englefly commented on code in PR #11802: URL: https://github.com/apache/doris/pull/11802#discussion_r948887249
########## fe/fe-core/src/main/java/org/apache/doris/nereids/util/TypeCoercionUtils.java: ########## @@ -0,0 +1,292 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you 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. + +package org.apache.doris.nereids.util; + +import org.apache.doris.nereids.annotation.Developing; +import org.apache.doris.nereids.trees.expressions.Cast; +import org.apache.doris.nereids.trees.expressions.Expression; +import org.apache.doris.nereids.types.BigIntType; +import org.apache.doris.nereids.types.BooleanType; +import org.apache.doris.nereids.types.DataType; +import org.apache.doris.nereids.types.DecimalType; +import org.apache.doris.nereids.types.DoubleType; +import org.apache.doris.nereids.types.FloatType; +import org.apache.doris.nereids.types.IntegerType; +import org.apache.doris.nereids.types.LargeIntType; +import org.apache.doris.nereids.types.NullType; +import org.apache.doris.nereids.types.SmallIntType; +import org.apache.doris.nereids.types.StringType; +import org.apache.doris.nereids.types.TinyIntType; +import org.apache.doris.nereids.types.VarcharType; +import org.apache.doris.nereids.types.coercion.AbstractDataType; +import org.apache.doris.nereids.types.coercion.CharacterType; +import org.apache.doris.nereids.types.coercion.FractionalType; +import org.apache.doris.nereids.types.coercion.IntegralType; +import org.apache.doris.nereids.types.coercion.NumericType; +import org.apache.doris.nereids.types.coercion.PrimitiveType; +import org.apache.doris.nereids.types.coercion.TypeCollection; + +import com.google.common.collect.ImmutableList; +import com.google.common.collect.Lists; +import com.google.common.collect.Sets; + +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.function.Supplier; +import java.util.stream.Collectors; +import java.util.stream.Stream; + +/** + * Utils for type coercion. + */ +public class TypeCoercionUtils { + + /** + * numeric type precedence for type promotion. + */ + public static final List<DataType> NUMERIC_PRECEDENCE = ImmutableList.of( + DoubleType.INSTANCE, + LargeIntType.INSTANCE, + FloatType.INSTANCE, + BigIntType.INSTANCE, + IntegerType.INSTANCE, + SmallIntType.INSTANCE, + TinyIntType.INSTANCE + ); + + /** + * Return Optional.empty() if cannot do implicit cast. + * TODO: datetime and date type + */ + @Developing + public static Optional<DataType> implicitCast(DataType input, AbstractDataType expected) { + DataType returnType = null; + if (expected.acceptsType(input)) { + // If the expected type is already a parent of the input type, no need to cast. + return Optional.of(input); + } + if (expected instanceof TypeCollection) { + TypeCollection typeCollection = (TypeCollection) expected; + // use origin datatype first. use implicit cast instead if origin type cannot be accepted. + return Stream.<Supplier<Optional<DataType>>>of( + () -> typeCollection.getTypes().stream() + .filter(e -> e.acceptsType(input)) + .map(e -> input) + .findFirst(), + () -> typeCollection.getTypes().stream() + .map(e -> implicitCast(input, e)) + .filter(Optional::isPresent) + .map(Optional::get) + .findFirst()) + .map(Supplier::get) + .filter(Optional::isPresent) + .map(Optional::get) + .findFirst(); + } + if (input.isNullType()) { + // Cast null type (usually from null literals) into target types + returnType = expected.defaultConcreteType(); + } else if (input.isNumericType() && expected instanceof DecimalType) { + // If input is a numeric type but not decimal, and we expect a decimal type, + // cast the input to decimal. + returnType = DecimalType.forType(input); + } else if (input.isNumericType() && expected instanceof NumericType) { + // For any other numeric types, implicitly cast to each other, e.g. bigint -> int, int -> bigint + returnType = (DataType) expected; + } else if (input.isStringType()) { + if (expected instanceof DecimalType) { + returnType = DecimalType.SYSTEM_DEFAULT; + } else if (expected instanceof NumericType) { + returnType = expected.defaultConcreteType(); + } + } else if (input.isPrimitive() && !input.isStringType() && expected instanceof CharacterType) { + returnType = StringType.INSTANCE; + } + + // could not do implicit cast, just return null. Throw exception in check analysis. + return Optional.ofNullable(returnType); + } + + /** + * return ture if two type could do type coercion. + */ + public static boolean canHandleTypeCoercion(DataType leftType, DataType rightType) { + if (leftType instanceof DecimalType && rightType instanceof NullType) { + return true; + } + if (leftType instanceof NullType && rightType instanceof DecimalType) { + return true; + } + if (!(leftType instanceof DecimalType) && !(rightType instanceof DecimalType) && !leftType.equals(rightType)) { + return true; + } + return false; + } + + + + /** + * find the tightest common type for two type + */ + @Developing + public static Optional<DataType> findTightestCommonType(DataType left, DataType right) { + // TODO: compatible with origin planner and BE + // TODO: when add new type, add it to here + DataType tightestCommonType = null; + if (left.equals(right)) { + tightestCommonType = left; + } else if (left instanceof NullType) { + tightestCommonType = right; + } else if (right instanceof NullType) { + tightestCommonType = left; + } else if (left instanceof IntegralType && right instanceof DecimalType + && ((DecimalType) right).isWiderThan(left)) { Review Comment: do we missed the case: left is integral and right is decimal but (NOT right.isWiderThan(left)) ########## fe/fe-core/src/main/java/org/apache/doris/nereids/rules/expression/rewrite/rules/TypeCoercion.java: ########## @@ -0,0 +1,173 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you 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. + +package org.apache.doris.nereids.rules.expression.rewrite.rules; + +import org.apache.doris.nereids.annotation.Developing; +import org.apache.doris.nereids.rules.expression.rewrite.AbstractExpressionRewriteRule; +import org.apache.doris.nereids.rules.expression.rewrite.ExpressionRewriteContext; +import org.apache.doris.nereids.trees.expressions.BinaryOperator; +import org.apache.doris.nereids.trees.expressions.CaseWhen; +import org.apache.doris.nereids.trees.expressions.Cast; +import org.apache.doris.nereids.trees.expressions.Expression; +import org.apache.doris.nereids.trees.expressions.InPredicate; +import org.apache.doris.nereids.trees.expressions.typecoercion.ImplicitCastInputTypes; +import org.apache.doris.nereids.types.DataType; +import org.apache.doris.nereids.types.coercion.AbstractDataType; +import org.apache.doris.nereids.util.TypeCoercionUtils; + +import com.google.common.collect.Lists; + +import java.util.List; +import java.util.Optional; +import java.util.concurrent.atomic.AtomicInteger; +import java.util.stream.Collectors; + +/** + * a rule to add implicit cast for expressions. + */ +@Developing +public class TypeCoercion extends AbstractExpressionRewriteRule { + + public static final TypeCoercion INSTANCE = new TypeCoercion(); + + @Override + public Expression rewrite(Expression expr, ExpressionRewriteContext ctx) { + if (expr instanceof ImplicitCastInputTypes) { + return visitImplicitCastInputTypes(expr, ctx); + } else { + return super.rewrite(expr, ctx); + } + } + + // TODO: add other expression visitor function to do type coercion if necessary. + + @Override + public Expression visitBinaryOperator(BinaryOperator binaryOperator, ExpressionRewriteContext context) { + Expression left = rewrite(binaryOperator.left(), context); + Expression right = rewrite(binaryOperator.right(), context); + if (!TypeCoercionUtils.canHandleTypeCoercion(left.getDataType(), right.getDataType())) { + return binaryOperator.withChildren(left, right); + } + return TypeCoercionUtils.findTightestCommonType(left.getDataType(), right.getDataType()) + .map(commonType -> { + if (binaryOperator.inputType().acceptsType(commonType) && ( + !left.getDataType().equals(commonType) || !right.getDataType().equals(commonType))) { + Expression newLeft = left; + Expression newRight = right; + if (!left.getDataType().equals(commonType)) { + newLeft = new Cast(left, commonType); Review Comment: from efficiency perspective, here we will traverse the left child top-down again. Shall we combine this traverse with the traverse in line 61? ########## fe/fe-core/src/main/java/org/apache/doris/nereids/util/TypeCoercionUtils.java: ########## @@ -0,0 +1,292 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you 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. + +package org.apache.doris.nereids.util; + +import org.apache.doris.nereids.annotation.Developing; +import org.apache.doris.nereids.trees.expressions.Cast; +import org.apache.doris.nereids.trees.expressions.Expression; +import org.apache.doris.nereids.types.BigIntType; +import org.apache.doris.nereids.types.BooleanType; +import org.apache.doris.nereids.types.DataType; +import org.apache.doris.nereids.types.DecimalType; +import org.apache.doris.nereids.types.DoubleType; +import org.apache.doris.nereids.types.FloatType; +import org.apache.doris.nereids.types.IntegerType; +import org.apache.doris.nereids.types.LargeIntType; +import org.apache.doris.nereids.types.NullType; +import org.apache.doris.nereids.types.SmallIntType; +import org.apache.doris.nereids.types.StringType; +import org.apache.doris.nereids.types.TinyIntType; +import org.apache.doris.nereids.types.VarcharType; +import org.apache.doris.nereids.types.coercion.AbstractDataType; +import org.apache.doris.nereids.types.coercion.CharacterType; +import org.apache.doris.nereids.types.coercion.FractionalType; +import org.apache.doris.nereids.types.coercion.IntegralType; +import org.apache.doris.nereids.types.coercion.NumericType; +import org.apache.doris.nereids.types.coercion.PrimitiveType; +import org.apache.doris.nereids.types.coercion.TypeCollection; + +import com.google.common.collect.ImmutableList; +import com.google.common.collect.Lists; +import com.google.common.collect.Sets; + +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.function.Supplier; +import java.util.stream.Collectors; +import java.util.stream.Stream; + +/** + * Utils for type coercion. + */ +public class TypeCoercionUtils { + + /** + * numeric type precedence for type promotion. + */ + public static final List<DataType> NUMERIC_PRECEDENCE = ImmutableList.of( + DoubleType.INSTANCE, + LargeIntType.INSTANCE, + FloatType.INSTANCE, + BigIntType.INSTANCE, + IntegerType.INSTANCE, + SmallIntType.INSTANCE, + TinyIntType.INSTANCE + ); + + /** + * Return Optional.empty() if cannot do implicit cast. + * TODO: datetime and date type + */ + @Developing + public static Optional<DataType> implicitCast(DataType input, AbstractDataType expected) { + DataType returnType = null; + if (expected.acceptsType(input)) { + // If the expected type is already a parent of the input type, no need to cast. + return Optional.of(input); + } + if (expected instanceof TypeCollection) { + TypeCollection typeCollection = (TypeCollection) expected; + // use origin datatype first. use implicit cast instead if origin type cannot be accepted. + return Stream.<Supplier<Optional<DataType>>>of( + () -> typeCollection.getTypes().stream() + .filter(e -> e.acceptsType(input)) + .map(e -> input) + .findFirst(), + () -> typeCollection.getTypes().stream() + .map(e -> implicitCast(input, e)) + .filter(Optional::isPresent) + .map(Optional::get) + .findFirst()) + .map(Supplier::get) + .filter(Optional::isPresent) + .map(Optional::get) + .findFirst(); + } + if (input.isNullType()) { + // Cast null type (usually from null literals) into target types + returnType = expected.defaultConcreteType(); + } else if (input.isNumericType() && expected instanceof DecimalType) { + // If input is a numeric type but not decimal, and we expect a decimal type, + // cast the input to decimal. + returnType = DecimalType.forType(input); + } else if (input.isNumericType() && expected instanceof NumericType) { + // For any other numeric types, implicitly cast to each other, e.g. bigint -> int, int -> bigint + returnType = (DataType) expected; + } else if (input.isStringType()) { + if (expected instanceof DecimalType) { + returnType = DecimalType.SYSTEM_DEFAULT; + } else if (expected instanceof NumericType) { + returnType = expected.defaultConcreteType(); + } + } else if (input.isPrimitive() && !input.isStringType() && expected instanceof CharacterType) { + returnType = StringType.INSTANCE; + } + + // could not do implicit cast, just return null. Throw exception in check analysis. + return Optional.ofNullable(returnType); + } + + /** + * return ture if two type could do type coercion. + */ + public static boolean canHandleTypeCoercion(DataType leftType, DataType rightType) { + if (leftType instanceof DecimalType && rightType instanceof NullType) { + return true; + } + if (leftType instanceof NullType && rightType instanceof DecimalType) { + return true; + } + if (!(leftType instanceof DecimalType) && !(rightType instanceof DecimalType) && !leftType.equals(rightType)) { + return true; + } + return false; + } + + + + /** + * find the tightest common type for two type + */ + @Developing + public static Optional<DataType> findTightestCommonType(DataType left, DataType right) { + // TODO: compatible with origin planner and BE + // TODO: when add new type, add it to here + DataType tightestCommonType = null; + if (left.equals(right)) { + tightestCommonType = left; + } else if (left instanceof NullType) { + tightestCommonType = right; Review Comment: when left and right are both nullable, why we choose right? -- This is an automated message from the Apache Git Service. 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