expression can be eather pattern expression or value expression

CMakeLists.txt

@@ -141,6 +141,7 @@ EXECUTE_PROCESS(
 
 # add main executable
 add_executable(memgraph src/memgraph.cpp)
+add_dependencies(memgraph cypher_lib)
 
 # link libraries
 target_link_libraries(memgraph Threads::Threads)

src/cypher/cypher.y

@@ -390,11 +390,11 @@ value_expr(E) ::= BOOL(V). {
     E = ast->create<ast::Boolean>(value);
 }
 
-// %type pattern_expr {ast::Expr*}
-// 
-// patter_expr(E) ::= pattern(P). {
-//     E = ast->create<ast::PatternExpr>(P);
-// }
+%type pattern_expr {ast::Expr*}
+
+pattern_expr(E) ::= pattern(P). {
+    E = ast->create<ast::PatternExpr>(P);
+}
 
 %type expr {ast::Expr*}
 
@@ -402,9 +402,9 @@ expr(E) ::= value_expr(V). {
     E = V;
 }
 
-// expr(E) ::= patter_expr(P). {
-//     E = P;
-// }
+expr(E) ::= pattern_expr(P). {
+    E = P;
+}
 
 //%type alias {ast::Alias*}
 //

src/cypher/debug/tree_print.hpp

@@ -106,6 +106,12 @@ public:
         Traverser::visit(pattern);
     }
 
+    void visit(ast::PatternExpr& pattern_expr) override
+    {
+        auto entry = printer.advance("Pattern Expression");
+        Traverser::visit(pattern_expr);
+    }
+
     void visit(ast::Node& node) override
     {
         auto entry = printer.advance("Node");

src/cypher/visitor/traverser.hpp

@@ -39,6 +39,11 @@ public:
         accept(pattern.next);
     }
 
+    void visit(ast::PatternExpr& pattern_expr) override
+    {
+        accept(pattern_expr.pattern);
+    }
+
     void visit(ast::Node& node) override
     {
         accept(node.idn);

tests/data/cypher_queries/complex/powerlinx_opportunities.cypher

@@ -1 +1 @@
-# MATCH (p:Personnel)-[:CREATED]->(o:Opportunity)-[:HAS_MATCH]->(c:Company {id: "321"}) RETURN (a:Account {id: "123"})-[:IS]->(p)
+MATCH (p:Personnel)-[:CREATED]->(o:Opportunity)-[:HAS_MATCH]->(c:Company {id: "321"}) RETURN (a:Account {id: "123"})-[:IS]->(p)