ConstReadonlyBlank: numberReadonlyFalse: numberReadonlyFloat64: numberReadonlyInt32: numberReadonlyKindMask: 255The bits that describe the kinds of value seen.
ReadonlyNotFinite: numberReadonlyNotUniform: numberReadonlyObject: numberReadonlyString: numberReadonlyTrue: number
What a builder learns about a run as it pushes, as a bitmask handed to
createList: one bit per kind of value seen (bits 0-7, aligned withMixedTypedArrayList.Typeso a run with noObjectbit can be encoded without a second look), plus:NotUniform: some value differs from the run's first;NotFinite: a number was NaN or infinite (a storage policy the builder does not judge).An
Objectis anything else: an error, rich data. The builder cannot tell them apart.