* read_query{nullptr};
     WriteQuery* write_query {nullptr};
+    ReadQuery* read_query {nullptr};
+    UpdateQuery* update_query {nullptr};
     DeleteQuery* delete_query {nullptr};
 };
 

cypher/cypher.y

@@ -55,24 +55,20 @@
 
 // start structure
 
-start ::= read_query(RQ). {
-    ast->root = ast->create<ast::Start>(RQ);
-}
-
 start ::= write_query(WQ). {
     ast->root = ast->create<ast::Start>(WQ);
 }
 
-start ::= delete_query(DQ). {
-    ast->root = ast->create<ast::Start>(DQ);
+start ::= read_query(RQ). {
+    ast->root = ast->create<ast::Start>(RQ);
 }
 
-// read query structure
+start ::= update_query(UQ). {
+    ast->root = ast->create<ast::Start>(UQ);
+}
 
-%type read_query {ast::ReadQuery*}
-
-read_query(RQ) ::= match_clause(M) return_clause(R). {
-    RQ = ast->create<ast::ReadQuery>(M, R);
+start ::= delete_query(DQ). {
+    ast->root = ast->create<ast::Start>(DQ);
 }
 
 // write query structure
@@ -87,6 +83,34 @@ write_query(WQ) ::= create_clause(C). {
     WQ = ast->create<ast::WriteQuery>(C, nullptr);
 }
 
+// read query structure
+
+%type read_query {ast::ReadQuery*}
+
+read_query(RQ) ::= match_clause(M) return_clause(R). {
+    RQ = ast->create<ast::ReadQuery>(M, R);
+}
+
+// update query structure
+
+%type update_query {ast::UpdateQuery*}
+
+update_query(UQ) ::= match_clause(M) set_clause(S) return_clause(R). {
+    UQ = ast->create<ast::UpdateQuery>(M, S, R);
+}
+
+update_query(UQ) ::= match_clause(M) set_clause(S). {
+    UQ = ast->create<ast::UpdateQuery>(M, S, nullptr);
+}
+
+// set clause
+
+%type set_clause {ast::Set*}
+
+set_clause(S) ::= SET set_list(L). {
+    S = ast->create<ast::Set>(L);
+} 
+
 // delete query structure
 
 %type delete_query {ast::DeleteQuery*}
@@ -250,6 +274,9 @@ distinct(R) ::= DISTINCT idn(I). {
     R = ast->create<ast::Distinct>(I);
 }
 
+// list of properties
+// e.g. { name: "wayne", surname: "rooney"}
+
 %type properties {ast::PropertyList*}
 
 // '{' <property_list> '}'
@@ -343,12 +370,6 @@ idn(I) ::= IDN(X). {
     I = ast->create<ast::Identifier>(X->value);
 }
 
-//%type alias {ast::Alias*}
-//
-//alias(A) ::= IDN(X) AS IDN(Y). {
-//    A = ast->create<ast::Alias>(X->value, Y->value);
-//}
-
 expr(E) ::= INT(V). {
     auto value = std::stoi(V->value);
     E = ast->create<ast::Integer>(value);
@@ -369,3 +390,39 @@ expr(E) ::= BOOL(V). {
     E = ast->create<ast::Boolean>(value);
 }
 
+//%type alias {ast::Alias*}
+//
+//alias(A) ::= IDN(X) AS IDN(Y). {
+//    A = ast->create<ast::Alias>(X->value, Y->value);
+//}
+
+// set list
+// e.g. MATCH (n) SET n.name = "Ryan", n.surname = "Giggs" RETURN n
+
+%type set_list {ast::SetList*}
+
+set_list(L) ::= set_element(E) COMMA set_list(N). {
+    L = ast->create<ast::SetList>(E, N);
+}
+
+set_list(L) ::= set_element(E). {
+    L = ast->create<ast::SetList>(E, nullptr);
+}
+
+%type set_element {ast::SetElement*}
+
+set_element(E) ::= accessor(A) EQ set_value(V). {
+    E = ast->create<ast::SetElement>(A, V);
+}
+
+%type accessor {ast::Accessor*}
+
+accessor(A) ::= idn(E) DOT idn(P). {
+    A = ast->create<ast::Accessor>(E, P);
+}
+
+%type set_value {ast::SetValue*}
+
+set_value(V) ::= expr(E). {
+    V = ast->create<ast::SetValue>(E);
+}

cypher/cypher_lexer.hpp

@@ -44,12 +44,13 @@ public:
         rule("(?i:FALSE)", TK_BOOL);
 
         // keywords
+        rule("(?i:CREATE)", TK_CREATE);
         rule("(?i:MATCH)", TK_MATCH);
         rule("(?i:WHERE)", TK_WHERE);
+        rule("(?i:SET)", TK_SET);
         rule("(?i:RETURN)", TK_RETURN);
-        rule("(?i:DELETE)", TK_DELETE);
-        rule("(?i:CREATE)", TK_CREATE);
         rule("(?i:DISTINCT)", TK_DISTINCT);
+        rule("(?i:DELETE)", TK_DELETE);
 
         rule("(?i:AND)", TK_AND);
         rule("(?i:OR)", TK_OR);

cypher/debug/tree_print.hpp

@@ -317,6 +317,36 @@ public:
         Traverser::visit(create);
     }
 
+    void visit(ast::UpdateQuery& update_query) override
+    {
+        auto entry = printer.advance("Update Query");
+        Traverser::visit(update_query);
+    }
+
+    void visit(ast::Set& set_clause) override
+    {
+        auto entry = printer.advance("Set");
+        Traverser::visit(set_clause);
+    }
+
+    void visit(ast::SetValue& set_value) override
+    {
+        auto entry = printer.advance("Set Value");
+        Traverser::visit(set_value);
+    }
+
+    void visit(ast::SetElement& set_element) override
+    {
+        auto entry = printer.advance("Set Element");
+        Traverser::visit(set_element);
+    }
+
+    void visit(ast::SetList& set_list) override
+    {
+        auto entry = printer.advance("Set List");
+        Traverser::visit(set_list);
+    }
+
 private:
     Printer printer;
 };

cypher/query/read-write/match-set-return.cypher

@@ -0,0 +1 @@
+MATCH (n {surname:"Neville"}) SET n.surname="Neville", n.age=30 RETURN n

cypher/query/read-write/match-set.cypher

@@ -0,0 +1 @@
+MATCH (n {age: 30, role: "player"}) SET n.age=31

cypher/query/write/create.cypher

@@ -1 +1 @@
-CREATE (n {name: {value}})
+CREATE (n {name: "value"})

cypher/visitor/traverser.hpp

@@ -1,7 +1,7 @@
 #pragma once
 
-#include "cypher/ast/ast_visitor.hpp"
 #include "cypher/ast/ast.hpp"
+#include "cypher/ast/ast_visitor.hpp"
 
 class Traverser : public ast::AstVisitor
 {
@@ -12,10 +12,12 @@ public:
 
     void visit(ast::Start& start) override
     {
+        if (start.write_query != nullptr)
+            accept(start.write_query);
         if (start.read_query != nullptr)
             accept(start.read_query);
-        if (start.read_query != nullptr)
-            accept(start.write_query);
+        if (start.update_query != nullptr)
+            accept(start.update_query);
         if (start.delete_query != nullptr)
             accept(start.delete_query);
     }
@@ -196,6 +198,37 @@ public:
         accept(write_query.return_clause);
     }
 
+    void visit(ast::UpdateQuery& update_query) override
+    {
+        accept(update_query.match_clause);
+        accept(update_query.set_clause);
+        if (update_query.return_clause != nullptr)
+            accept(update_query.return_clause);
+    }
+
+    void visit(ast::Set& set_clause) override
+    {
+        accept(set_clause.set_list);
+    }
+
+    void visit(ast::SetValue& set_value) override
+    {
+        accept(set_value.value);
+    }
+
+    void visit(ast::SetElement& set_element) override
+    {
+        accept(set_element.accessor);
+        accept(set_element.set_value);
+    }
+
+    void visit(ast::SetList& set_list) override
+    {
+        accept(set_list.value);
+        if (set_list.next != nullptr)
+            accept(set_list.next);
+    }
+
     void visit(ast::Create& create) override
     {
         accept(create.pattern);