content: package com.alibaba.qlexpress4.runtime.instruction;
  
  import com.alibaba.qlexpress4.QLOptions;
  import com.alibaba.qlexpress4.exception.ErrorReporter;
  import com.alibaba.qlexpress4.exception.QLErrorCodes;
  import com.alibaba.qlexpress4.runtime.Parameters;
  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.util.MethodInvokeUtils;
  import com.alibaba.qlexpress4.utils.PrintlnUtils;
  
  import java.lang.reflect.Array;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.function.Consumer;
  
  /**
   * Operation: Invoke specified method of each object in the list
   * Input: ${argNum} + 1
   * Output: 1, a list composed of return values from methods.
   * Author: DQinYuan
   */
  public class SpreadMethodInvokeInstruction extends QLInstruction {
      
      private final String methodName;
      
      private final int argNum;
      
      public SpreadMethodInvokeInstruction(ErrorReporter errorReporter, String methodName, int argNum) {
          super(errorReporter);
          this.methodName = methodName;
          this.argNum = argNum;
      }
      
      @Override
      public QResult execute(QContext qContext, QLOptions qlOptions) {
          Parameters parameters = qContext.pop(this.argNum + 1);
          Object traversable = parameters.get(0).get();
          if (traversable == null) {
              if (qlOptions.isAvoidNullPointer()) {
                  qContext.push(DataValue.NULL_VALUE);
                  return QResult.NEXT_INSTRUCTION;
              }
              throw errorReporter.reportFormat(QLErrorCodes.NONTRAVERSABLE_OBJECT.name(),
                  QLErrorCodes.NONTRAVERSABLE_OBJECT.getErrorMsg(),
                  "null");
          }
          Class<?>[] type = new Class[this.argNum];
          Object[] params = new Object[this.argNum];
          for (int i = 0; i < this.argNum; i++) {
              Value v = parameters.get(i + 1);
              params[i] = v.get();
              type[i] = v.getType();
          }
          
          if (traversable instanceof Iterable) {
              Iterable<?> iterable = (Iterable<?>)traversable;
              List<? super Object> result = new ArrayList<>();
              for (Object item : iterable) {
                  if (item == null) {
                      if (qlOptions.isAvoidNullPointer()) {
                          result.add(null);
                          continue;
                      }
                      throw errorReporter.report(new NullPointerException(),
                          QLErrorCodes.NULL_METHOD_ACCESS.name(),
                          QLErrorCodes.NULL_METHOD_ACCESS.getErrorMsg());
                  }
                  Value invokeRes = MethodInvokeUtils
                      .findMethodAndInvoke(item, methodName, params, type, qContext.getReflectLoader(), errorReporter);
                  result.add(invokeRes.get());
              }
              qContext.push(new DataValue(result));
          }
          else if (traversable.getClass().isArray()) {
              int arrLen = Array.getLength(traversable);
              List<? super Object> result = new ArrayList<>();
              for (int i = 0; i < arrLen; i++) {
                  Object item = Array.get(traversable, i);
                  if (item == null) {
                      if (qlOptions.isAvoidNullPointer()) {
                          result.add(null);
                          continue;
                      }
                      throw errorReporter.report(new NullPointerException(),
                          QLErrorCodes.NULL_METHOD_ACCESS.name(),
                          QLErrorCodes.NULL_METHOD_ACCESS.getErrorMsg());
                  }
                  Value invokeRes = MethodInvokeUtils
                      .findMethodAndInvoke(item, methodName, params, type, qContext.getReflectLoader(), errorReporter);
                  result.add(invokeRes.get());
              }
              qContext.push(new DataValue(result));
          }
          else {
              throw errorReporter.reportFormat(QLErrorCodes.NONTRAVERSABLE_OBJECT.name(),
                  QLErrorCodes.NONTRAVERSABLE_OBJECT.getErrorMsg(),
                  traversable.getClass().getName());
          }
          return QResult.NEXT_INSTRUCTION;
      }
      
      @Override
      public int stackInput() {
          return argNum + 1;
      }
      
      @Override
      public int stackOutput() {
          return 1;
      }
      
      @Override
      public void println(int index, int depth, Consumer<String> debug) {
          PrintlnUtils.printlnByCurDepth(depth, index + ": SpreadMethodInvoke " + methodName, debug);
      }
  }
  