content: package com.alibaba.qlexpress4.runtime.instruction;
  
  import com.alibaba.qlexpress4.QLOptions;
  import com.alibaba.qlexpress4.exception.ErrorReporter;
  import com.alibaba.qlexpress4.runtime.Parameters;
  import com.alibaba.qlexpress4.runtime.QContext;
  import com.alibaba.qlexpress4.runtime.QResult;
  import com.alibaba.qlexpress4.runtime.data.DataValue;
  import com.alibaba.qlexpress4.utils.PrintlnUtils;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.function.Consumer;
  
  /**
   * Operation: new a List with top ${initLength} stack element
   * Input: ${initLength}
   * Output: 1
   * <p>
   * Author: DQinYuan
   */
  public class NewListInstruction extends QLInstruction {
      
      private final int initLength;
      
      public NewListInstruction(ErrorReporter errorReporter, int initLength) {
          super(errorReporter);
          this.initLength = initLength;
      }
      
      @Override
      public QResult execute(QContext qContext, QLOptions qlOptions) {
          Parameters initItems = qContext.pop(initLength);
          List<? super Object> l = new ArrayList<>(initLength);
          for (int i = 0; i < initLength; i++) {
              l.add(initItems.getValue(i));
          }
          qContext.push(new DataValue(l));
          return QResult.NEXT_INSTRUCTION;
      }
      
      @Override
      public int stackInput() {
          return initLength;
      }
      
      @Override
      public int stackOutput() {
          return 1;
      }
      
      @Override
      public void println(int index, int depth, Consumer<String> debug) {
          PrintlnUtils.printlnByCurDepth(depth, index + ": NewList " + initLength, debug);
      }
  }
  