Support r# escape syntax in Rust function names in rust_source() …

…family of functions (#374)

* Add test to reproduce the issue

* Update regex

* Cleanup

NEWS.md

@@ -13,6 +13,7 @@
 * Support `RTOOLS44` (#347)
 * Removed `use_try_from` as an option in `rust_function`, and added `use_rng` (#354)
 * Added `use_crate()` function to make adding dependencies to Cargo.toml easier within R, similar to `usethis::use_package()` (#361)
+* Fixed an issue in `rust_source()` family of functions that prevented usage of `r#` escape sequences in Rust function names (#374)
 
 # rextend 0.3.1
 

R/find_exports.R

@@ -25,7 +25,7 @@ extract_meta <- function(lns) {
   # Matches fn|impl<'a> item_name
   result <- stringi::stri_match_first_regex(
     glue_collapse(lns, sep = "\n"),
-    "(?:(fn)|(impl)(?:\\s*<(.+?)>)?)\\s+(_\\w+|[A-z]\\w*)"
+    "(?:(?<fn>fn)|(?<impl>impl)(?:\\s*<(?<lifetime>.+?)>)?)\\s+(?<name>(?:r#)?(?:_\\w+|[A-z]\\w*))"
   ) %>%
     tibble::as_tibble(.name_repair = "minimal") %>%
     rlang::set_names(c("match", "fn", "impl", "lifetime", "name")) %>%

tests/testthat/test-source.R

@@ -130,3 +130,20 @@ test_that("`rust_source()` should not raise internal error for code without exte
 
   expect_no_error(rust_source(code = "fn test() {}"))
 })
+
+# https://github.com/extendr/rextendr/issues/356
+test_that("`rust_function()` supports `r#` prefix in rust function names", {
+  skip_if_cargo_unavailable()
+
+  rust_fn_src <- "
+    fn r#true() -> &'static str {
+        \"Specially-named function has been called\"
+    }
+    "
+
+  rust_function(
+    code = rust_fn_src
+  )
+
+  expect_equal(true(), "Specially-named function has been called")
+})