This is an automated email from the ASF dual-hosted git repository.
thisisnic pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/arrow-cookbook.git
The following commit(s) were added to refs/heads/main by this push:
new 49c53df ARROW-13749: [Doc][Cookbook] Work with functions from other
packages via dplyr bindings - R (#95)
49c53df is described below
commit 49c53df06570802867a737e785d0b255e50653ae
Author: Nic Crane <[email protected]>
AuthorDate: Wed Nov 3 10:06:05 2021 +0000
ARROW-13749: [Doc][Cookbook] Work with functions from other packages via
dplyr bindings - R (#95)
* Add content on using functions from other packages
* Add links to packages
---
r/content/tables.Rmd | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/r/content/tables.Rmd b/r/content/tables.Rmd
index 76ea0db..8f46f4d 100644
--- a/r/content/tables.Rmd
+++ b/r/content/tables.Rmd
@@ -146,6 +146,13 @@ If you find any base R or tidyverse functions which you
would like to see a
mapping of in arrow, please
[open an issue on the project
JIRA](https://issues.apache.org/jira/projects/ARROW/issues).
+The following packages (amongst some from others) have had many function
+bindings/mappings written in arrow:
+
+* [lubridate](https://lubridate.tidyverse.org/)
+* [stringr](https://stringr.tidyverse.org/)
+* [dplyr](https://dplyr.tidyverse.org/)
+
If you try to call a function which does not have arrow mapping, the data will
be pulled back into R, and you will see a warning message.
@@ -171,6 +178,39 @@ test_that("dplyr_func_warning", {
})
```
+
+It should be noted that to work with functions which do have mappings, you
must
+refer to them by
+their function names. If you use the `package::function()` syntax, this will
+result in a warning about the data being pulled back into R before the output
is
+calculated.
+
+```{r, dplyr_str_to_lower_r, warning=TRUE}
+Table$create(starwars) %>%
+ select(name) %>%
+ mutate(name_lower = stringr::str_to_lower(name)) %>%
+ head() %>%
+ collect()
+```
+
+```{r, test_dplyr_str_to_lower_r, opts.label = "test"}
+
+test_that("dplyr_str_to_lower_r", {
+
+ expect_warning(
+ Table$create(starwars) %>%
+ select(name) %>%
+ mutate(name_lower = stringr::str_to_lower(name)) %>%
+ head() %>%
+ collect(),
+ "Expression stringr::str_to_lower(name) not supported in Arrow; pulling
data into R",
+ fixed = TRUE
+ )
+
+})
+
+```
+
## Use arrow functions in dplyr verbs in arrow
You want to use a function which is implemented in Arrow's C++ library but
either:
