Hello,
The spec has the following language about union type ids: """ Types buffer: A buffer of 8-bit signed integers. Each type in the union has a corresponding type id whose values are found in this buffer. A union with more than 127 possible types can be modeled as a union of unions. """ https://arrow.apache.org/docs/format/Columnar.html#union-layout However, in several places the C++ code assumes type ids are unsigned. Java doesn't seem to implement type ids (and there is no integration task for union types). In the flatbuffers description, the type ids array is modeled as an array of signed 32-bit integers. Moreover, according to the language above, type ids should be restricted to the [0, 127] interval? Which one should it be? Regards Antoine.
