Unnamed repository; edit this file 'description' to name the repository.
| -rw-r--r-- | lib/smol_str/CHANGELOG.md | 2 | ||||
| -rw-r--r-- | lib/smol_str/src/lib.rs | 29 |
2 files changed, 16 insertions, 15 deletions
diff --git a/lib/smol_str/CHANGELOG.md b/lib/smol_str/CHANGELOG.md index c0193f6fcb..1dff469b8a 100644 --- a/lib/smol_str/CHANGELOG.md +++ b/lib/smol_str/CHANGELOG.md @@ -6,7 +6,7 @@ ~2x speedup inline, ~4-22x for heap. - Optimise `StrExt::to_lowercase_smolstr`, `StrExt::to_uppercase_smolstr` ~2x speedup inline, ~5-50x for heap. - Optimise `StrExt::replace_smolstr`, `StrExt::replacen_smolstr` for single ascii replace. - ~3x speedup inline, ~1.8x for heap (len=50). + ~3.7x speedup inline, ~2.4x for heap. ## 0.3.2 - 2024-10-23 diff --git a/lib/smol_str/src/lib.rs b/lib/smol_str/src/lib.rs index d55ba20522..3a6442eaab 100644 --- a/lib/smol_str/src/lib.rs +++ b/lib/smol_str/src/lib.rs @@ -714,11 +714,21 @@ impl StrExt for str { } #[inline] - fn replacen_smolstr(&self, from: &str, to: &str, count: usize) -> SmolStr { + fn replacen_smolstr(&self, from: &str, to: &str, mut count: usize) -> SmolStr { // Fast path for replacing a single ASCII character with another inline. if let [from_u8] = from.as_bytes() { if let [to_u8] = to.as_bytes() { - return replacen_1_ascii(self, *from_u8, *to_u8, count); + return match self.len() <= count { + true => replacen_1_ascii(self, |b| if b == *from_u8 { *to_u8 } else { b }), + _ => replacen_1_ascii(self, |b| { + if b == *from_u8 && count != 0 { + count -= 1; + *to_u8 + } else { + b + } + }), + }; } } @@ -739,20 +749,11 @@ impl StrExt for str { } #[inline] -fn replacen_1_ascii(src: &str, from: u8, to: u8, count: usize) -> SmolStr { - let mut replaced = 0; - let mut ascii_replace = |b: &u8| { - if *b == from && replaced != count { - replaced += 1; - to - } else { - *b - } - }; +fn replacen_1_ascii(src: &str, mut map: impl FnMut(u8) -> u8) -> SmolStr { if src.len() <= INLINE_CAP { let mut buf = [0u8; INLINE_CAP]; for (idx, b) in src.as_bytes().iter().enumerate() { - buf[idx] = ascii_replace(b); + buf[idx] = map(*b); } SmolStr(Repr::Inline { // SAFETY: `len` is in bounds @@ -760,7 +761,7 @@ fn replacen_1_ascii(src: &str, from: u8, to: u8, count: usize) -> SmolStr { buf, }) } else { - let out = src.as_bytes().iter().map(ascii_replace).collect(); + let out = src.as_bytes().iter().map(|b| map(*b)).collect(); // SAFETY: We replaced ascii with ascii on valid utf8 strings. unsafe { String::from_utf8_unchecked(out).into() } } |