| /* |
| 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 |
| |
| import scala.reflect.ClassTag |
| |
| trait TreeNode extends Serializable { |
| |
| var children = Seq[TreeNode]() |
| |
| def addChild(expr: TreeNode) = { children :+= expr } |
| def addChildren(exprs: Seq[TreeNode]) = { children ++= exprs } |
| |
| def preOrderTraverseDepthFirst[T, A <: TreeNode](z: T)(seqOp: (A, T) => T, combOp: (T, T) => T)(implicit tag: ClassTag[A]): T = { |
| |
| val clazz = tag.runtimeClass |
| if(clazz.isAssignableFrom(this.getClass)){ |
| val tv = seqOp(this.asInstanceOf[A], z) |
| children.foldLeft(combOp(z, tv)) { (ov, tn) => |
| combOp(ov, tn.preOrderTraverseDepthFirst(z)(seqOp, combOp)) |
| } |
| } |
| else { |
| z |
| } |
| |
| } |
| def postOrderTraverseDepthFirst[T, A <: TreeNode](z: T)(seqOp: (A, T) => T, combOp: (T, T) => T)(implicit tag: ClassTag[A]): T = { |
| |
| val clazz = tag.runtimeClass |
| if(clazz.isAssignableFrom(this.getClass)){ |
| val cv = children.foldLeft(z) { (ov, tn) => |
| combOp(ov, tn.postOrderTraverseDepthFirst(z)(seqOp, combOp)) |
| } |
| combOp(z, seqOp(this.asInstanceOf[A], cv)) |
| } |
| else{ |
| z |
| } |
| } |
| |
| } |