feat: Add toPrestoTypeSql() for Presto SQL type formatting (#16876)

velox/exec/fuzzer/PrestoQueryRunner.cpp

@@ -40,6 +40,7 @@
 #include "velox/functions/prestosql/types/IPPrefixType.h"
 #include "velox/functions/prestosql/types/JsonType.h"
 #include "velox/functions/prestosql/types/KHyperLogLogType.h"
+#include "velox/functions/prestosql/types/PrestoTypeSql.h"
 #include "velox/functions/prestosql/types/QDigestType.h"
 #include "velox/functions/prestosql/types/SetDigestType.h"
 #include "velox/functions/prestosql/types/SfmSketchType.h"
@@ -396,7 +397,7 @@ std::string PrestoQueryRunner::createTable(
   for (auto i = 0; i < inputType->size(); ++i) {
     appendComma(i, nullValues);
     nullValues << fmt::format(
-        "cast(null as {})", toTypeSql(inputType->childAt(i)));
+        "cast(null as {})", toPrestoTypeSql(inputType->childAt(i)));
   }
 
   execute(fmt::format("DROP TABLE IF EXISTS {}", name));

velox/exec/fuzzer/PrestoSql.cpp

@@ -19,6 +19,7 @@
 #include "velox/exec/fuzzer/PrestoQueryRunner.h"
 #include "velox/exec/fuzzer/ReferenceQueryRunner.h"
 #include "velox/functions/prestosql/types/JsonType.h"
+#include "velox/functions/prestosql/types/PrestoTypeSql.h"
 #include "velox/vector/SimpleVector.h"
 
 namespace facebook::velox::exec::test {
@@ -71,36 +72,6 @@ void appendComma(int32_t i, std::stringstream& sql) {
   }
 }
 
-// Returns the SQL string of the given type.
-std::string toTypeSql(const TypePtr& type) {
-  switch (type->kind()) {
-    case TypeKind::ARRAY:
-      return fmt::format("ARRAY({})", toTypeSql(type->childAt(0)));
-    case TypeKind::MAP:
-      return fmt::format(
-          "MAP({}, {})",
-          toTypeSql(type->childAt(0)),
-          toTypeSql(type->childAt(1)));
-    case TypeKind::ROW: {
-      const auto& rowType = type->asRow();
-      std::stringstream sql;
-      sql << "ROW(";
-      for (auto i = 0; i < type->size(); ++i) {
-        appendComma(i, sql);
-        // TODO Field names may need to be quoted.
-        sql << rowType.nameOf(i) << " " << toTypeSql(type->childAt(i));
-      }
-      sql << ")";
-      return sql.str();
-    }
-    default:
-      if (type->isPrimitiveType()) {
-        return type->toString();
-      }
-      VELOX_UNSUPPORTED("Type is not supported: {}", type->toString());
-  }
-}
-
 std::string toLambdaSql(const core::LambdaTypedExprPtr& lambda) {
   std::stringstream sql;
   const auto& signature = lambda->signature();
@@ -346,7 +317,7 @@ std::string toCastSql(const core::CastTypedExpr& cast) {
     sql << "cast(";
   }
   toCallInputsSql(cast.inputs(), sql);
-  sql << " as " << toTypeSql(cast.type());
+  sql << " as " << facebook::velox::toPrestoTypeSql(cast.type());
   sql << ")";
   return sql.str();
 }
@@ -355,7 +326,9 @@ std::string toConcatSql(const core::ConcatTypedExpr& concat) {
   std::stringstream input;
   toCallInputsSql(concat.inputs(), input);
   return fmt::format(
-      "cast(row({}) as {})", input.str(), toTypeSql(concat.type()));
+      "cast(row({}) as {})",
+      input.str(),
+      facebook::velox::toPrestoTypeSql(concat.type()));
 }
 
 template <typename T>
@@ -381,7 +354,7 @@ std::string getConstantValue(const core::ConstantTypedExpr& expr) {
 
 std::string toConstantSql(const core::ConstantTypedExpr& constant) {
   const auto& type = constant.type();
-  const auto typeSql = toTypeSql(type);
+  const auto typeSql = facebook::velox::toPrestoTypeSql(type);
 
   std::stringstream sql;
   if (constant.isNull()) {

velox/exec/fuzzer/PrestoSql.h

@@ -23,9 +23,6 @@ namespace facebook::velox::exec::test {
 /// than 0.
 void appendComma(int32_t i, std::stringstream& sql);
 
-/// Return the SQL string of type.
-std::string toTypeSql(const TypePtr& type);
-
 /// Converts input expressions into SQL string and appends to a given
 /// stringstream.
 void toCallInputsSql(

velox/exec/fuzzer/tests/PrestoSqlTest.cpp

@@ -18,51 +18,10 @@
 
 #include "velox/common/base/tests/GTestUtils.h"
 #include "velox/exec/fuzzer/PrestoSql.h"
-#include "velox/functions/prestosql/types/JsonType.h"
-#include "velox/functions/prestosql/types/KHyperLogLogType.h"
-#include "velox/functions/prestosql/types/QDigestType.h"
-#include "velox/functions/prestosql/types/SetDigestType.h"
-#include "velox/functions/prestosql/types/TDigestType.h"
-#include "velox/functions/prestosql/types/TimestampWithTimeZoneType.h"
 
 namespace facebook::velox::exec::test {
 namespace {
 
-TEST(PrestoSqlTest, toTypeSql) {
-  EXPECT_EQ(toTypeSql(BOOLEAN()), "BOOLEAN");
-  EXPECT_EQ(toTypeSql(TINYINT()), "TINYINT");
-  EXPECT_EQ(toTypeSql(SMALLINT()), "SMALLINT");
-  EXPECT_EQ(toTypeSql(INTEGER()), "INTEGER");
-  EXPECT_EQ(toTypeSql(BIGINT()), "BIGINT");
-  EXPECT_EQ(toTypeSql(REAL()), "REAL");
-  EXPECT_EQ(toTypeSql(DOUBLE()), "DOUBLE");
-  EXPECT_EQ(toTypeSql(VARCHAR()), "VARCHAR");
-  EXPECT_EQ(toTypeSql(VARBINARY()), "VARBINARY");
-  EXPECT_EQ(toTypeSql(TDIGEST(DOUBLE())), "TDIGEST(DOUBLE)");
-  EXPECT_EQ(toTypeSql(TIMESTAMP()), "TIMESTAMP");
-  EXPECT_EQ(toTypeSql(QDIGEST(DOUBLE())), "QDIGEST(DOUBLE)");
-  EXPECT_EQ(toTypeSql(QDIGEST(BIGINT())), "QDIGEST(BIGINT)");
-  EXPECT_EQ(toTypeSql(QDIGEST(REAL())), "QDIGEST(REAL)");
-  EXPECT_EQ(toTypeSql(SETDIGEST()), "SETDIGEST");
-  EXPECT_EQ(toTypeSql(KHYPERLOGLOG()), "KHYPERLOGLOG");
-  EXPECT_EQ(toTypeSql(DATE()), "DATE");
-  EXPECT_EQ(toTypeSql(TIMESTAMP_WITH_TIME_ZONE()), "TIMESTAMP WITH TIME ZONE");
-  EXPECT_EQ(toTypeSql(ARRAY(BOOLEAN())), "ARRAY(BOOLEAN)");
-  EXPECT_EQ(toTypeSql(MAP(BOOLEAN(), INTEGER())), "MAP(BOOLEAN, INTEGER)");
-  EXPECT_EQ(
-      toTypeSql(ROW({{"a", BOOLEAN()}, {"b", INTEGER()}})),
-      "ROW(a BOOLEAN, b INTEGER)");
-  EXPECT_EQ(
-      toTypeSql(
-          ROW({{"a_", BOOLEAN()}, {"b$", INTEGER()}, {"c d", INTEGER()}})),
-      "ROW(a_ BOOLEAN, b$ INTEGER, c d INTEGER)");
-  EXPECT_EQ(toTypeSql(JSON()), "JSON");
-  EXPECT_EQ(toTypeSql(UNKNOWN()), "UNKNOWN");
-  VELOX_ASSERT_THROW(
-      toTypeSql(FUNCTION({INTEGER()}, INTEGER())),
-      "Type is not supported: FUNCTION");
-}
-
 void toUnaryOperator(
     const std::string& operatorName,
     const std::string& expectedSql) {

velox/functions/prestosql/types/CMakeLists.txt

@@ -13,10 +13,12 @@
 # limitations under the License.
 
 add_subdirectory(parser)
+
 velox_add_library(
   velox_presto_types
   BigintEnumRegistration.cpp
   BigintEnumType.cpp
+  PrestoTypeSql.cpp
   BingTileRegistration.cpp
   BingTileType.cpp
   EnumTypeBase.cpp

velox/functions/prestosql/types/PrestoTypeSql.cpp

@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "velox/functions/prestosql/types/PrestoTypeSql.h"
+
+#include <fmt/format.h>
+#include <velox/common/base/Exceptions.h>
+#include <iomanip>
+#include <sstream>
+
+namespace facebook::velox {
+
+namespace {
+bool isPlainArray(const Type& type) {
+  return type.isArray() && typeid(type) == typeid(ArrayType);
+}
+
+bool isPlainMap(const Type& type) {
+  return type.isMap() && typeid(type) == typeid(MapType);
+}
+
+bool isPlainRow(const Type& type) {
+  return type.isRow() && typeid(type) == typeid(RowType);
+}
+
+// Returns true if a ROW field name needs quoting in Presto SQL.
+// Field names that are not simple identifiers (letters, digits, underscores
+// starting with a letter or underscore) must be quoted.
+bool needsQuoting(const std::string& name) {
+  if (name.empty()) {
+    return false;
+  }
+  if (name[0] != '_' && !std::isalpha(name[0])) {
+    return true;
+  }
+  for (auto c : name) {
+    if (c != '_' && !std::isalnum(c)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+} // namespace
+
+std::string toPrestoTypeSql(const TypePtr& type) {
+  if (isPlainArray(*type)) {
+    return fmt::format("ARRAY({})", toPrestoTypeSql(type->childAt(0)));
+  }
+
+  if (isPlainMap(*type)) {
+    return fmt::format(
+        "MAP({}, {})",
+        toPrestoTypeSql(type->childAt(0)),
+        toPrestoTypeSql(type->childAt(1)));
+  }
+
+  if (isPlainRow(*type)) {
+    const auto& rowType = type->asRow();
+    std::stringstream sql;
+    sql << "ROW(";
+    for (auto i = 0; i < type->size(); ++i) {
+      if (i > 0) {
+        sql << ", ";
+      }
+      const auto& name = rowType.nameOf(i);
+      if (!name.empty()) {
+        if (needsQuoting(name)) {
+          sql << std::quoted(name, '"', '"') << " ";
+        } else {
+          sql << name << " ";
+        }
+      }
+      sql << toPrestoTypeSql(type->childAt(i));
+    }
+    sql << ")";
+    return sql.str();
+  }
+
+  // Primitive types and custom types (e.g. IPPREFIX, BINGTILE).
+  // For parameterized types (e.g. TDIGEST(DOUBLE), DECIMAL(10, 2)),
+  // append parameters.
+  const auto& params = type->parameters();
+  if (params.empty()) {
+    return type->name();
+  }
+
+  std::stringstream sql;
+  sql << type->name() << "(";
+  for (auto i = 0; i < params.size(); ++i) {
+    if (i > 0) {
+      sql << ", ";
+    }
+    switch (params[i].kind) {
+      case TypeParameterKind::kType:
+        sql << toPrestoTypeSql(params[i].type);
+        break;
+      case TypeParameterKind::kLongLiteral:
+        sql << params[i].longLiteral.value();
+        break;
+      default:
+        VELOX_UNSUPPORTED(
+            "Unsupported type parameter kind: {}",
+            TypeParameterKindName::toName(params[i].kind));
+    }
+  }
+  sql << ")";
+  return sql.str();
+}
+
+} // namespace facebook::velox

velox/functions/prestosql/types/PrestoTypeSql.h

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#pragma once
+
+#include "velox/type/Type.h"
+
+namespace facebook::velox {
+
+/// Returns the Presto SQL string representation of the given type.
+std::string toPrestoTypeSql(const TypePtr& type);
+
+} // namespace facebook::velox

velox/functions/prestosql/types/tests/CMakeLists.txt

@@ -27,6 +27,7 @@ add_executable(
   UuidTypeTest.cpp
   IPAddressTypeTest.cpp
   IPPrefixTypeTest.cpp
+  PrestoTypeSqlTest.cpp
 )
 
 if(VELOX_ENABLE_GEO)