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Add optional total_weight variable to wShortest grammar

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Reviewers: florijan, msantl, buda

Reviewed By: msantl

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D1187
This commit is contained in:
Teon Banek 2018-02-09 16:16:29 +01:00
parent fc2703833c
commit c1e4676316
6 changed files with 48 additions and 10 deletions

10
src/query/frontend/ast/ast.hpp
View File

@ -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>

19
src/query/frontend/ast/cypher_main_visitor.cpp
View File

@ -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:

6
src/query/frontend/opencypher/grammar/Cypher.g4
View File

@ -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? ')';

8
src/query/frontend/semantic/symbol_generator.cpp
View File

@ -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;
}

9
tests/unit/cypher_main_visitor.cpp
View File

@ -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_);
}

6
tests/unit/query_semantic.cpp
View File

@ -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));