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.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.function.Consumer;
  
  /**
   * Operation: new a Map with top ${keys.length} stack element
   * Input: ${keys.length}
   * Output: 1
   * <p>
   * Author: DQinYuan
   */
  public class NewMapInstruction extends QLInstruction {
      
      private final List<String> keys;
      
      public NewMapInstruction(ErrorReporter errorReporter, List<String> keys) {
          super(errorReporter);
          this.keys = keys;
      }
      
      @Override
      public QResult execute(QContext qContext, QLOptions qlOptions) {
          Parameters initItems = qContext.pop(keys.size());
          Map<String, Object> m = new LinkedHashMap<>();
          for (int i = 0; i < keys.size(); i++) {
              m.put(keys.get(i), initItems.get(i).get());
          }
          qContext.push(new DataValue(m));
          return QResult.NEXT_INSTRUCTION;
      }
      
      @Override
      public int stackInput() {
          return keys.size();
      }
      
      @Override
      public int stackOutput() {
          return 1;
      }
      
      @Override
      public void println(int index, int depth, Consumer<String> debug) {
          PrintlnUtils.printlnByCurDepth(depth, index + ": NewMap by keys " + keys, debug);
      }
  }
  