content: package com.alibaba.qlexpress4.runtime.operator.arithmetic;
  
  import com.alibaba.qlexpress4.QLOptions;
  import com.alibaba.qlexpress4.QLPrecedences;
  import com.alibaba.qlexpress4.exception.ErrorReporter;
  import com.alibaba.qlexpress4.runtime.QRuntime;
  import com.alibaba.qlexpress4.runtime.Value;
  import com.alibaba.qlexpress4.runtime.operator.base.BaseBinaryOperator;
  
  /**
   * QLExpress只支持String和Number类型的+
   *
   * @author bingo
   */
  public class PlusOperator extends BaseBinaryOperator {
      private static final PlusOperator INSTANCE = new PlusOperator();
      
      private PlusOperator() {
      }
      
      public static PlusOperator getInstance() {
          return INSTANCE;
      }
      
      @Override
      public Object execute(Value left, Value right, QRuntime qRuntime, QLOptions qlOptions,
          ErrorReporter errorReporter) {
          return plus(left, right, qlOptions, errorReporter);
      }
      
      @Override
      public String getOperator() {
          return "+";
      }
      
      @Override
      public int getPriority() {
          return QLPrecedences.ADD;
      }
  }
  