Dragoș Moldovan-Grünfeld created ARROW-16060:
------------------------------------------------
Summary: [C++] subtract_checked support for timestamp("s") and
date32
Key: ARROW-16060
URL: https://issues.apache.org/jira/browse/ARROW-16060
Project: Apache Arrow
Issue Type: Bug
Components: C++
Reporter: Dragoș Moldovan-Grünfeld
This issue surfaced in R. Subtraction between a timestamp and a date only
errors when the date is date32 and the timestamp is expressed in seconds.
While I understand the {{subtract kernel}} doesn't natively support operations
between the various temporal types and some magic (aka implicit casting) is
taking place (via {{DispatchBest}}), I think this is an unexpected behaviour.
If date32 (expressed in days) cannot be converted into seconds, then I would
expect all combinations of date32 and timestamp units to fail. I hope this
makes sense.
Reprex:
{code:r}
a <- Array$create(as.Date("2022-03-25"))
b <- Array$create(as.POSIXct("2022-03-26"))
# it only errors when a is date32() and b is timestamp("s")
a$cast(date32()) - b$cast(timestamp("s"))
#> Error: NotImplemented: Function 'subtract_checked' has no kernel matching
input types (array[date32[day]], array[timestamp[s]])
#> /Users/dragos/Documents/arrow/cpp/src/arrow/compute/function.cc:231
DispatchBest(&inputs)
# it works fine in all other cases
a$cast(date32()) - b$cast(timestamp("ms"))
#> Array
#> <duration[ms]>
#> [
#> -86400000
#> ]
a$cast(date32()) - b$cast(timestamp("us"))
#> Array
#> <duration[us]>
#> [
#> -86400000000
#> ]
a$cast(date32()) - b$cast(timestamp("ns"))
#> Array
#> <duration[ns]>
#> [
#> -86400000000000
#> ]
# a is date64() and b is timestamp()
a$cast(date64()) - b$cast(timestamp("s"))
#> Array
#> <duration[ms]>
#> [
#> -86400000
#> ]
a$cast(date64()) - b$cast(timestamp("ms"))
#> Array
#> <duration[ms]>
#> [
#> -86400000
#> ]
a$cast(date64()) - b$cast(timestamp("us"))
#> Array
#> <duration[us]>
#> [
#> -86400000000
#> ]
a$cast(date64()) - b$cast(timestamp("ns"))
#> Array
#> <duration[ns]>
#> [
#> -86400000000000
#> ]
{code}
--
This message was sent by Atlassian Jira
(v8.20.1#820001)
