Seems like the type combination you're using (int32 -> uint32) and (int32 -> uint64) don't match the following pattern-matching
https://github.com/apache/arrow/blob/master/cpp/src/arrow/compute/kernels/cast.cc#L191-L192 which avoid using "safe" cast and revert to the following cast implementation (with no explicit check): https://github.com/apache/arrow/blob/master/cpp/src/arrow/compute/kernels/cast.cc#L316-L318 My take on this is that downcasting concept should only apply to same sign integers. I'd propose the following refactor: 1. Rename `allow_int_overflow` to `allow_int_truncate`. Since truncation is still applicable even if there's no downcasting. 2. Refactor code such that the pattern matching is done on possible truncation and not downcasting. The fast casting is only applied to same-sign and size(O) >= size(I). The (possible according to allow_int_truncate) slow and bound checking is done when signed-ness is not matching or there's downcasting. Can you open a JIRA ticket? François On Wed, Nov 14, 2018 at 6:10 AM Romain Francois <rom...@purrple.cat> wrote: > I'm implementing Array$cast() in the R package, i.e. > https://issues.apache.org/jira/browse/ARROW-3741?filter=12344983 > > I'm seeing some weird results when casting from int32 to uint32 and uint64 > (I'm expecting errors here as it's supposed to be safe > > https://github.com/apache/arrow/pull/2959#issuecomment-438606974 > > a <- array(-(1:3)) > a$cast(uint16()) > #> Error in Array__cast(self, target_type, options): Invalid: Integer > value out of bounds > a$cast(uint16()) > #> Error in Array__cast(self, target_type, options): Invalid: Integer > value out of bounds > a$cast(uint32()) > #> arrow::Array > #> [ > #> 4294967295, > #> 4294967294, > #> 4294967293 > #> ] > a$cast(uint32())$type() > #> arrow::UInt32 > #> uint32 > > a$cast(uint64()) > #> arrow::Array > #> [ > #> -1, > #> -2, > #> -3 > #> ] > a$cast(uint64())$type() > #> arrow::UInt64 > #> uint64 > > I don't think this is an R issue. > > Can someone using other front ends to the C++ library check if they get > the same problem ? > > > > -- Sent from my jetpack.
