thisisnic commented on a change in pull request #11105:
URL: https://github.com/apache/arrow/pull/11105#discussion_r710985582
##########
File path: r/R/dplyr-functions.R
##########
@@ -672,6 +672,16 @@ nse_funcs$strptime <- function(x, format = "%Y-%m-%d
%H:%M:%S", tz = NULL, unit
Expression$create("strptime", x, options = list(format = format, unit =
unit))
}
+nse_funcs$strftime <- function(x, format = "", tz = "", usetz = FALSE) {
+ if (tz != "") {
+ arrow_not_supported("tz argument")
Review comment:
Is it possible? Maybe. Here's the steps I'd take to find out:
1. Open R, load Arrow, and call `list_compute_functions()` to get a list of
compute kernels available from R. I see "cast" is there, so this looks
promising. Alternatively, I could start by looking at the C++ compute kernels
documentation to see if there are any fitting kernels.
2. Open `arrow/r/src/compute.cpp` to check if the `cast` kernel has its
options bound and if so, what are they. It does, and the key one here is
`to_type`.
3. Play around with `call_function()` (R function you can use for directly
calling compute kernels to test things etc). I ended up with this example
working for me: `call_function("cast", Array$create(c(1:3L)), options =
list(to_type = utf8()))`. Not the simil
4. I'm pretty sure we can have Expressions which take other Expressions as
arguments, I've implemented things with this in the past, though there are no
current code examples, so I'd experiment with that. Here's an example using
`call_function()` which could be analogous to how it works with Expressions:
```
call_function(
"replace_substring",
call_function(
"cast",
Array$create(c(1:3L)),
options = list(to_type = utf8())
),
options = list(pattern = "1", replacement = "one")
)
```
Should we do it? I *think* so, though I'm a bit hesitant to say "yes" as
I'm concerned about unintended consequences or inconsistencies. But then
again, I guess that's what unit tests are for, right? ;)
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