ARROW-46531: [C++] Add type_singleton utility function and corresponding tests

Author: harshkumar-2005

cpp/src/arrow/type_test.cc

@@ -32,10 +32,12 @@
 #include "arrow/memory_pool.h"
 #include "arrow/table.h"
 #include "arrow/testing/gtest_util.h"
+#include "arrow/testing/matchers.h"
 #include "arrow/testing/random.h"
 #include "arrow/testing/util.h"
 #include "arrow/type.h"
 #include "arrow/type_traits.h"
+#include "arrow/util/logging.h"
 #include "arrow/util/checked_cast.h"
 #include "arrow/util/key_value_metadata.h"
 
@@ -49,6 +51,66 @@ TEST(TestTypeId, AllTypeIds) {
   ASSERT_EQ(static_cast<int>(all_ids.size()), Type::MAX_ID);
 }
 
+TEST(TestTypeSingleton, ParameterFreeTypes) {
+  // Test successful cases - parameter-free types
+  std::vector<std::pair<Type::type, std::shared_ptr<DataType>>> cases = {
+      {Type::NA, null()},
+      {Type::BOOL, boolean()},
+      {Type::INT8, int8()},
+      {Type::INT16, int16()},
+      {Type::INT32, int32()},
+      {Type::INT64, int64()},
+      {Type::UINT8, uint8()},
+      {Type::UINT16, uint16()},
+      {Type::UINT32, uint32()},
+      {Type::UINT64, uint64()},
+      {Type::HALF_FLOAT, float16()},
+      {Type::FLOAT, float32()},
+      {Type::DOUBLE, float64()},
+      {Type::STRING, utf8()},
+      {Type::BINARY, binary()},
+      {Type::LARGE_STRING, large_utf8()},
+      {Type::LARGE_BINARY, large_binary()},
+      {Type::DATE32, date32()},
+  };
+
+  for (const auto& test_case : cases) {
+    SCOPED_TRACE("Testing type: " + std::to_string(static_cast<int>(test_case.first)));
+    auto result = type_singleton(test_case.first);
+    ASSERT_OK_AND_ASSIGN(auto type, result);
+    ASSERT_TRUE(type->Equals(*test_case.second))
+        << "Failed on type " << test_case.first << ". Expected "
+        << test_case.second->ToString() << " but got " << type->ToString();
+  }
+}
+
+TEST(TestTypeSingleton, ParameterizedTypes) {
+  // Test error cases - parameterized types
+  std::vector<Type::type> parameterized_types = {
+      Type::TIMESTAMP,    Type::TIME32,           Type::TIME64,
+      Type::DURATION,     Type::FIXED_SIZE_BINARY, Type::DECIMAL128,
+      Type::LIST,         Type::LARGE_LIST,       Type::FIXED_SIZE_LIST,
+      Type::STRUCT,       Type::DICTIONARY,       Type::MAP,
+      Type::EXTENSION
+  };
+
+  for (const auto type_id : parameterized_types) {
+    SCOPED_TRACE("Testing type: " + std::to_string(static_cast<int>(type_id)));
+    auto result = type_singleton(type_id);
+    ASSERT_FALSE(result.ok());
+    const auto& status = result.status();
+    EXPECT_THAT(status.message(), testing::HasSubstr("is not a parameter-free singleton type"));
+  }
+}
+
+TEST(TestTypeSingleton, InvalidType) {
+  // Test with an invalid type ID
+  auto result = type_singleton(static_cast<Type::type>(9999));
+  ASSERT_FALSE(result.ok());
+  const auto& status = result.status();
+  EXPECT_THAT(status.message(), testing::HasSubstr("requires parameters or is not supported"));
+}
+
 template <typename ReprFunc>
 void CheckTypeIdReprs(ReprFunc&& repr_func, bool expect_uppercase) {
   std::unordered_set<std::string> unique_reprs;

cpp/src/arrow/type_traits.cc

@@ -17,10 +17,73 @@
 
 #include "arrow/type_traits.h"
 
+#include "arrow/result.h"
+#include "arrow/status.h"
+#include "arrow/type.h"
 #include "arrow/util/logging_internal.h"
 
 namespace arrow {
 
+Result<std::shared_ptr<DataType>> type_singleton(Type::type id) {
+  switch (id) {
+    case Type::NA:
+      return null();
+    case Type::BOOL:
+      return boolean();
+    case Type::INT8:
+      return int8();
+    case Type::INT16:
+      return int16();
+    case Type::INT32:
+      return int32();
+    case Type::INT64:
+      return int64();
+    case Type::UINT8:
+      return uint8();
+    case Type::UINT16:
+      return uint16();
+    case Type::UINT32:
+      return uint32();
+    case Type::UINT64:
+      return uint64();
+    case Type::HALF_FLOAT:
+      return float16();
+    case Type::FLOAT:
+      return float32();
+    case Type::DOUBLE:
+      return float64();
+    case Type::STRING:
+      return utf8();
+    case Type::BINARY:
+      return binary();
+    case Type::LARGE_STRING:
+      return large_utf8();
+    case Type::LARGE_BINARY:
+      return large_binary();
+    case Type::DATE32:
+      return date32();
+
+    // Explicitly handle known parameterized types
+    case Type::TIMESTAMP:
+    case Type::TIME32:
+    case Type::TIME64:
+    case Type::DURATION:
+    case Type::FIXED_SIZE_BINARY:
+    case Type::DECIMAL128:
+    case Type::LIST:
+    case Type::LARGE_LIST:
+    case Type::FIXED_SIZE_LIST:
+    case Type::STRUCT:
+    case Type::DICTIONARY:
+    case Type::MAP:
+    case Type::EXTENSION:
+      return Status::Invalid("Type ", id, " is not a parameter-free singleton type.");
+
+    default:
+      return Status::Invalid("Type ", id, " requires parameters or is not supported");
+  }
+}
+
 int RequiredValueAlignmentForBuffer(Type::type type_id, int buffer_index) {
   if (buffer_index == 2 && type_id == Type::DENSE_UNION) {
     // A dense union array is the only array (so far) that requires alignment

cpp/src/arrow/type_traits.h

@@ -22,8 +22,10 @@
 #include <type_traits>
 #include <vector>
 
+#include "arrow/result.h"
 #include "arrow/type.h"
 #include "arrow/util/bit_util.h"
+#include "arrow/util/macros.h"
 
 namespace arrow {
 
@@ -596,6 +598,19 @@ struct TypeTraits<ExtensionType> {
 };
 /// @}
 
+/// \brief Create a data type instance from a type ID for parameter-free types
+///
+/// This function creates a data type instance for types that don't require
+/// additional parameters (where TypeTraits<T>::is_parameter_free is true).
+/// For types that require parameters (like TimestampType or ListType),
+/// this function will return an error.
+///
+/// \param[in] id The type ID to create a type instance for
+/// \return Result with a shared pointer to the created DataType instance,
+///         or an error if the type requires parameters
+ARROW_EXPORT
+Result<std::shared_ptr<DataType>> type_singleton(Type::type id);
+
 namespace internal {
 
 template <typename... Ts>