src/main/java/org/apache/iotdb/tsfile/read/expression/util/ExpressionPrinter.java

/*
 * 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.iotdb.tsfile.read.expression.util;

import org.apache.iotdb.tsfile.read.expression.IBinaryExpression;
import org.apache.iotdb.tsfile.read.expression.IExpression;
import org.apache.iotdb.tsfile.read.expression.IUnaryExpression;

public class ExpressionPrinter {

  private static final int MAX_DEPTH = 100;
  private static final char PREFIX_CHAR = '\t';
  private static final String[] PREFIX = new String[MAX_DEPTH];

  static {
    StringBuilder stringBuilder = new StringBuilder();
    for (int i = 0; i < MAX_DEPTH; i++) {
      PREFIX[i] = stringBuilder.toString();
      stringBuilder.append(PREFIX_CHAR);
    }
  }

  public static void print(IExpression expression) {
    print(expression, 0);
  }

  private static void print(IExpression expression, int level) {
    if (expression instanceof IUnaryExpression) {
      System.out.println(getPrefix(level) + expression);
    } else {
      System.out.println(getPrefix(level) + expression.getType() + ":");
      print(((IBinaryExpression) expression).getLeft(), level + 1);
      print(((IBinaryExpression) expression).getRight(), level + 1);
    }
  }

  private static String getPrefix(int count) {
    if (count < MAX_DEPTH) {
      return PREFIX[count];
    } else {
      return PREFIX[MAX_DEPTH - 1];
    }
  }
}