measure/src/main/scala/org/apache/griffin/measure/step/builder/dsl/expr/Expr.scala

/*
 * 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.griffin.measure.step.builder.dsl.expr

/**
 * expr parsed by griffin dsl
 */
trait Expr extends TreeNode with ExprTag with Serializable {

  def desc: String

  def coalesceDesc: String

  def extractSelf: Expr = this

  // execution
  def map(func: Expr => Expr): Expr = func(this)

}