F: Add check for nonsensical emptyset uses

ccl/rslang/include/ccl/rslang/RSErrorCodes.hpp

@@ -46,6 +46,7 @@ enum class SemanticEID : uint32_t {
   invalidBinding = 0x8814,           // Количество переменных в кортеже не соответствует размерности декартова произведения
   localOutOfScope = 0x8815,         // Использование имени вне области видимости
   invalidElementPredicate = 0x8816,  // Несоответствие типов для проверки принадлежности
+  invalidEmptySetUsage = 0x8817,  // Бессмысленное использование пустого множества
   invalidArgsArity = 0x8818,       // Некорректное количество аргументов терм-функции
   invalidArgumentType = 0x8819,     // Типизация аргумента не совпадает с объявленной
   globalStructure = 0x881C,         // Родовая структура должна быть ступенью

ccl/rslang/include/ccl/rslang/TypeAuditor.h

@@ -38,6 +38,8 @@ class TypeAuditor final : public ASTVisitor<TypeAuditor> {
   friend class SyntaxTree::Cursor;
   friend class ASTVisitor<TypeAuditor>;
 
+  using DeboolCallback = std::function<void(const std::string&)>;
+
   static constexpr auto typeDeductionDepth = 5;
 
   struct LocalData  {
@@ -85,7 +87,7 @@ protected:
   bool ViLocal(Cursor iter);
   bool ViInteger(Cursor /*iter*/) { return SetCurrent(Typification::Integer()); }
   bool ViIntegerSet(Cursor /*iter*/) { return SetCurrent(Typification::Integer().Bool()); }
-  bool ViEmptySet(Cursor /*iter*/);
+  bool ViEmptySet(Cursor iter);
 
   bool ViTupleDeclaration(Cursor iter);
   bool ViEnumDeclaration(Cursor iter) { return VisitAllAndSetCurrent(iter, LogicT{}); }
@@ -132,6 +134,7 @@ private:
 
   [[nodiscard]] std::optional<ExpressionType> ChildType(Cursor iter, Index index);
   [[nodiscard]] std::optional<Typification> ChildTypeDebool(Cursor iter, Index index, SemanticEID eid);
+  [[nodiscard]] std::optional<Typification> ChildTypeDebool(Cursor iter, Index index, DeboolCallback onError);
 
   void OnError(SemanticEID eid, StrPos position);
   void OnError(SemanticEID eid, StrPos position, std::string param);

ccl/rslang/src/TypeAuditor.cpp

@@ -469,7 +469,23 @@ bool TypeAuditor::ViLocal(Cursor iter) {
   }
 }
 
-bool TypeAuditor::ViEmptySet(Cursor /*iter*/) {
+bool TypeAuditor::ViEmptySet(Cursor iter) {
+  static const std::vector<TokenID> invalidParents{
+    TokenID::CARD,
+    TokenID::DEBOOL,
+    TokenID::UNION,
+    TokenID::INTERSECTION,
+    TokenID::SET_MINUS,
+    TokenID::SYMMINUS,
+    TokenID::DECART,
+    TokenID::REDUCE,
+    TokenID::BIGPR,
+    TokenID::SMALLPR
+  };
+  if (std::find(invalidParents.begin(), invalidParents.end(), iter.Parent().id) != invalidParents.end()) {
+    OnError(SemanticEID::invalidEmptySetUsage, iter->pos.start);
+    return false;
+  }
   return SetCurrent(Typification::EmptySet());
 }
 
@@ -862,7 +878,11 @@ bool TypeAuditor::ViSetexprBinary(Cursor iter) {
 
 bool TypeAuditor::ViProjectSet(Cursor iter) {
   // T(Pri(a)) = B(Pi(D(T(a))))
-  const auto maybeArgument = ChildTypeDebool(iter, 0, SemanticEID::invalidProjectionSet);
+  const auto maybeArgument = ChildTypeDebool(iter, 0,
+    [iter, this](const std::string& typeString) {
+      this->OnError(SemanticEID::invalidProjectionSet, iter(0).pos.start, { iter->ToString(), typeString });
+    }
+  );
   if (!maybeArgument.has_value()) {
     return false;
   }
@@ -1064,6 +1084,14 @@ std::optional<ExpressionType> TypeAuditor::ChildType(Cursor iter, const Index in
 }
 
 std::optional<Typification> TypeAuditor::ChildTypeDebool(Cursor iter, const Index index, const SemanticEID eid) {
+  return ChildTypeDebool(iter, index, 
+    [iter, eid, index, this](const std::string& typeString) {
+      this->OnError(eid, iter(index).pos.start, typeString);
+    }
+  );
+}
+
+std::optional<Typification> TypeAuditor::ChildTypeDebool(Cursor iter, const Index index, DeboolCallback onError) {
   const auto maybeResult = ChildType(iter, index);
   if (!maybeResult.has_value() || !std::holds_alternative<Typification>(maybeResult.value())) {
     return std::nullopt;
@@ -1073,11 +1101,7 @@ std::optional<Typification> TypeAuditor::ChildTypeDebool(Cursor iter, const Inde
     return result;
   }
   if (!result.IsCollection()) {
-    OnError(
-      eid,
-      iter(index).pos.start,
-      ToString(maybeResult.value())
-    );
+    onError(ToString(maybeResult.value()));
     return std::nullopt;
   }
   return result.B().Base();

ccl/rslang/test/src/testTypeAuditor.cpp

@@ -181,6 +181,7 @@ TEST_F(UTTypeAuditor, NumericErrors) {
   ExpectError(R"(card(debool(X1)))", SemanticEID::invalidCard, 5);
   ExpectError(R"(card(S4))", SemanticEID::invalidCard, 5);
   ExpectError(R"(card(1))", SemanticEID::invalidCard, 5);
+  ExpectError(R"(card({}))", SemanticEID::invalidEmptySetUsage, 5);
   ExpectError(R"(card((1,2)))", SemanticEID::invalidCard, 5);
 
   ExpectError(R"(debool(X1) \plus 1)", SemanticEID::arithmeticNotSupported, 0);
@@ -328,9 +329,6 @@ TEST_F(UTTypeAuditor, TypedOperationsCorrect) {
   SetupConstants();
 
   ExpectTypification(R"(X1 \union X1)", "B(X1)"_t);
-  ExpectTypification(R"({} \union {})", "B(R0)"_t);
-  ExpectTypification(R"(X1 \union {})", "B(X1)"_t);
-  ExpectTypification(R"({} \union X1)", "B(X1)"_t);
   ExpectTypification(R"(X1 \setminus X1)", "B(X1)"_t);
   ExpectTypification(R"(X1 \intersect X1)", "B(X1)"_t);
   ExpectTypification(R"(X1 \symmdiff X1)", "B(X1)"_t);
@@ -344,14 +342,12 @@ TEST_F(UTTypeAuditor, TypedOperationsCorrect) {
   ExpectTypification(R"(B(X1))", "BB(X1)"_t);
   ExpectTypification(R"(X1*X1)", "B(X1*X1)"_t);
   ExpectTypification(R"(Pr1(S1))", "B(X1)"_t);
-  ExpectTypification(R"(Pr1({}))", "B(R0)"_t);
   ExpectTypification(R"(Fi1[X1](S1))", "B(X1*X1)"_t);
   ExpectTypification(R"(Fi1,2[X1, X1](S1))", "B(X1*X1)"_t);
   ExpectTypification(R"(Fi1,2[X1 * X1](S1))", "B(X1*X1)"_t);
   ExpectTypification(R"(Fi1[{1,2,3}](Z*X1))", "B(Z*X1)"_t);
   ExpectTypification(R"(Fi1[{1,2,3}](C1*X1))", "B(C1*X1)"_t);
   ExpectTypification(R"(Pr1,2(S1))", "B(X1*X1)"_t);
-  ExpectTypification(R"(Pr1,2({}))", "B(R0)"_t);
   ExpectTypification(R"(bool(X1))", "BB(X1)"_t);
   ExpectTypification(R"(debool({X1}))", "B(X1)"_t);
   ExpectTypification(R"(red(S2))", "B(X1)"_t);
@@ -361,11 +357,14 @@ TEST_F(UTTypeAuditor, TypedOperationsErrors) {
   SetupConstants();
 
   ExpectError(R"(X1 \union S2)", SemanticEID::typesNotEqual, 10);
+  ExpectError(R"(X1 \union {})", SemanticEID::invalidEmptySetUsage, 10);
   ExpectError(R"(S2 \union X1)", SemanticEID::typesNotEqual, 10);
 
   ExpectError(R"(Pr1(X1))", SemanticEID::invalidProjectionSet, 4);
+  ExpectError(R"(Pr1({}))", SemanticEID::invalidEmptySetUsage, 4);
   ExpectError(R"(Pr3(S1))", SemanticEID::invalidProjectionSet, 4);
   ExpectError(R"(pr1(debool(X1)))", SemanticEID::invalidProjectionTuple, 4);
+  ExpectError(R"(pr1({}))", SemanticEID::invalidEmptySetUsage, 4);
   ExpectError(R"(Fi1[X1](B(X1)))", SemanticEID::invalidFilterArgumentType, 8);
   ExpectError(R"(Fi1[1](B(X1)))", SemanticEID::invalidFilterArgumentType, 7);
   ExpectError(R"(Fi1[S4](B(X1)))", SemanticEID::invalidFilterArgumentType, 8);
@@ -377,6 +376,7 @@ TEST_F(UTTypeAuditor, TypedOperationsErrors) {
   ExpectError(R"(\A a \in X1 Fi1[a](B(X1)*X1) \eq X1)", SemanticEID::typesNotEqual, 16);
   ExpectError(R"(\A a \in X1*X1 Fi1[a](B(X1)*X1) \eq X1)", SemanticEID::typesNotEqual, 19);
   ExpectError(R"(red(X1))", SemanticEID::invalidReduce, 5);
+  ExpectError(R"(red({}))", SemanticEID::invalidEmptySetUsage, 4);
 
   ExpectError(R"(\A a \in X1 B(a) \eq X1)", SemanticEID::invalidBoolean, 14);
   ExpectError(R"(\A a \in S1 B(a) \eq X1)", SemanticEID::invalidBoolean, 14);

pyconcept/CHANGELOG.md

@@ -19,6 +19,12 @@ Here we write upgrading notes. Make them as straightforward as possible.
 
 ### Fixed
 
+## [0.1.9] - 2024-09-25
+
+### Added
+
+- Add new rule to prevent unreasonable use of emptyset
+
 ## [0.1.8] - 2024-09-22
 
 ### Fixed

pyconcept/VERSION

@@ -1 +1 @@
-0.1.8
+0.1.9