From c1e4676316e77634b6429995caa166aa1618bcc5 Mon Sep 17 00:00:00 2001
From: Teon Banek <teon.banek@memgraph.io>
Date: Fri, 9 Feb 2018 16:16:29 +0100
Subject: [PATCH] Add optional total_weight variable to wShortest grammar
Reviewers: florijan, msantl, buda
Reviewed By: msantl
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1187
---
src/query/frontend/ast/ast.hpp | 10 +++++++++-
.../frontend/ast/cypher_main_visitor.cpp | 19 +++++++++++++++++--
.../frontend/opencypher/grammar/Cypher.g4 | 6 +++---
.../frontend/semantic/symbol_generator.cpp | 8 ++++++++
tests/unit/cypher_main_visitor.cpp | 9 +++++++--
tests/unit/query_semantic.cpp | 6 ++++--
6 files changed, 48 insertions(+), 10 deletions(-)
diff --git a/src/query/frontend/ast/ast.hpp b/src/query/frontend/ast/ast.hpp
index e20312c95..7e567bece 100644
--- a/src/query/frontend/ast/ast.hpp
+++ b/src/query/frontend/ast/ast.hpp
@@ -1768,7 +1768,10 @@ class EdgeAtom : public PatternAtom {
cont = lower_bound_->Accept(visitor);
}
if (cont && upper_bound_) {
- upper_bound_->Accept(visitor);
+ cont = upper_bound_->Accept(visitor);
+ }
+ if (cont && total_weight_) {
+ total_weight_->Accept(visitor);
}
}
return visitor.PostVisit(*this);
@@ -1791,6 +1794,7 @@ class EdgeAtom : public PatternAtom {
};
edge_atom->filter_lambda_ = clone_lambda(filter_lambda_);
edge_atom->weight_lambda_ = clone_lambda(weight_lambda_);
+ edge_atom->total_weight_ = CloneOpt(total_weight_, storage);
return edge_atom;
}
@@ -1825,6 +1829,8 @@ class EdgeAtom : public PatternAtom {
/// It must have valid expressions and identifiers. In all other expand types,
/// it is empty.
Lambda weight_lambda_;
+ /// Variable where the total weight for weighted shortest path will be stored.
+ Identifier *total_weight_ = nullptr;
protected:
using PatternAtom::PatternAtom;
@@ -1866,6 +1872,7 @@ class EdgeAtom : public PatternAtom {
};
save_lambda(filter_lambda_);
save_lambda(weight_lambda_);
+ SavePointer(ar, total_weight_);
}
template <class TArchive>
@@ -1894,6 +1901,7 @@ class EdgeAtom : public PatternAtom {
};
load_lambda(filter_lambda_);
load_lambda(weight_lambda_);
+ LoadPointer(ar, total_weight_);
}
template <class TArchive>
diff --git a/src/query/frontend/ast/cypher_main_visitor.cpp b/src/query/frontend/ast/cypher_main_visitor.cpp
index b4e30be37..aba2efdc3 100644
--- a/src/query/frontend/ast/cypher_main_visitor.cpp
+++ b/src/query/frontend/ast/cypher_main_visitor.cpp
@@ -480,8 +480,8 @@ antlrcpp::Any CypherMainVisitor::visitRelationshipPattern(
return edge;
}
- if (relationshipDetail->variable()) {
- std::string variable = relationshipDetail->variable()->accept(this);
+ if (relationshipDetail->name) {
+ std::string variable = relationshipDetail->name->accept(this);
edge->identifier_ = storage_.Create<Identifier>(variable);
users_identifiers.insert(variable);
} else {
@@ -497,6 +497,10 @@ antlrcpp::Any CypherMainVisitor::visitRelationshipPattern(
auto relationshipLambdas = relationshipDetail->relationshipLambda();
if (variableExpansion) {
+ if (relationshipDetail->total_weight &&
+ edge->type_ != EdgeAtom::Type::WEIGHTED_SHORTEST_PATH)
+ throw SemanticException(
+ "Variable for total weight is allowed only in wShortest");
auto visit_lambda = [this](auto *lambda) {
EdgeAtom::Lambda edge_lambda;
std::string traversed_edge_variable =
@@ -510,6 +514,15 @@ antlrcpp::Any CypherMainVisitor::visitRelationshipPattern(
edge_lambda.expression = lambda->expression()->accept(this);
return edge_lambda;
};
+ auto visit_total_weight = [&]() {
+ if (relationshipDetail->total_weight) {
+ std::string total_weight_name =
+ relationshipDetail->total_weight->accept(this);
+ edge->total_weight_ = storage_.Create<Identifier>(total_weight_name);
+ } else {
+ anonymous_identifiers.push_back(&edge->total_weight_);
+ }
+ };
switch (relationshipLambdas.size()) {
case 0:
if (edge->type_ == EdgeAtom::Type::WEIGHTED_SHORTEST_PATH)
@@ -524,6 +537,7 @@ antlrcpp::Any CypherMainVisitor::visitRelationshipPattern(
// For wShortest, the first (and required) lambda is used for weight
// calculation.
edge->weight_lambda_ = visit_lambda(relationshipLambdas[0]);
+ visit_total_weight();
// Add mandatory inner variables for filter lambda.
anonymous_identifiers.push_back(&edge->filter_lambda_.inner_edge);
anonymous_identifiers.push_back(&edge->filter_lambda_.inner_node);
@@ -536,6 +550,7 @@ antlrcpp::Any CypherMainVisitor::visitRelationshipPattern(
if (edge->type_ != EdgeAtom::Type::WEIGHTED_SHORTEST_PATH)
throw SemanticException("Only one relationship lambda allowed");
edge->weight_lambda_ = visit_lambda(relationshipLambdas[0]);
+ visit_total_weight();
edge->filter_lambda_ = visit_lambda(relationshipLambdas[1]);
break;
default:
diff --git a/src/query/frontend/opencypher/grammar/Cypher.g4 b/src/query/frontend/opencypher/grammar/Cypher.g4
index 8737f4ecf..7d0a35137 100644
--- a/src/query/frontend/opencypher/grammar/Cypher.g4
+++ b/src/query/frontend/opencypher/grammar/Cypher.g4
@@ -123,9 +123,9 @@ relationshipPattern : ( leftArrowHead SP? dash SP? ( relationshipDetail )? SP? d
| ( dash SP? ( relationshipDetail )? SP? dash )
;
-relationshipDetail : '[' SP? ( variable SP? )? ( relationshipTypes SP? )? ( variableExpansion SP? )? properties SP? ']'
- | '[' SP? ( variable SP? )? ( relationshipTypes SP? )? ( variableExpansion SP? )? relationshipLambda SP? (relationshipLambda SP?)? ']'
- | '[' SP? ( variable SP? )? ( relationshipTypes SP? )? ( variableExpansion SP? )? ( (properties SP?) | (relationshipLambda SP?) )* ']';
+relationshipDetail : '[' SP? ( name=variable SP? )? ( relationshipTypes SP? )? ( variableExpansion SP? )? properties SP? ']'
+ | '[' SP? ( name=variable SP? )? ( relationshipTypes SP? )? ( variableExpansion SP? )? relationshipLambda SP? ( total_weight=variable SP? )? (relationshipLambda SP?)? ']'
+ | '[' SP? ( name=variable SP? )? ( relationshipTypes SP? )? ( variableExpansion SP? )? (properties SP?)* ( relationshipLambda SP? total_weight=variable SP? )? (relationshipLambda SP?)? ']';
relationshipLambda: '(' SP? traversed_edge=variable SP? ',' SP? traversed_node=variable SP? '|' SP? expression SP? ')';
diff --git a/src/query/frontend/semantic/symbol_generator.cpp b/src/query/frontend/semantic/symbol_generator.cpp
index 5413aedfe..2d5fa47fa 100644
--- a/src/query/frontend/semantic/symbol_generator.cpp
+++ b/src/query/frontend/semantic/symbol_generator.cpp
@@ -443,6 +443,14 @@ bool SymbolGenerator::PreVisit(EdgeAtom &edge_atom) {
scope_.in_pattern_atom_identifier = true;
edge_atom.identifier_->Accept(*this);
scope_.in_pattern_atom_identifier = false;
+ if (edge_atom.total_weight_) {
+ if (HasSymbol(edge_atom.total_weight_->name_)) {
+ throw RedeclareVariableError(edge_atom.total_weight_->name_);
+ }
+ symbol_table_[*edge_atom.total_weight_] = GetOrCreateSymbol(
+ edge_atom.total_weight_->name_, edge_atom.total_weight_->user_declared_,
+ Symbol::Type::Number);
+ }
return false;
}
diff --git a/tests/unit/cypher_main_visitor.cpp b/tests/unit/cypher_main_visitor.cpp
index ce237e40e..244e3ed6d 100644
--- a/tests/unit/cypher_main_visitor.cpp
+++ b/tests/unit/cypher_main_visitor.cpp
@@ -1632,8 +1632,8 @@ TYPED_TEST(CypherMainVisitorTest, MatchVariableLambdaSymbols) {
TYPED_TEST(CypherMainVisitorTest, MatchWShortestReturn) {
TypeParam ast_generator(
- "MATCH ()-[r:type1|type2 *wShortest 10 (we, wn | 42) (e, n | true)]->() "
- "RETURN r");
+ "MATCH ()-[r:type1|type2 *wShortest 10 (we, wn | 42) total_weight "
+ "(e, n | true)]->() RETURN r");
auto *query = ast_generator.query_;
ASSERT_TRUE(query->single_query_);
auto *single_query = query->single_query_;
@@ -1665,6 +1665,9 @@ TYPED_TEST(CypherMainVisitorTest, MatchWShortestReturn) {
EXPECT_EQ(shortest->weight_lambda_.inner_node->name_, "wn");
EXPECT_TRUE(shortest->weight_lambda_.inner_node->user_declared_);
CheckLiteral(ast_generator.context_, shortest->weight_lambda_.expression, 42);
+ ASSERT_TRUE(shortest->total_weight_);
+ EXPECT_EQ(shortest->total_weight_->name_, "total_weight");
+ EXPECT_TRUE(shortest->total_weight_->user_declared_);
}
TYPED_TEST(CypherMainVisitorTest, MatchWShortestNoFilterReturn) {
@@ -1699,6 +1702,8 @@ TYPED_TEST(CypherMainVisitorTest, MatchWShortestNoFilterReturn) {
EXPECT_EQ(shortest->weight_lambda_.inner_node->name_, "wn");
EXPECT_TRUE(shortest->weight_lambda_.inner_node->user_declared_);
CheckLiteral(ast_generator.context_, shortest->weight_lambda_.expression, 42);
+ ASSERT_TRUE(shortest->total_weight_);
+ EXPECT_FALSE(shortest->total_weight_->user_declared_);
}
diff --git a/tests/unit/query_semantic.cpp b/tests/unit/query_semantic.cpp
index b0581bc53..09839c216 100644
--- a/tests/unit/query_semantic.cpp
+++ b/tests/unit/query_semantic.cpp
@@ -944,6 +944,7 @@ TEST_F(TestSymbolGenerator, MatchWShortestReturn) {
shortest->weight_lambda_.inner_edge = IDENT("r");
shortest->weight_lambda_.inner_node = IDENT("n");
shortest->weight_lambda_.expression = r_weight;
+ shortest->total_weight_ = IDENT("total_weight");
}
{
shortest->filter_lambda_.inner_edge = IDENT("r");
@@ -954,8 +955,9 @@ TEST_F(TestSymbolGenerator, MatchWShortestReturn) {
auto *query = QUERY(SINGLE_QUERY(MATCH(PATTERN(node_n, shortest, NODE("m"))),
RETURN(ret_r, AS("r"))));
query->Accept(symbol_generator);
- // Symbols for pattern, `n`, `[r]`, (`r|`, `n|`)x2, `m` and `AS r`.
- EXPECT_EQ(symbol_table.max_position(), 9);
+ // Symbols for pattern, `n`, `[r]`, `total_weight`, (`r|`, `n|`)x2, `m` and
+ // `AS r`.
+ EXPECT_EQ(symbol_table.max_position(), 10);
EXPECT_EQ(symbol_table.at(*ret_r), symbol_table.at(*shortest->identifier_));
EXPECT_NE(symbol_table.at(*ret_r),
symbol_table.at(*shortest->weight_lambda_.inner_edge));