Initial: replacing hardcoded toString for enums with magic_enum

.gitmodules

@@ -246,3 +246,6 @@
 [submodule "contrib/bzip2"]
 	path = contrib/bzip2
 	url = https://github.com/ClickHouse-Extras/bzip2.git
+[submodule "contrib/magic_enum"]
+	path = contrib/magic_enum
+	url = https://github.com/Neargye/magic_enum

base/common/EnumReflection.h

@@ -0,0 +1,32 @@
+#pragma once
+
+#include <type_traits>
+#include <fmt/format.h>
+#include <../../contrib/magic_enum/include/magic_enum.hpp> //FIXME
+
+// Can't name concept is_enum as is would conflict with type trait
+template <class T> concept type_is_enum = std::is_enum_v<T>;
+
+// Enable printing enum values as strings via fmt + magic_enum
+template <type_is_enum T>
+struct fmt::formatter<T> : fmt::formatter<std::string_view> {
+    constexpr auto format(T enum_value, auto& format_context) {
+        return formatter<string_view>::format(
+            magic_enum::enum_name(enum_value), format_context);
+    }
+};
+
+namespace DB
+{
+
+/**
+ * Some enums have multiple-word values like FLUSH_DICT. However, we should parse user input like FLUSH DICT.
+ * magic_enum::enum_names returns names with underscore, so we have to replace underscore with space.
+ */
+std::string UnderscoreToSpace(std::string_view str)
+{
+    std::string out(str.data(), str.size());
+    std::replace(out.begin(), out.end(), '_', ' ');
+    return out;
+}
+}

contrib/CMakeLists.txt

@@ -32,6 +32,8 @@ endif()
 
 set_property(DIRECTORY PROPERTY EXCLUDE_FROM_ALL 1)
 
+include_directories("${CMAKE_SOURCE_DIR}/contrib/magic_enum/include")
+
 add_subdirectory (abseil-cpp-cmake)
 add_subdirectory (boost-cmake)
 add_subdirectory (cctz-cmake)

contrib/magic_enum

@@ -0,0 +1 @@
+Subproject commit 38f86e4d093cfc9034a140d37de2168e3951bef3

src/Columns/ColumnAggregateFunction.cpp

@@ -506,8 +506,9 @@ static void pushBackAndCreateState(ColumnAggregateFunction::Container & data, Ar
 void ColumnAggregateFunction::insert(const Field & x)
 {
     if (x.getType() != Field::Types::AggregateFunctionState)
-        throw Exception(String("Inserting field of type ") + x.getTypeName() + " into ColumnAggregateFunction. "
-                        "Expected " + Field::Types::toString(Field::Types::AggregateFunctionState), ErrorCodes::LOGICAL_ERROR);
+        throw Exception(ErrorCodes::LOGICAL_ERROR,
+            "Inserting field of type {} into ColumnAggregateFunction. Expected {}",
+            x.getTypeName(), Field::Types::AggregateFunctionState);
 
     const auto & field_name = x.get<const AggregateFunctionStateData &>().name;
     if (type_string != field_name)

src/Common/ExternalLoaderStatus.cpp

@@ -1,39 +0,0 @@
-#include <Common/ExternalLoaderStatus.h>
-
-namespace DB
-{
-    String toString(ExternalLoaderStatus status)
-    {
-        using Status = ExternalLoaderStatus;
-        switch (status)
-        {
-            case Status::NOT_LOADED: return "NOT_LOADED";
-            case Status::LOADED: return "LOADED";
-            case Status::FAILED: return "FAILED";
-            case Status::LOADING: return "LOADING";
-            case Status::FAILED_AND_RELOADING: return "FAILED_AND_RELOADING";
-            case Status::LOADED_AND_RELOADING: return "LOADED_AND_RELOADING";
-            case Status::NOT_EXIST: return "NOT_EXIST";
-        }
-    __builtin_unreachable();
-    }
-
-    std::vector<std::pair<String, Int8>> getStatusEnumAllPossibleValues()
-    {
-        using Status = ExternalLoaderStatus;
-        return std::vector<std::pair<String, Int8>>{
-            {toString(Status::NOT_LOADED), static_cast<Int8>(Status::NOT_LOADED)},
-            {toString(Status::LOADED), static_cast<Int8>(Status::LOADED)},
-            {toString(Status::FAILED), static_cast<Int8>(Status::FAILED)},
-            {toString(Status::LOADING), static_cast<Int8>(Status::LOADING)},
-            {toString(Status::LOADED_AND_RELOADING), static_cast<Int8>(Status::LOADED_AND_RELOADING)},
-            {toString(Status::FAILED_AND_RELOADING), static_cast<Int8>(Status::FAILED_AND_RELOADING)},
-            {toString(Status::NOT_EXIST), static_cast<Int8>(Status::NOT_EXIST)},
-        };
-    }
-
-    std::ostream & operator<<(std::ostream & out, ExternalLoaderStatus status)
-    {
-        return out << toString(status);
-    }
-}

src/Common/ExternalLoaderStatus.h

@@ -4,10 +4,11 @@
 #include <utility>
 #include <ostream>
 #include <common/types.h>
+#include <common/EnumReflection.h>
 
 namespace DB
 {
-    enum class ExternalLoaderStatus
+    enum class ExternalLoaderStatus : Int8
     {
         NOT_LOADED, /// Object hasn't been tried to load. This is an initial state.
         LOADED, /// Object has been loaded successfully.
@@ -18,7 +19,14 @@ namespace DB
         NOT_EXIST, /// Object with this name wasn't found in the configuration.
     };
 
-    String toString(ExternalLoaderStatus status);
-    std::vector<std::pair<String, Int8>> getStatusEnumAllPossibleValues();
-    std::ostream & operator<<(std::ostream & out, ExternalLoaderStatus status);
+    std::vector<std::pair<String, Int8>> getStatusEnumAllPossibleValues()
+    {
+        std::vector<std::pair<String, Int8>> out;
+        out.reserve(magic_enum::enum_count<ExternalLoaderStatus>());
+
+        for (const auto & [value, str] : magic_enum::enum_entries<ExternalLoaderStatus>())
+            out.emplace_back(str, value);
+
+        return out;
+    }
 }

src/Common/IntervalKind.cpp

@@ -9,23 +9,6 @@ namespace ErrorCodes
     extern const int SYNTAX_ERROR;
 }
 
-const char * IntervalKind::toString() const
-{
-    switch (kind)
-    {
-        case IntervalKind::Second: return "Second";
-        case IntervalKind::Minute: return "Minute";
-        case IntervalKind::Hour: return "Hour";
-        case IntervalKind::Day: return "Day";
-        case IntervalKind::Week: return "Week";
-        case IntervalKind::Month: return "Month";
-        case IntervalKind::Quarter: return "Quarter";
-        case IntervalKind::Year: return "Year";
-    }
-    __builtin_unreachable();
-}
-
-
 Int32 IntervalKind::toAvgSeconds() const
 {
     switch (kind)

src/Common/IntervalKind.h

@@ -1,7 +1,7 @@
 #pragma once
 
 #include <common/types.h>
-
+#include <common/EnumReflection.h>
 
 namespace DB
 {
@@ -24,7 +24,7 @@ struct IntervalKind
     IntervalKind(Kind kind_ = Second) : kind(kind_) {}
     operator Kind() const { return kind; }
 
-    const char * toString() const;
+    constexpr std::string_view toString() const { return magic_enum::enum_name(kind); }
 
     /// Returns number of seconds in one interval.
     /// For `Month`, `Quarter` and `Year` the function returns an average number of seconds.

src/Common/JSONBuilder.h

@@ -33,7 +33,7 @@ using ItemPtr = std::unique_ptr<IItem>;
 class JSONString : public IItem
 {
 public:
-    explicit JSONString(std::string value_) : value(std::move(value_)) {}
+    JSONString(std::string_view value_) : value(value_) {}
     void format(const FormatSettings & settings, FormatContext & context) override;
 
 private:
@@ -97,6 +97,7 @@ public:
     void add(std::string key, ItemPtr value) { values.emplace_back(Pair{.key = std::move(key), .value = std::move(value)}); }
     void add(std::string key, std::string value) { add(std::move(key), std::make_unique<JSONString>(std::move(value))); }
     void add(std::string key, const char * value) { add(std::move(key), std::make_unique<JSONString>(value)); }
+    void add(std::string key, std::string_view value) { add(std::move(key), std::make_unique<JSONString>(value)); }
     void add(std::string key, bool value) { add(std::move(key), std::make_unique<JSONBool>(std::move(value))); }
 
     template <typename T, std::enable_if_t<std::is_arithmetic<T>::value, bool> = true>

src/Core/Field.h

@@ -15,7 +15,6 @@
 #include <common/DayNum.h>
 #include <common/strong_typedef.h>
 
-
 namespace DB
 {
 
@@ -283,33 +282,6 @@ public:
             Map = 26,
             UUID = 27,
         };
-
-        static const char * toString(Which which)
-        {
-            switch (which)
-            {
-                case Null:    return "Null";
-                case UInt64:  return "UInt64";
-                case UInt128: return "UInt128";
-                case UInt256: return "UInt256";
-                case Int64:   return "Int64";
-                case Int128:  return "Int128";
-                case Int256:  return "Int256";
-                case UUID:    return "UUID";
-                case Float64: return "Float64";
-                case String:  return "String";
-                case Array:   return "Array";
-                case Tuple:   return "Tuple";
-                case Map:     return "Map";
-                case Decimal32:  return "Decimal32";
-                case Decimal64:  return "Decimal64";
-                case Decimal128: return "Decimal128";
-                case Decimal256: return "Decimal256";
-                case AggregateFunctionState: return "AggregateFunctionState";
-            }
-
-            throw Exception("Bad type of Field", ErrorCodes::BAD_TYPE_OF_FIELD);
-        }
     };
 
 
@@ -417,6 +389,8 @@ public:
 
 
     Types::Which getType() const { return which; }
+
+    //static constexpr std::string_view getTypeName() { return Types::toString(which); }
     const char * getTypeName() const { return Types::toString(which); }
 
     bool isNull() const { return which == Types::Null; }
@@ -808,7 +782,8 @@ NearestFieldType<std::decay_t<T>> & Field::get()
     constexpr Field::Types::Which target = TypeToEnum<StoredType>::value;
     if (target != which
            && (!isInt64OrUInt64FieldType(target) || !isInt64OrUInt64FieldType(which)))
-        throw Exception(ErrorCodes::LOGICAL_ERROR, "Invalid Field get from type {} to type {}", Types::toString(which), Types::toString(target));
+        throw Exception(ErrorCodes::LOGICAL_ERROR, 
+            "Invalid Field get from type {} to type {}", which, target);
 #endif
 
     StoredType * MAY_ALIAS ptr = reinterpret_cast<StoredType *>(&storage);
@@ -821,8 +796,11 @@ template <typename T>
 auto & Field::safeGet()
 {
     const Types::Which requested = TypeToEnum<NearestFieldType<std::decay_t<T>>>::value;
+
     if (which != requested)
-        throw Exception("Bad get: has " + std::string(getTypeName()) + ", requested " + std::string(Types::toString(requested)), ErrorCodes::BAD_GET);
+        throw Exception(ErrorCodes::BAD_GET, 
+            "Bad get: has {}, requested {}", getTypeName(), requested);
+
     return get<T>();
 }
 

src/DataTypes/DataTypeInterval.h

@@ -27,7 +27,7 @@ public:
 
     DataTypeInterval(IntervalKind kind_) : kind(kind_) {}
 
-    std::string doGetName() const override { return std::string("Interval") + kind.toString(); }
+    std::string doGetName() const override { return fmt::format("Interval{}", kind.toString()); }
     const char * getFamilyName() const override { return "Interval"; }
     TypeIndex getTypeId() const override { return TypeIndex::Interval; }
 

src/DataTypes/registerDataTypeDateTime.cpp

@@ -26,10 +26,8 @@ String getExceptionMessage(
     const String & message, size_t argument_index, const char * argument_name,
     const std::string & context_data_type_name, Field::Types::Which field_type)
 {
-    return std::string("Parameter #") + std::to_string(argument_index) + " '"
-           + argument_name + "' for " + context_data_type_name
-           + message
-           + ", expected: " + Field::Types::toString(field_type) + " literal.";
+    return fmt::format("Parameter #{} '{}' for {}{}, expected {} literal",
+        argument_index, argument_name, context_data_type_name, message, field_type);
 }
 
 template <typename T, ArgumentKind Kind>

src/Disks/IVolume.cpp

@@ -15,22 +15,6 @@ namespace ErrorCodes
     extern const int UNKNOWN_VOLUME_TYPE;
 }
 
-String volumeTypeToString(VolumeType type)
-{
-    switch (type)
-    {
-        case VolumeType::JBOD:
-            return "JBOD";
-        case VolumeType::RAID1:
-            return "RAID1";
-        case VolumeType::SINGLE_DISK:
-            return "SINGLE_DISK";
-        case VolumeType::UNKNOWN:
-            return "UNKNOWN";
-    }
-    throw Exception("Unknown volume type, please add it to DB::volumeTypeToString", ErrorCodes::UNKNOWN_VOLUME_TYPE);
-}
-
 IVolume::IVolume(
     String name_,
     const Poco::Util::AbstractConfiguration & config,

src/Disks/IVolume.h

@@ -16,8 +16,6 @@ enum class VolumeType
     UNKNOWN
 };
 
-String volumeTypeToString(VolumeType t);
-
 class IVolume;
 using VolumePtr = std::shared_ptr<IVolume>;
 using Volumes = std::vector<VolumePtr>;

src/Functions/FunctionBinaryArithmetic.h

@@ -632,7 +632,9 @@ class FunctionBinaryArithmetic : public IFunction
         std::string function_name;
         if (interval_data_type)
         {
-            function_name = String(is_plus ? "add" : "subtract") + interval_data_type->getKind().toString() + 's';
+            function_name = fmt::format("{}{}s",
+                is_plus ? "add" : "subtract",
+                interval_data_type->getKind().toString());
         }
         else
         {

src/Functions/toStartOfInterval.cpp

@@ -261,10 +261,10 @@ public:
                         + ". This argument is optional and must be a constant string with timezone name",
                     ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
             if (first_argument_is_date && result_type_is_date)
-                throw Exception(
-                    "The timezone argument of function " + getName() + " with interval type " + interval_type->getKind().toString()
-                        + " is allowed only when the 1st argument has the type DateTime",
-                    ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
+                throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT,
+                    "The timezone argument of function {} with interval type {} is allowed only when the 1st argument "
+                    "has the type DateTime",
+                        getName(), interval_type->getKind().toString());
         };
 
         if (arguments.size() == 2)

src/IO/Operators.h

@@ -6,6 +6,9 @@
 #include <IO/WriteHelpers.h>
 
 #include <functional>
+#include <type_traits>
+
+#include <common/EnumReflection.h>
 
 
 namespace DB
@@ -41,16 +44,47 @@ struct QuoteManipReadBuffer          : std::reference_wrapper<ReadBuffer> { usin
 struct DoubleQuoteManipReadBuffer    : std::reference_wrapper<ReadBuffer> { using std::reference_wrapper<ReadBuffer>::reference_wrapper; };
 struct BinaryManipReadBuffer         : std::reference_wrapper<ReadBuffer> { using std::reference_wrapper<ReadBuffer>::reference_wrapper; };
 
+inline WriteBuffer & operator<<(WriteBuffer & buf, const auto & x)
+{
+    writeText(x, buf);
+    return buf;
+}
 
-template <typename T>     WriteBuffer & operator<< (WriteBuffer & buf, const T & x)        { writeText(x, buf);     return buf; }
-/// If you do not use the manipulators, the string is displayed without an escape, as is.
-template <> inline        WriteBuffer & operator<< (WriteBuffer & buf, const String & x)   { writeString(x, buf);   return buf; }
-template <> inline        WriteBuffer & operator<< (WriteBuffer & buf, const std::string_view & x)   { writeString(StringRef(x), buf);   return buf; }
-template <> inline WriteBuffer & operator<< (WriteBuffer & buf, const StringRef & x) { writeString(x, buf); return buf; }
-template <> inline        WriteBuffer & operator<< (WriteBuffer & buf, const char & x)     { writeChar(x, buf);     return buf; }
-template <> inline        WriteBuffer & operator<< (WriteBuffer & buf, const pcg32_fast & x) { PcgSerializer::serializePcg32(x, buf); return buf; }
+inline WriteBuffer & operator<<(WriteBuffer & buf, auto x) requires(std::is_enum_v<decltype(x)>)
+{
+    writeString(magic_enum::enum_name(x), buf);   
+    return buf; 
+}
 
-inline WriteBuffer & operator<< (WriteBuffer & buf, const char * x)     { writeCString(x, buf); return buf; }
+inline WriteBuffer & operator<<(WriteBuffer & buf, std::string_view x)
+{
+    writeString(x, buf);
+    return buf;
+}
+
+inline WriteBuffer & operator<<(WriteBuffer & buf, StringRef x)
+{
+    writeString(x, buf); 
+    return buf;
+}
+
+inline WriteBuffer & operator<<(WriteBuffer & buf, char x)     
+{ 
+    writeChar(x, buf);
+    return buf; 
+}
+
+inline WriteBuffer & operator<<(WriteBuffer & buf, const char * x)
+{
+    writeCString(x, buf); 
+    return buf; 
+}
+
+WriteBuffer & operator<<(WriteBuffer & buf, const pcg32_fast & x)
+{ 
+    PcgSerializer::serializePcg32(x, buf);
+    return buf;
+}
 
 inline EscapeManipWriteBuffer      operator<< (WriteBuffer & buf, EscapeManip)      { return buf; }
 inline QuoteManipWriteBuffer       operator<< (WriteBuffer & buf, QuoteManip)       { return buf; }

src/IO/WriteHelpers.h

@@ -42,7 +42,6 @@
 
 #include <Formats/FormatSettings.h>
 
-
 namespace DB
 {
 
@@ -177,17 +176,20 @@ inline void writeFloatText(T x, WriteBuffer & buf)
     buf.write(buffer, result);
 }
 
-
 inline void writeString(const char * data, size_t size, WriteBuffer & buf)
 {
     buf.write(data, size);
 }
 
-inline void writeString(const StringRef & ref, WriteBuffer & buf)
+inline void writeString(StringRef ref, WriteBuffer & buf)
 {
     writeString(ref.data, ref.size, buf);
 }
 
+inline void writeString(std::string_view ref, WriteBuffer & buf)
+{
+    writeString(ref.data(), ref.size(), buf);
+}
 
 /** Writes a C-string without creating a temporary object. If the string is a literal, then `strlen` is executed at the compilation stage.
   * Use when the string is a literal.

src/Interpreters/ActionsDAG.cpp

@@ -30,34 +30,15 @@ namespace ErrorCodes
     extern const int BAD_ARGUMENTS;
 }
 
-const char * ActionsDAG::typeToString(ActionsDAG::ActionType type)
-{
-    switch (type)
-    {
-        case ActionType::INPUT:
-            return "Input";
-        case ActionType::COLUMN:
-            return "Column";
-        case ActionType::ALIAS:
-            return "Alias";
-        case ActionType::ARRAY_JOIN:
-            return "ArrayJoin";
-        case ActionType::FUNCTION:
-            return "Function";
-    }
-
-    __builtin_unreachable();
-}
-
 void ActionsDAG::Node::toTree(JSONBuilder::JSONMap & map) const
 {
-    map.add("Node Type", ActionsDAG::typeToString(type));
+    map.add("Node Type", magic_enum::enum_name(type));
 
     if (result_type)
         map.add("Result Type", result_type->getName());
 
     if (!result_name.empty())
-        map.add("Result Type", ActionsDAG::typeToString(type));
+        map.add("Result Type", magic_enum::enum_name(type));
 
     if (column)
         map.add("Column", column->getName());

src/Interpreters/ActionsDAG.h

@@ -61,8 +61,6 @@ public:
         FUNCTION,
     };
 
-    static const char * typeToString(ActionType type);
-
     struct Node;
     using NodeRawPtrs = std::vector<Node *>;
     using NodeRawConstPtrs = std::vector<const Node *>;

src/Interpreters/ExpressionAnalyzer.cpp

@@ -624,7 +624,7 @@ void makeWindowDescriptionFromAST(const Context & context,
     {
         throw Exception(ErrorCodes::NOT_IMPLEMENTED,
             "Window frame '{}' is not implemented (while processing '{}')",
-            WindowFrame::toString(definition.frame_type),
+            definition.frame_type,
             ast->formatForErrorMessage());
     }
 

src/Interpreters/InterpreterSystemQuery.cpp

@@ -426,7 +426,7 @@ BlockIO InterpreterSystemQuery::execute()
         }
         case Type::STOP_LISTEN_QUERIES:
         case Type::START_LISTEN_QUERIES:
-            throw Exception(String(ASTSystemQuery::typeToString(query.type)) + " is not supported yet", ErrorCodes::NOT_IMPLEMENTED);
+            throw Exception(ErrorCodes::NOT_IMPLEMENTED, "{} is not supported yet", query.type);
         default:
             throw Exception("Unknown type of SYSTEM query", ErrorCodes::BAD_ARGUMENTS);
     }

src/Interpreters/WindowDescription.cpp

@@ -51,7 +51,7 @@ std::string WindowFrame::toString() const
 
 void WindowFrame::toString(WriteBuffer & buf) const
 {
-    buf << toString(type) << " BETWEEN ";
+    buf << type << " BETWEEN ";
     if (begin_type == BoundaryType::Current)
     {
         buf << "CURRENT ROW";
@@ -101,9 +101,9 @@ void WindowFrame::checkValid() const
         {
             throw Exception(ErrorCodes::BAD_ARGUMENTS,
                 "Frame start offset for '{}' frame must be a nonnegative 32-bit integer, '{}' of type '{}' given",
-                toString(type),
+                type,
                 applyVisitor(FieldVisitorToString(), begin_offset),
-                Field::Types::toString(begin_offset.getType()));
+                begin_offset.getType());
         }
 
         if (end_type == BoundaryType::Offset
@@ -114,9 +114,9 @@ void WindowFrame::checkValid() const
         {
             throw Exception(ErrorCodes::BAD_ARGUMENTS,
                 "Frame end offset for '{}' frame must be a nonnegative 32-bit integer, '{}' of type '{}' given",
-                toString(type),
+                type,
                 applyVisitor(FieldVisitorToString(), end_offset),
-                Field::Types::toString(end_offset.getType()));
+                end_offset.getType());
         }
     }
 

src/Interpreters/WindowDescription.h

@@ -73,40 +73,6 @@ struct WindowFrame
             && other.end_preceding == end_preceding
             ;
     }
-
-    static std::string toString(FrameType type)
-    {
-        switch (type)
-        {
-            case FrameType::Rows:
-                return "ROWS";
-            case FrameType::Groups:
-                return "GROUPS";
-            case FrameType::Range:
-                return "RANGE";
-        }
-
-        // Somehow GCC 10 doesn't understand that the above switch is exhaustive.
-        assert(false);
-        return "<unknown frame>";
-    }
-
-    static std::string toString(BoundaryType type)
-    {
-        switch (type)
-        {
-            case BoundaryType::Unbounded:
-                return "UNBOUNDED";
-            case BoundaryType::Offset:
-                return "OFFSET";
-            case BoundaryType::Current:
-                return "CURRENT ROW";
-        }
-
-        // Somehow GCC 10 doesn't understand that the above switch is exhaustive.
-        assert(false);
-        return "<unknown frame boundary>";
-    }
 };
 
 struct WindowDescription

src/Interpreters/convertFieldToType.cpp

@@ -75,8 +75,8 @@ static Field convertNumericType(const Field & from, const IDataType & type)
     if (from.getType() == Field::Types::Int256)
         return convertNumericTypeImpl<Int256, To>(from);
 
-    throw Exception("Type mismatch in IN or VALUES section. Expected: " + type.getName() + ". Got: "
-        + Field::Types::toString(from.getType()), ErrorCodes::TYPE_MISMATCH);
+    throw Exception(ErrorCodes::TYPE_MISMATCH, "Type mismatch in IN or VALUES section. Expected: {}. Got: {}",
+        type.getName(), from.getType());
 }
 
 
@@ -134,8 +134,8 @@ static Field convertDecimalType(const Field & from, const To & type)
     if (from.getType() == Field::Types::Decimal128)
         return convertDecimalToDecimalType<Decimal128>(from, type);
 
-    throw Exception("Type mismatch in IN or VALUES section. Expected: " + type.getName() + ". Got: "
-        + Field::Types::toString(from.getType()), ErrorCodes::TYPE_MISMATCH);
+    throw Exception(ErrorCodes::TYPE_MISMATCH, "Type mismatch in IN or VALUES section. Expected: {}. Got: {}",
+        type.getName(), from.getType());
 }
 
 
@@ -387,8 +387,8 @@ Field convertFieldToTypeImpl(const Field & src, const IDataType & type, const ID
         return convertFieldToType(parsed, type, from_type_hint);
     }
 
-    throw Exception("Type mismatch in IN or VALUES section. Expected: " + type.getName() + ". Got: "
-        + Field::Types::toString(src.getType()), ErrorCodes::TYPE_MISMATCH);
+    throw Exception(ErrorCodes::TYPE_MISMATCH, "Type mismatch in IN or VALUES section. Expected: {}. Got: {}",
+        type.getName(), src.getType());
 }
 
 }

src/Parsers/ASTSystemQuery.cpp

@@ -13,101 +13,10 @@ namespace ErrorCodes
     extern const int LOGICAL_ERROR;
 }
 
-
-const char * ASTSystemQuery::typeToString(Type type)
-{
-    switch (type)
-    {
-        case Type::SHUTDOWN:
-            return "SHUTDOWN";
-        case Type::KILL:
-            return "KILL";
-        case Type::SUSPEND:
-            return "SUSPEND";
-        case Type::DROP_DNS_CACHE:
-            return "DROP DNS CACHE";
-        case Type::DROP_MARK_CACHE:
-            return "DROP MARK CACHE";
-        case Type::DROP_UNCOMPRESSED_CACHE:
-            return "DROP UNCOMPRESSED CACHE";
-        case Type::DROP_MMAP_CACHE:
-            return "DROP MMAP CACHE";
-#if USE_EMBEDDED_COMPILER
-        case Type::DROP_COMPILED_EXPRESSION_CACHE:
-            return "DROP COMPILED EXPRESSION CACHE";
-#endif
-        case Type::STOP_LISTEN_QUERIES:
-            return "STOP LISTEN QUERIES";
-        case Type::START_LISTEN_QUERIES:
-            return "START LISTEN QUERIES";
-        case Type::RESTART_REPLICAS:
-            return "RESTART REPLICAS";
-        case Type::RESTART_REPLICA:
-            return "RESTART REPLICA";
-        case Type::RESTORE_REPLICA:
-            return "RESTORE REPLICA";
-        case Type::DROP_REPLICA:
-            return "DROP REPLICA";
-        case Type::SYNC_REPLICA:
-            return "SYNC REPLICA";
-        case Type::FLUSH_DISTRIBUTED:
-            return "FLUSH DISTRIBUTED";
-        case Type::RELOAD_DICTIONARY:
-            return "RELOAD DICTIONARY";
-        case Type::RELOAD_DICTIONARIES:
-            return "RELOAD DICTIONARIES";
-        case Type::RELOAD_MODEL:
-            return "RELOAD MODEL";
-        case Type::RELOAD_MODELS:
-            return "RELOAD MODELS";
-        case Type::RELOAD_EMBEDDED_DICTIONARIES:
-            return "RELOAD EMBEDDED DICTIONARIES";
-        case Type::RELOAD_CONFIG:
-            return "RELOAD CONFIG";
-        case Type::RELOAD_SYMBOLS:
-            return "RELOAD SYMBOLS";
-        case Type::STOP_MERGES:
-            return "STOP MERGES";
-        case Type::START_MERGES:
-            return "START MERGES";
-        case Type::STOP_TTL_MERGES:
-            return "STOP TTL MERGES";
-        case Type::START_TTL_MERGES:
-            return "START TTL MERGES";
-        case Type::STOP_MOVES:
-            return "STOP MOVES";
-        case Type::START_MOVES:
-            return "START MOVES";
-        case Type::STOP_FETCHES:
-            return "STOP FETCHES";
-        case Type::START_FETCHES:
-            return "START FETCHES";
-        case Type::STOP_REPLICATED_SENDS:
-            return "STOP REPLICATED SENDS";
-        case Type::START_REPLICATED_SENDS:
-            return "START REPLICATED SENDS";
-        case Type::STOP_REPLICATION_QUEUES:
-            return "STOP REPLICATION QUEUES";
-        case Type::START_REPLICATION_QUEUES:
-            return "START REPLICATION QUEUES";
-        case Type::STOP_DISTRIBUTED_SENDS:
-            return "STOP DISTRIBUTED SENDS";
-        case Type::START_DISTRIBUTED_SENDS:
-            return "START DISTRIBUTED SENDS";
-        case Type::FLUSH_LOGS:
-            return "FLUSH LOGS";
-        case Type::RESTART_DISK:
-            return "RESTART DISK";
-        default:
-            throw Exception("Unknown SYSTEM query command", ErrorCodes::LOGICAL_ERROR);
-    }
-}
-
-
 void ASTSystemQuery::formatImpl(const FormatSettings & settings, FormatState &, FormatStateStacked) const
 {
     settings.ostr << (settings.hilite ? hilite_keyword : "") << "SYSTEM ";
-    settings.ostr << typeToString(type) << (settings.hilite ? hilite_none : "");
+    settings.ostr << type << (settings.hilite ? hilite_none : "");
 
     auto print_database_table = [&]
     {

src/Parsers/ASTSystemQuery.h

@@ -62,8 +62,6 @@ public:
         END
     };
 
-    static const char * typeToString(Type type);
-
     Type type = Type::UNKNOWN;
 
     String target_model;

src/Parsers/ASTWindowDefinition.cpp

@@ -98,7 +98,7 @@ void ASTWindowDefinition::formatImpl(const FormatSettings & settings,
             settings.ostr << " ";
         }
 
-        settings.ostr << WindowFrame::toString(frame_type) << " BETWEEN ";
+        settings.ostr << frame_type << " BETWEEN ";
         if (frame_begin_type == WindowFrame::BoundaryType::Current)
         {
             settings.ostr << "CURRENT ROW";

src/Parsers/CommonParsers.cpp

@@ -14,31 +14,18 @@ namespace ErrorCodes
     extern const int LOGICAL_ERROR;
 }
 
-
-ParserKeyword::ParserKeyword(const char * s_) : s(s_)
-{
-}
-
-
-const char * ParserKeyword::getName() const
-{
-    return s;
-}
-
-
 bool ParserKeyword::parseImpl(Pos & pos, ASTPtr & /*node*/, Expected & expected)
 {
     if (pos->type != TokenType::BareWord)
         return false;
 
-    const char * current_word = s;
+    const char * current_word = s.begin();
+    const char * s_end = s.end();
+    const size_t s_length = s.length();
 
-    size_t s_length = strlen(s);
     if (!s_length)
         throw Exception("Logical error: keyword cannot be empty string", ErrorCodes::LOGICAL_ERROR);
 
-    const char * s_end = s + s_length;
-
     while (true)
     {
         expected.add(pos, current_word);

src/Parsers/CommonParsers.h

@@ -13,13 +13,13 @@ namespace DB
 class ParserKeyword : public IParserBase
 {
 private:
-    const char * s;
+    std::string_view s;
 
 public:
-    ParserKeyword(const char * s_);
+    constexpr ParserKeyword(std::string_view s_): s(s_) {}
 
 protected:
-    const char * getName() const override;
+    const char * getName() const override { return s.data(); }
 
     bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected) override;
 };

src/Parsers/ParserSystemQuery.cpp

@@ -6,6 +6,8 @@
 #include <Parsers/ASTLiteral.h>
 #include <Parsers/parseDatabaseAndTableName.h>
 
+#include <span>
+#include <common/EnumReflection.h>
 
 namespace ErrorCodes
 {
@@ -67,13 +69,14 @@ bool ParserSystemQuery::parseImpl(IParser::Pos & pos, ASTPtr & node, Expected &
     auto res = std::make_shared<ASTSystemQuery>();
 
     bool found = false;
-    for (int i = static_cast<int>(Type::UNKNOWN) + 1; i < static_cast<int>(Type::END); ++i)
+
+    for (const auto & [entry, str] : magic_enum::enum_entries<Type>())
     {
-        Type t = static_cast<Type>(i);
-        if (ParserKeyword{ASTSystemQuery::typeToString(t)}.ignore(pos, expected))
+        if (ParserKeyword(UnderscoreToSpace(str)).ignore(pos, expected))
         {
-            res->type = t;
+            res->type = entry;
             found = true;
+            break;
         }
     }
 

src/Processors/Transforms/WindowTransform.cpp

@@ -617,8 +617,8 @@ void WindowTransform::advanceFrameStart()
                 default:
                     throw Exception(ErrorCodes::NOT_IMPLEMENTED,
                         "Frame start type '{}' for frame '{}' is not implemented",
-                        WindowFrame::toString(window_description.frame.begin_type),
-                        WindowFrame::toString(window_description.frame.type));
+                        window_description.frame.begin_type,
+                        window_description.frame.type);
             }
             break;
     }
@@ -849,7 +849,7 @@ void WindowTransform::advanceFrameEnd()
                 default:
                     throw Exception(ErrorCodes::NOT_IMPLEMENTED,
                         "The frame end type '{}' is not implemented",
-                        WindowFrame::toString(window_description.frame.end_type));
+                        window_description.frame.end_type);
             }
             break;
     }

src/Storages/AlterCommands.cpp

@@ -842,53 +842,6 @@ std::optional<MutationCommand> AlterCommand::tryConvertToMutationCommand(Storage
     return result;
 }
 
-
-String alterTypeToString(const AlterCommand::Type type)
-{
-    switch (type)
-    {
-    case AlterCommand::Type::ADD_COLUMN:
-        return "ADD COLUMN";
-    case AlterCommand::Type::ADD_CONSTRAINT:
-        return "ADD CONSTRAINT";
-    case AlterCommand::Type::ADD_INDEX:
-        return "ADD INDEX";
-    case AlterCommand::Type::ADD_PROJECTION:
-        return "ADD PROJECTION";
-    case AlterCommand::Type::COMMENT_COLUMN:
-        return "COMMENT COLUMN";
-    case AlterCommand::Type::DROP_COLUMN:
-        return "DROP COLUMN";
-    case AlterCommand::Type::DROP_CONSTRAINT:
-        return "DROP CONSTRAINT";
-    case AlterCommand::Type::DROP_INDEX:
-        return "DROP INDEX";
-    case AlterCommand::Type::DROP_PROJECTION:
-        return "DROP PROJECTION";
-    case AlterCommand::Type::MODIFY_COLUMN:
-        return "MODIFY COLUMN";
-    case AlterCommand::Type::MODIFY_ORDER_BY:
-        return "MODIFY ORDER BY";
-    case AlterCommand::Type::MODIFY_SAMPLE_BY:
-        return "MODIFY SAMPLE BY";
-    case AlterCommand::Type::MODIFY_TTL:
-        return "MODIFY TTL";
-    case AlterCommand::Type::MODIFY_SETTING:
-        return "MODIFY SETTING";
-    case AlterCommand::Type::RESET_SETTING:
-        return "RESET SETTING";
-    case AlterCommand::Type::MODIFY_QUERY:
-        return "MODIFY QUERY";
-    case AlterCommand::Type::RENAME_COLUMN:
-        return "RENAME COLUMN";
-    case AlterCommand::Type::REMOVE_TTL:
-        return "REMOVE TTL";
-    default:
-        throw Exception("Uninitialized ALTER command", ErrorCodes::LOGICAL_ERROR);
-    }
-
-}
-
 void AlterCommands::apply(StorageInMemoryMetadata & metadata, ContextPtr context) const
 {
     if (!prepared)

src/Storages/AlterCommands.h

@@ -168,9 +168,6 @@ struct AlterCommand
     std::optional<MutationCommand> tryConvertToMutationCommand(StorageInMemoryMetadata & metadata, ContextPtr context) const;
 };
 
-/// Return string representation of AlterCommand::Type
-String alterTypeToString(const AlterCommand::Type type);
-
 class Context;
 
 /// Vector of AlterCommand with several additional functions

src/Storages/IStorage.cpp

@@ -140,9 +140,8 @@ void IStorage::checkAlterIsPossible(const AlterCommands & commands, ContextPtr /
     for (const auto & command : commands)
     {
         if (!command.isCommentAlter())
-            throw Exception(
-                "Alter of type '" + alterTypeToString(command.type) + "' is not supported by storage " + getName(),
-                ErrorCodes::NOT_IMPLEMENTED);
+            throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Alter of type '{}' is not supported by storage {}",
+                command.type, getName());
     }
 }
 

src/Storages/MergeTree/IMergeTreeDataPart.cpp

@@ -480,39 +480,16 @@ UInt64 IMergeTreeDataPart::getIndexSizeInAllocatedBytes() const
     return res;
 }
 
-String IMergeTreeDataPart::stateToString(IMergeTreeDataPart::State state)
-{
-    switch (state)
-    {
-        case State::Temporary:
-            return "Temporary";
-        case State::PreCommitted:
-            return "PreCommitted";
-        case State::Committed:
-            return "Committed";
-        case State::Outdated:
-            return "Outdated";
-        case State::Deleting:
-            return "Deleting";
-        case State::DeleteOnDestroy:
-            return "DeleteOnDestroy";
-    }
-
-    __builtin_unreachable();
-}
-
-String IMergeTreeDataPart::stateString() const
-{
-    return stateToString(state);
-}
-
 void IMergeTreeDataPart::assertState(const std::initializer_list<IMergeTreeDataPart::State> & affordable_states) const
 {
     if (!checkState(affordable_states))
     {
         String states_str;
         for (auto affordable_state : affordable_states)
-            states_str += stateToString(affordable_state) + " ";
+        {
+            states_str += stateString(affordable_state);
+            states_str += ' ';
+        }
 
         throw Exception("Unexpected state of part " + getNameWithState() + ". Expected: " + states_str, ErrorCodes::NOT_FOUND_EXPECTED_DATA_PART);
     }

src/Storages/MergeTree/IMergeTreeDataPart.h

@@ -16,7 +16,6 @@
 
 #include <shared_mutex>
 
-
 namespace zkutil
 {
     class ZooKeeper;
@@ -221,12 +220,6 @@ public:
         DeleteOnDestroy, /// part was moved to another disk and should be deleted in own destructor
     };
 
-    static constexpr auto all_part_states =
-    {
-        State::Temporary, State::PreCommitted, State::Committed, State::Outdated, State::Deleting,
-        State::DeleteOnDestroy
-    };
-
     using TTLInfo = MergeTreeDataPartTTLInfo;
     using TTLInfos = MergeTreeDataPartTTLInfos;
 
@@ -236,14 +229,10 @@ public:
     void setState(State new_state) const;
     State getState() const;
 
-    /// Returns name of state
-    static String stateToString(State state);
-    String stateString() const;
+    static constexpr std::string_view stateString(State state) { return magic_enum::enum_name(state); }
+    constexpr std::string_view stateString() const { return stateString(state); }
 
-    String getNameWithState() const
-    {
-        return name + " (state " + stateString() + ")";
-    }
+    String getNameWithState() const { return fmt::format("{} (state {})", name, stateString()); }
 
     /// Returns true if state of part is one of affordable_states
     bool checkState(const std::initializer_list<State> & affordable_states) const

src/Storages/MergeTree/MergeTreeDataSelectExecutor.cpp

@@ -163,7 +163,7 @@ QueryPlanPtr MergeTreeDataSelectExecutor::read(
     LOG_DEBUG(
         log,
         "Choose {} projection {}",
-        ProjectionDescription::typeToString(query_info.projection->desc->type),
+        query_info.projection->desc->type,
         query_info.projection->desc->name);
 
     Pipes pipes;

src/Storages/ProjectionsDescription.cpp

@@ -27,20 +27,6 @@ namespace ErrorCodes
     extern const int LOGICAL_ERROR;
 };
 
-const char * ProjectionDescription::typeToString(Type type)
-{
-    switch (type)
-    {
-        case Type::Normal:
-            return "normal";
-        case Type::Aggregate:
-            return "aggregate";
-    }
-
-    __builtin_unreachable();
-}
-
-
 bool ProjectionDescription::isPrimaryKeyColumnPossiblyWrappedInFunctions(const ASTPtr & node) const
 {
     const String column_name = node->getColumnName();

src/Storages/ProjectionsDescription.h

@@ -30,8 +30,6 @@ struct ProjectionDescription
 
     static constexpr const char * MINMAX_COUNT_PROJECTION_NAME = "_minmax_count_projection";
 
-    static const char * typeToString(Type type);
-
     /// Definition AST of projection
     ASTPtr definition_ast;
 

src/Storages/StorageBuffer.cpp

@@ -1021,11 +1021,13 @@ void StorageBuffer::checkAlterIsPossible(const AlterCommands & commands, Context
     auto name_deps = getDependentViewsByColumn(local_context);
     for (const auto & command : commands)
     {
-        if (command.type != AlterCommand::Type::ADD_COLUMN && command.type != AlterCommand::Type::MODIFY_COLUMN
-            && command.type != AlterCommand::Type::DROP_COLUMN && command.type != AlterCommand::Type::COMMENT_COLUMN)
-            throw Exception(
-                "Alter of type '" + alterTypeToString(command.type) + "' is not supported by storage " + getName(),
-                ErrorCodes::NOT_IMPLEMENTED);
+        if (command.type != AlterCommand::Type::ADD_COLUMN
+            && command.type != AlterCommand::Type::MODIFY_COLUMN
+            && command.type != AlterCommand::Type::DROP_COLUMN
+            && command.type != AlterCommand::Type::COMMENT_COLUMN)
+            throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Alter of type '{}' is not supported by storage {}",
+                command.type, getName());
+
         if (command.type == AlterCommand::Type::DROP_COLUMN && !command.clear)
         {
             const auto & deps_mv = name_deps[command.column_name];

src/Storages/StorageDistributed.cpp

@@ -785,8 +785,9 @@ void StorageDistributed::checkAlterIsPossible(const AlterCommands & commands, Co
             && command.type != AlterCommand::Type::COMMENT_COLUMN
             && command.type != AlterCommand::Type::RENAME_COLUMN)
 
-            throw Exception("Alter of type '" + alterTypeToString(command.type) + "' is not supported by storage " + getName(),
-                ErrorCodes::NOT_IMPLEMENTED);
+            throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Alter of type '{}' is not supported by storage {}",
+                command.type, getName());
+
         if (command.type == AlterCommand::DROP_COLUMN && !command.clear)
         {
             const auto & deps_mv = name_deps[command.column_name];

src/Storages/StorageMaterializedView.cpp

@@ -308,9 +308,8 @@ void StorageMaterializedView::checkAlterIsPossible(const AlterCommands & command
         for (const auto & command : commands)
         {
             if (!command.isCommentAlter() && command.type != AlterCommand::MODIFY_QUERY)
-                throw Exception(
-                    "Alter of type '" + alterTypeToString(command.type) + "' is not supported by storage " + getName(),
-                    ErrorCodes::NOT_IMPLEMENTED);
+                throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Alter of type '{}' is not supported by storage {}",
+                    command.type, getName());
         }
     }
     else
@@ -318,9 +317,8 @@ void StorageMaterializedView::checkAlterIsPossible(const AlterCommands & command
         for (const auto & command : commands)
         {
             if (!command.isCommentAlter())
-                throw Exception(
-                    "Alter of type '" + alterTypeToString(command.type) + "' is not supported by storage " + getName(),
-                    ErrorCodes::NOT_IMPLEMENTED);
+                throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Alter of type '{}' is not supported by storage {}",
+                    command.type, getName());
         }
     }
 }

src/Storages/StorageMerge.cpp

@@ -625,11 +625,13 @@ void StorageMerge::checkAlterIsPossible(const AlterCommands & commands, ContextP
     auto name_deps = getDependentViewsByColumn(local_context);
     for (const auto & command : commands)
     {
-        if (command.type != AlterCommand::Type::ADD_COLUMN && command.type != AlterCommand::Type::MODIFY_COLUMN
-            && command.type != AlterCommand::Type::DROP_COLUMN && command.type != AlterCommand::Type::COMMENT_COLUMN)
-            throw Exception(
-                "Alter of type '" + alterTypeToString(command.type) + "' is not supported by storage " + getName(),
-                ErrorCodes::NOT_IMPLEMENTED);
+        if (command.type != AlterCommand::Type::ADD_COLUMN
+            && command.type != AlterCommand::Type::MODIFY_COLUMN
+            && command.type != AlterCommand::Type::DROP_COLUMN
+            && command.type != AlterCommand::Type::COMMENT_COLUMN)
+            throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Alter of type '{}' is not supported by storage {}",
+                command.type, getName());
+
         if (command.type == AlterCommand::Type::DROP_COLUMN && !command.clear)
         {
             const auto & deps_mv = name_deps[command.column_name];

src/Storages/StorageNull.cpp

@@ -41,11 +41,13 @@ void StorageNull::checkAlterIsPossible(const AlterCommands & commands, ContextPt
     auto name_deps = getDependentViewsByColumn(context);
     for (const auto & command : commands)
     {
-        if (command.type != AlterCommand::Type::ADD_COLUMN && command.type != AlterCommand::Type::MODIFY_COLUMN
-            && command.type != AlterCommand::Type::DROP_COLUMN && command.type != AlterCommand::Type::COMMENT_COLUMN)
-            throw Exception(
-                "Alter of type '" + alterTypeToString(command.type) + "' is not supported by storage " + getName(),
-                ErrorCodes::NOT_IMPLEMENTED);
+        if (command.type != AlterCommand::Type::ADD_COLUMN 
+            && command.type != AlterCommand::Type::MODIFY_COLUMN
+            && command.type != AlterCommand::Type::DROP_COLUMN 
+            && command.type != AlterCommand::Type::COMMENT_COLUMN)
+            throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Alter of type '{}' is not supported by storage {}",
+                command.type, getName());
+
         if (command.type == AlterCommand::DROP_COLUMN && !command.clear)
         {
             const auto & deps_mv = name_deps[command.column_name];

src/Storages/StorageReplicatedMergeTree.cpp

@@ -5098,7 +5098,7 @@ void StorageReplicatedMergeTree::restoreMetadataInZooKeeper()
 
     auto metadata_snapshot = getInMemoryMetadataPtr();
 
-    const DataPartsVector all_parts = getDataPartsVector(IMergeTreeDataPart::all_part_states);
+    const DataPartsVector all_parts = getAllDataPartsVector();
     Strings active_parts_names;
 
     /// Why all parts (not only Committed) are moved to detached/:

src/Storages/System/StorageSystemParts.cpp

@@ -265,7 +265,7 @@ void StorageSystemParts::processNextStorage(
         /// _state column should be the latest.
         /// Do not use part->getState*, it can be changed from different thread
         if (has_state_column)
-            columns[res_index++]->insert(IMergeTreeDataPart::stateToString(part_state));
+            columns[res_index++]->insert(IMergeTreeDataPart::stateString(part_state));
     }
 }
 

src/Storages/System/StorageSystemProjectionParts.cpp

@@ -282,7 +282,7 @@ void StorageSystemProjectionParts::processNextStorage(
         /// _state column should be the latest.
         /// Do not use part->getState*, it can be changed from different thread
         if (has_state_column)
-            columns[res_index++]->insert(IMergeTreeDataPart::stateToString(part_state));
+            columns[res_index++]->insert(IMergeTreeDataPart::stateString(part_state));
     }
 }
 

src/Storages/System/StorageSystemStoragePolicies.cpp

@@ -6,6 +6,7 @@
 #include <DataTypes/DataTypeNullable.h>
 #include <Processors/Sources/SourceFromSingleChunk.h>
 #include <Interpreters/Context.h>
+#include <common/EnumReflection.h>
 
 
 namespace DB
@@ -68,7 +69,7 @@ Pipe StorageSystemStoragePolicies::read(
             for (const auto & disk_ptr : volumes[i]->getDisks())
                 disks.push_back(disk_ptr->getName());
             col_disks->insert(disks);
-            col_volume_type->insert(volumeTypeToString(volumes[i]->getType()));
+            col_volume_type->insert(magic_enum::enum_name(volumes[i]->getType()));
             col_max_part_size->insert(volumes[i]->max_data_part_size);
             col_move_factor->insert(policy_ptr->getMoveFactor());
             col_prefer_not_to_merge->insert(volumes[i]->areMergesAvoided() ? 1 : 0);