bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/stdx/src/lib.rs')
-rw-r--r--crates/stdx/src/lib.rs44
1 files changed, 41 insertions, 3 deletions
diff --git a/crates/stdx/src/lib.rs b/crates/stdx/src/lib.rs
index 978c50d807..5fa0074163 100644
--- a/crates/stdx/src/lib.rs
+++ b/crates/stdx/src/lib.rs
@@ -187,11 +187,19 @@ pub fn is_upper_snake_case(s: &str) -> bool {
}
pub fn replace(buf: &mut String, from: char, to: &str) {
- if !buf.contains(from) {
+ let replace_count = buf.chars().filter(|&ch| ch == from).count();
+ if replace_count == 0 {
return;
}
- // FIXME: do this in place.
- *buf = buf.replace(from, to);
+ let from_len = from.len_utf8();
+ let additional = to.len().saturating_sub(from_len);
+ buf.reserve(additional * replace_count);
+
+ let mut end = buf.len();
+ while let Some(i) = buf[..end].rfind(from) {
+ buf.replace_range(i..i + from_len, to);
+ end = i;
+ }
}
#[must_use]
@@ -343,4 +351,34 @@ mod tests {
"fn main() {\n return 92;\n}\n"
);
}
+
+ #[test]
+ fn test_replace() {
+ #[track_caller]
+ fn test_replace(src: &str, from: char, to: &str, expected: &str) {
+ let mut s = src.to_owned();
+ replace(&mut s, from, to);
+ assert_eq!(s, expected, "from: {from:?}, to: {to:?}");
+ }
+
+ test_replace("", 'a', "b", "");
+ test_replace("", 'a', "😀", "");
+ test_replace("", '😀', "a", "");
+ test_replace("a", 'a', "b", "b");
+ test_replace("aa", 'a', "b", "bb");
+ test_replace("ada", 'a', "b", "bdb");
+ test_replace("a", 'a', "😀", "😀");
+ test_replace("😀", '😀', "a", "a");
+ test_replace("😀x", '😀', "a", "ax");
+ test_replace("y😀x", '😀', "a", "yax");
+ test_replace("a,b,c", ',', ".", "a.b.c");
+ test_replace("a,b,c", ',', "..", "a..b..c");
+ test_replace("a.b.c", '.', "..", "a..b..c");
+ test_replace("a.b.c", '.', "..", "a..b..c");
+ test_replace("a😀b😀c", '😀', ".", "a.b.c");
+ test_replace("a.b.c", '.', "😀", "a😀b😀c");
+ test_replace("a.b.c", '.', "😀😀", "a😀😀b😀😀c");
+ test_replace(".a.b.c.", '.', "()", "()a()b()c()");
+ test_replace(".a.b.c.", '.', "", "abc");
+ }
}