/*
    * Copyright 2021 TiKV Project Authors.
    *
    * Licensed 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.tikv.common.expression;
  
  import java.io.Serializable;
  import java.util.List;
  import org.tikv.common.types.DataType;
  
  public abstract class Expression implements Serializable {
    protected DataType dataType;
    protected boolean resolved;
  
    public Expression(DataType dataType) {
      this.dataType = dataType;
      this.resolved = true;
    }
  
    public Expression() {
      this.resolved = false;
    }
  
    public abstract List<Expression> getChildren();
  
    public abstract <R, C> R accept(Visitor<R, C> visitor, C context);
  
    public boolean isResolved() {
      return getChildren().stream().allMatch(Expression::isResolved);
    }
  
    public DataType getDataType() {
      return dataType;
    }
  
    public void setDataType(DataType dataType) {
      this.dataType = dataType;
    }
  }