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https://issues.apache.org/jira/browse/ARROW-16060?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Rok Mihevc reassigned ARROW-16060:
----------------------------------
Assignee: Rok Mihevc
> [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
> Assignee: Rok Mihevc
> Priority: Critical
>
> 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}
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