content: package com.alibaba.qlexpress4.runtime.instruction;
  
  import java.util.function.Consumer;
  
  import com.alibaba.qlexpress4.QLOptions;
  import com.alibaba.qlexpress4.exception.ErrorReporter;
  import com.alibaba.qlexpress4.exception.QLErrorCodes;
  import com.alibaba.qlexpress4.runtime.QContext;
  import com.alibaba.qlexpress4.runtime.QResult;
  import com.alibaba.qlexpress4.runtime.Value;
  import com.alibaba.qlexpress4.runtime.data.DataValue;
  import com.alibaba.qlexpress4.runtime.operator.BinaryOperator;
  import com.alibaba.qlexpress4.runtime.trace.ExpressionTrace;
  import com.alibaba.qlexpress4.runtime.util.ThrowUtils;
  import com.alibaba.qlexpress4.utils.PrintlnUtils;
  
  /**
   * Operation: do middle operator +=,&gt;&gt;,&gt;&gt;&gt;,&lt;&lt;,.
   * Input: 2
   * Output: 1, operator result
   * <p>
   * Author: DQinYuan
   */
  public class OperatorInstruction extends QLInstruction {
      
      private final BinaryOperator operator;
      
      private final Integer traceKey;
      
      public OperatorInstruction(ErrorReporter errorReporter, BinaryOperator operator, Integer traceKey) {
          super(errorReporter);
          this.operator = operator;
          this.traceKey = traceKey;
      }
      
      @Override
      public QResult execute(QContext qContext, QLOptions qlOptions) {
          Value rightValue = qContext.pop();
          Value leftValue = qContext.pop();
          try {
              // trace children
              ExpressionTrace expressionTrace = qContext.getTraces().getExpressionTraceByKey(traceKey);
              if (expressionTrace != null) {
                  expressionTrace.getChildren().get(0).valueEvaluated(leftValue.get());
                  expressionTrace.getChildren().get(1).valueEvaluated(rightValue.get());
              }
              
              Object result = operator.execute(leftValue, rightValue, qContext, qlOptions, errorReporter);
              qContext.push(new DataValue(result));
              
              // trace result
              if (expressionTrace != null) {
                  expressionTrace.valueEvaluated(result);
              }
              
              return QResult.NEXT_INSTRUCTION;
          }
          catch (Throwable t) {
              throw ThrowUtils.wrapThrowable(t,
                  errorReporter,
                  QLErrorCodes.EXECUTE_OPERATOR_EXCEPTION.name(),
                  QLErrorCodes.EXECUTE_OPERATOR_EXCEPTION.getErrorMsg(),
                  String.valueOf(leftValue.get()),
                  operator.getOperator(),
                  String.valueOf(rightValue.get()));
          }
      }
      
      @Override
      public int stackInput() {
          return 2;
      }
      
      @Override
      public int stackOutput() {
          return 1;
      }
      
      @Override
      public void println(int index, int depth, Consumer<String> debug) {
          PrintlnUtils.printlnByCurDepth(depth, index + ": Operator " + operator.getOperator(), debug);
      }
      
      public BinaryOperator getOperator() {
          return operator;
      }
  }
  