Hello Zach, > Why can't this be something other than a runtime exception?
Your point is well taken. I have made this change https://issues.apache.org/bugzilla/show_bug.cgi?id=46580 The new exception (NotImplementedException) is public so you can check for it specifically, but it is still unchecked thereby not forcing clients of the evaluator API to handle it. An example of what the stack trace might look like now: Exception in thread "main" org.apache.poi.ss.formula.eval.NotImplementedException: Error evaluating cell Sheet1!A1 at org.apache.poi.ss.formula.WorkbookEvaluator.addExceptionInfo(WorkbookEvaluator.java:254) at org.apache.poi.ss.formula.WorkbookEvaluator.evaluateAny(WorkbookEvaluator.java:225) at org.apache.poi.ss.formula.WorkbookEvaluator.evaluate(WorkbookEvaluator.java:180) at org.apache.poi.hssf.usermodel.HSSFFormulaEvaluator.evaluateFormulaCellValue(HSSFFormulaEvaluator.java:297) at org.apache.poi.hssf.usermodel.HSSFFormulaEvaluator.evaluateInCell(HSSFFormulaEvaluator.java:217) at example.poi.TestNotImpl.main(TestPOIPrevVer.java:30) Caused by: org.apache.poi.ss.formula.eval.NotImplementedException: org.apache.poi.hssf.record.formula.functions.Datedif at org.apache.poi.hssf.record.formula.functions.NotImplementedFunction.evaluate(NotImplementedFunction.java:42) at org.apache.poi.hssf.record.formula.eval.FuncVarEval.evaluate(FuncVarEval.java:41) at org.apache.poi.ss.formula.WorkbookEvaluator.invokeOperation(WorkbookEvaluator.java:394) at org.apache.poi.ss.formula.WorkbookEvaluator.evaluateFormula(WorkbookEvaluator.java:329) at org.apache.poi.ss.formula.WorkbookEvaluator.evaluateAny(WorkbookEvaluator.java:216) ... 4 more regards, Josh
