Can enum/set be optional? about fix-simple-binary-encoding HOT 2 CLOSED

First, let me say that only Euronext can explain the intention of their schema. We can only comment on what the standard allows. Their schema is based on SBE v1.0. I mention this because the v2.x release candidates removed some attributes from <type> elements and eliminated the inheritance model of <field> because it was deemed confusing.

Nevertheless, v1.0 specification states that "presence mismatch" is an error. If the attribute is specified on both a field and the encoding that it references, the values must be identical. In the case that you cite, I don't see an explicit mismatch.

The v1.0 spec does not explicitly say that presence="optional" is forbidden for bitsets, but it does say There is no explicit null value for multi-value choice encoding [bitset] other than to set all bits off when no choices are selected. So if it is marked optional, it is not an explicit violation, but it seems to be a moot point.

from fix-simple-binary-encoding.

Thank you!

from fix-simple-binary-encoding.