Provide default missingValues?

Overview

For now spec says that only "" (empty string) should be considered as missing value on non string fields. But current implementations already use for this case insensitive null, none, nil, nan, - because of publishers requests. Implement current specification literally could break some datasets.

PS. Also from spec is not clear about case-sensitivity of missingValues.

[roll]

So my opinion is without default values spec seems clearer but it could hit existent systems.

Problem with default could be that it can’t be cancelled it for example publisher wants to use nil as an actual value not a not a value.

[pwalsh]

We won’t merge #337 until we can support all the changes in the core implementations we maintain. So closing this as it is implemented in #337 , as leaving it open creates confusion.