discard_output Specification(4.0)

Sometimes it is necessary to describe parts of the external format as an in_map, despite the lack of interest in processing the decoded data. That is, when there are more complex types of filler data and this information is to be discarded.

in_map FillerInMap: external(FillerRecord),
internal(EmptyInternal), discard_output {
    automatic;
};

in_map DataInMap: external(DataRecord),
target_internal(DataTarget) {
    automatic;
};

decoder TotalDecoder: in_map(FillerInMap), in_map(DataInMap);

This example will produce DataTarget UDRs and discard any filler (assuming that the referred formats have been properly defined).