org.apache.flink.table.planner.expressions.InputTypeSpec.scala Maven / Gradle / Ivy
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This module bridges Table/SQL API and runtime. It contains
all resources that are required during pre-flight and runtime
phase. The content of this module is work-in-progress. It will
replace flink-table-planner once it is stable. See FLINK-11439
and FLIP-32 for more details.
/*
* 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.flink.table.planner.expressions
import org.apache.flink.api.common.typeinfo.TypeInformation
import org.apache.flink.table.planner.validate._
import scala.collection.mutable
/**
* Expressions that have strict data type specification on its inputs.
*/
trait InputTypeSpec extends PlannerExpression {
/**
* Input type specification for each child.
*
* For example, [[Power]] expecting both of the children be of double type should use:
* {{{
* def expectedTypes: Seq[TypeInformation[_]] = DOUBLE_TYPE_INFO :: DOUBLE_TYPE_INFO :: Nil
* }}}
*
* Inputs that don't match the expected type will be safely casted to a higher type. Therefore,
* use the decimal type with caution as all numeric types would be casted to a very
* inefficient type.
*/
private[flink] def expectedTypes: Seq[TypeInformation[_]]
override private[flink] def validateInput(): ValidationResult = {
val typeMismatches = mutable.ArrayBuffer.empty[String]
if(expectedTypes.size != children.size){
return ValidationFailure(
s"""|$this fails on input type size checking: expected types size[${expectedTypes.size}].
|Operands types size[${children.size}].
|""".stripMargin)
}
children.zip(expectedTypes).zipWithIndex.foreach { case ((e, tpe), i) =>
if (e.resultType != tpe) {
typeMismatches += s"expecting $tpe on ${i}th input, get ${e.resultType}"
}
}
if (typeMismatches.isEmpty) {
ValidationSuccess
} else {
ValidationFailure(
s"""|$this fails on input type checking: ${typeMismatches.mkString("[", ", ", "]")}.
|Operand should be casted to proper type
|""".stripMargin)
}
}
}