[ARROW-16060] [C++] subtract_checked support for timestamp("s") and date32

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: 8.0.0
• Component/s: C++
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/31476
• Assignee: Rok Mihevc
• Reporter: Dragoș Moldovan-Grünfeld
• Created: 29/Mar/22 12:39
• Updated: 11/Jan/23 11:41
• Resolved: 05/Apr/22 14:37

Description

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:

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
#> ]

Issue Links

• links to: GitHub Pull Request #12774