pub fn infer_type(value: &ParseValue) -> Option<FieldType>Expand description
Infer a field type from a value, as getType does.
None means “no type”, not “unknown”. A literal null yields undefined upstream, and
the write path skips the field rather than creating it, which is why writing null to a new
field never adds a column. Returning Option here keeps that distinction at the type level
instead of leaving it to a caller to remember.
A tagged value with its required member missing also yields None: upstream’s switch breaks
out of the case and falls through to returning undefined, so {"__type":"Pointer"} with no
className is not a Pointer and not an error at this stage.