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.exception.UserDefineException;
  import com.alibaba.qlexpress4.runtime.*;
  import com.alibaba.qlexpress4.runtime.data.DataValue;
  import com.alibaba.qlexpress4.runtime.function.CustomFunction;
  import com.alibaba.qlexpress4.runtime.trace.ExpressionTrace;
  import com.alibaba.qlexpress4.runtime.util.ThrowUtils;
  import com.alibaba.qlexpress4.runtime.util.ValueUtils;
  import com.alibaba.qlexpress4.utils.PrintlnUtils;
  
  import java.util.function.Consumer;
  
  /**
   * Operation: call ql function from function table
   * Input: ${argNum}
   * Output: 1 function result
   * Author: DQinYuan
   */
  public class CallFunctionInstruction extends QLInstruction {
      
      private final String functionName;
      
      private final int argNum;
      
      private final Integer traceKey;
      
      public CallFunctionInstruction(ErrorReporter errorReporter, String functionName, int argNum, Integer traceKey) {
          super(errorReporter);
          this.functionName = functionName;
          this.argNum = argNum;
          this.traceKey = traceKey;
      }
      
      @Override
      public QResult execute(QContext qContext, QLOptions qlOptions) {
          CustomFunction function = qContext.getFunction(functionName);
          if (function == null) {
              callLambda(qContext, qlOptions);
              return QResult.NEXT_INSTRUCTION;
          }
          Parameters parameters = qContext.pop(argNum);
          try {
              Object functionResultObj = function.call(qContext, parameters);
              qContext.push(new DataValue(functionResultObj));
              
              // trace
              ExpressionTrace expressionTrace = qContext.getTraces().getExpressionTraceByKey(traceKey);
              if (expressionTrace != null) {
                  expressionTrace.valueEvaluated(functionResultObj);
              }
              
              return QResult.NEXT_INSTRUCTION;
          }
          catch (UserDefineException e) {
              throw ThrowUtils.reportUserDefinedException(errorReporter, e);
          }
          catch (Throwable t) {
              throw ThrowUtils.wrapThrowable(t,
                  errorReporter,
                  QLErrorCodes.INVOKE_FUNCTION_INNER_ERROR.name(),
                  String.format(QLErrorCodes.INVOKE_FUNCTION_INNER_ERROR.getErrorMsg(), functionName, t.getMessage()));
          }
      }
      
      private void callLambda(QContext qContext, QLOptions qlOptions) {
          Object lambdaSymbol = qContext.getSymbolValue(functionName);
          if (lambdaSymbol == null) {
              if (qlOptions.isAvoidNullPointer()) {
                  qContext.pop(argNum);
                  qContext.push(DataValue.NULL_VALUE);
              }
              else {
                  throw errorReporter.report(new NullPointerException(),
                      QLErrorCodes.FUNCTION_NOT_FOUND.name(),
                      String.format(QLErrorCodes.FUNCTION_NOT_FOUND.getErrorMsg(), functionName));
              }
              return;
          }
          if (!(lambdaSymbol instanceof QLambda)) {
              throw errorReporter.report(QLErrorCodes.FUNCTION_TYPE_MISMATCH.name(),
                  String.format(QLErrorCodes.FUNCTION_TYPE_MISMATCH.getErrorMsg(), functionName));
          }
          Parameters parameters = qContext.pop(argNum);
          Object[] parametersArr = new Object[parameters.size()];
          for (int i = 0; i < parametersArr.length; i++) {
              parametersArr[i] = parameters.get(i).get();
          }
          try {
              Value resultValue = ((QLambda)lambdaSymbol).call(parametersArr).getResult();
              qContext.push(ValueUtils.toImmutable(resultValue));
          }
          catch (UserDefineException e) {
              throw ThrowUtils.reportUserDefinedException(errorReporter, e);
          }
          catch (Throwable t) {
              throw ThrowUtils.wrapThrowable(t,
                  errorReporter,
                  QLErrorCodes.INVOKE_LAMBDA_ERROR.name(),
                  QLErrorCodes.INVOKE_LAMBDA_ERROR.getErrorMsg());
          }
      }
      
      @Override
      public int stackInput() {
          return argNum;
      }
      
      @Override
      public int stackOutput() {
          return 1;
      }
      
      @Override
      public void println(int index, int depth, Consumer<String> debug) {
          PrintlnUtils.printlnByCurDepth(depth, index + ": CallFunction " + functionName + " " + argNum, debug);
      }
  }
  