From 5057eeb7dfb41c6eb0cbb459cb455bda77c5fe66 Mon Sep 17 00:00:00 2001
From: Cheng Xuntao <7731943+xtcyclist@users.noreply.github.com>
Date: Thu, 8 Dec 2022 13:31:50 +0800
Subject: [PATCH] Allow usage of aliases defined in previous matches. (#5021)

* allow usage of aliases defined in previous matches.

* update tck

* add a tck

* fix tck format
---
 src/graph/validator/MatchValidator.cpp |  9 ++++++---
 src/parser/Clauses.h                   | 22 +++++++++++++++++++-
 tests/tck/features/match/With.feature  | 28 +++++++++++++++++++++++++-
 3 files changed, 54 insertions(+), 5 deletions(-)

diff --git a/src/graph/validator/MatchValidator.cpp b/src/graph/validator/MatchValidator.cpp
index eb5d998a374..8a359b7f2f1 100644
--- a/src/graph/validator/MatchValidator.cpp
+++ b/src/graph/validator/MatchValidator.cpp
@@ -379,7 +379,7 @@ Status MatchValidator::buildColumnsForAllNamedAliases(const std::vector<QueryPar
     switch (boundary->kind) {
       case CypherClauseKind::kUnwind: {
         auto unwindCtx = static_cast<const UnwindClauseContext *>(boundary.get());
-        columns->addColumn(makeColumn(unwindCtx->alias));
+        columns->addColumn(makeColumn(unwindCtx->alias), true);
         break;
       }
       case CypherClauseKind::kWith: {
@@ -390,7 +390,7 @@ Status MatchValidator::buildColumnsForAllNamedAliases(const std::vector<QueryPar
         }
         for (auto &col : yieldColumns->columns()) {
           if (!col->alias().empty()) {
-            columns->addColumn(makeColumn(col->alias()));
+            columns->addColumn(makeColumn(col->alias()), true);
           }
         }
         break;
@@ -584,7 +584,10 @@ Status MatchValidator::validateWith(const WithClause *with,
       auto found = withClauseCtx.yield->aliasesAvailable.find(label);
       DCHECK(found != withClauseCtx.yield->aliasesAvailable.end());
       if (!withClauseCtx.aliasesGenerated.emplace(col->alias(), found->second).second) {
-        return Status::SemanticError("`%s': Redefined alias", col->alias().c_str());
+        auto columnFound = withClauseCtx.yield->yieldColumns->find(col->alias());
+        if (!(columnFound != nullptr && columnFound->isMatched())) {
+          return Status::SemanticError("`%s': Redefined alias", col->alias().c_str());
+        }
       }
     } else {
       if (!withClauseCtx.aliasesGenerated.emplace(col->alias(), aliasType).second) {
diff --git a/src/parser/Clauses.h b/src/parser/Clauses.h
index fd62eb20418..0d275996028 100644
--- a/src/parser/Clauses.h
+++ b/src/parser/Clauses.h
@@ -257,6 +257,7 @@ class YieldColumn final {
   explicit YieldColumn(Expression *expr, const std::string &alias = "") {
     expr_ = expr;
     alias_ = alias;
+    isMatched_ = false;
   }
 
   std::unique_ptr<YieldColumn> clone() const {
@@ -285,9 +286,18 @@ class YieldColumn final {
 
   std::string toString() const;
 
+  void setMatched(bool isMatched) {
+    isMatched_ = isMatched;
+  }
+
+  bool isMatched() const {
+    return isMatched_;
+  }
+
  private:
   Expression *expr_{nullptr};
   std::string alias_;
+  bool isMatched_;
 };
 
 bool operator==(const YieldColumn &l, const YieldColumn &r);
@@ -297,8 +307,9 @@ inline bool operator!=(const YieldColumn &l, const YieldColumn &r) {
 
 class YieldColumns final {
  public:
-  void addColumn(YieldColumn *field) {
+  void addColumn(YieldColumn *field, bool isMatched = false) {
     columns_.emplace_back(field);
+    field->setMatched(isMatched);
   }
 
   std::vector<YieldColumn *> columns() const {
@@ -346,6 +357,15 @@ class YieldColumns final {
 
   bool hasAgg() const;
 
+  YieldColumn *find(const std::string &name) const {
+    for (auto &col : columns_) {
+      if (name.compare(col->name()) == 0) {
+        return col.get();
+      }
+    }
+    return nullptr;
+  }
+
  private:
   std::vector<std::unique_ptr<YieldColumn>> columns_;
 };
diff --git a/tests/tck/features/match/With.feature b/tests/tck/features/match/With.feature
index 895853de8ba..7637c5b374f 100644
--- a/tests/tck/features/match/With.feature
+++ b/tests/tck/features/match/With.feature
@@ -378,7 +378,7 @@ Feature: With clause
   Scenario: with wildcard after unwind
     When executing query:
       """
-      match p = (v0)-[e0]->(v1) where id(v0) in ["Tim Duncan"] unwind v0 as uv0 with * return e0 limit 5;
+      match p = (v0)-[e0]->(v1) where id(v0) in ["Tim Duncan"] unwind v0 as uv0 with * return e0;
       """
     Then the result should be, in any order:
       | e0                                                                                  |
@@ -387,3 +387,29 @@ Feature: With clause
       | [:teammate "Tim Duncan"->"Tony Parker" @0 {end_year: 2016, start_year: 2001}]       |
       | [:like "Tim Duncan"->"Tony Parker" @0 {likeness: 95}]                               |
       | [:teammate "Tim Duncan"->"Danny Green" @0 {end_year: 2016, start_year: 2010}]       |
+      | [:teammate "Tim Duncan"->"Manu Ginobili" @0 {end_year: 2016, start_year: 2002}]     |
+      | [:like "Tim Duncan"->"Manu Ginobili" @0 {likeness: 95}]                             |
+
+  Scenario: with wildcard after multiple matches
+    When executing query:
+      """
+      match (v0:player)--(v1:team) where v1.team.name == "Spurs" and v0.player.name == "Tim Duncan"
+      match (v:player) where v.player.name != "Tim Duncan" with v0 where v0.player.age > 0
+      match (v0:player)
+      with *
+      return count(v0)
+      """
+    Then the result should be, in order:
+      | count(v0) |
+      | 51        |
+    When executing query:
+      """
+      match (v:player)
+      with v AS p
+      match (p)
+      with p AS v
+      match (v)
+      with *
+      return count (p)
+      """
+    Then a SemanticError should be raised at runtime:  Alias used but not defined: `p'