Hey Mike, Wanted to get your opinion on the issue I've been running into with IBM4690-TLOG schemas. I talked with Steve for a while trying to figure out what was going on and we came to the opinion that there is either an issue with the TLOG schemas, or (perhaps more likely) there is an error in the separatorSuppressionPolicy code when dealing with infix separators in Daffodil.
In the TlogAce.xsd file (https://github.com/DFDLSchemas/IBM4690-TLOG/blob/master/ACE/TlogAce.xsd#L155) it seems that the way the schema and data files were written assumed that the IBM4690 packed format could have a valid zero length representation, ie an optional element that doesn't occur would just be an empty string surrounded by separators. While this works just fine for strings or hex binary that have valid zero length representations, for IBM4690 and other packed binary formats the associated separators aren't processed, and in the TlogAce.xsd file, when the element SpecialTime is missing all subsequent parsed data in the sequence become CustomUserField's as that is the only element that matches the separators (I think). So, just wanted to get your opinion on whether or not this is an issue with the current Daffodil separator suppression policy code or if this is a case of an incorrectly formed schema. Steve may jump in to clarify anything I didn't explain correctly, as he is a bit more familiar with the separatorSuppression code in Daffodil. Thanks, Josh
