push-wlxvvvxzrsly - #161755
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Right now things are undertested and underspecified. Some of the library code would get in a loop if searcher starts returning empty rejects. And there's no tests for backwards multi byte char matchers. Pull request I'm reviving had a problem implementing that, so making sure it's tested before the actual code lands. Right now it is possible to break both tests (and user code) without breaking anything else in the test suite I think.
Add a Haystack trait describing something that can be searched in and make core::str::Pattern (and related types) generic on that trait. This will allow Pattern to be used for types other than str (most notably OsStr). This somewhat follows the Pattern API 2.0 design. While that design is apparently abandoned (?), it is somewhat helpful when going for patterns on OsStr, so I’m going with it unless someone tells me otherwise. ;) For now leave Pattern, Haystack et al in core::str::pattern. Since they are no longer str-specific, I’ll move them to core::pattern in future commit. This one leaves them in place to make the diff smaller. @pacak: I moved some (or all new) of the `P: Pattern<&'a str> constraints into where clause to keep things narrower: ``` pub fn foo<'a, P: Pattern<&'a str>>(&'a self, pat: P, ...) ... ``` to ``` pub fn replacen<'a, P>(&'a self, pat: P, ...) ... where P: Pattern<&'a str>, ``` Original code had indices in Haystack abstracted as an associated type Cursor. Replaced with usize - Cursor adds noise with not much value. Changed wording in 2-3 places - for example Searcher is generic over a few types so it makes more sense to talk about split points in general with utf8 split points as an example for `&str`.
Pattern is no longer str-specific, so move it from core::str::pattern module to a new core::pattern module. This introduces no changes in behaviour or implementation. Just moves stuff around and adjusts documentation.
Introduce core::pattern::Split and core::pattern::SplitN internal types which can be used to implement iterators splitting haystack into parts. Convert str’s Split-family of iterators to use them. In the future, more haystacks will use those internal types. Co-authored-by: Peter Jaszkowiak <p.jaszkow@gmail.com> @pacak: Fixed some typos, added a few `#[inline]`. Since there's no `H::Cursor` - I had to add `ctx: PhantomData<H>`.
This reverts commit 85cf233ced0d0fe02734c8a83b6d79ccc5432d06. Gone for now, I'll reimplement it later in str_bytes.rs, will confirm with the benchmarks included that the optimization still applies
Introduce core::pattern::EmptyNeedleSearcher internal type which implements logic for matching an empty pattern against a haystack. Convert core::str::pattern::StrSearcher to use it. In future more implementations will take advantage of it. Also adapt and rework TwoWayStrategy into an internal SearchResult trait which abstracts differences between Searcher’s next, next_match and next_rejects methods. It makes it simpler to write a single generic method implementing optimised versions of all those calls. @pacak: - Fixed a few typos. - There's no H::Cursor parameter so code gets a bit simplified. - Added a test to assert how TwoWaySearcher runs with EmptyNeedleSearcher
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This was referenced Aug 25, 2026
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fa667f5ecore: add core::pattern::EmptyNeedleSearcher internal typeIntroduce core::pattern::EmptyNeedleSearcher internal type which
implements logic for matching an empty pattern against a haystack.
Convert core::str::pattern::StrSearcher to use it. In future more
implementations will take advantage of it.
Also adapt and rework TwoWayStrategy into an internal SearchResult
trait which abstracts differences between Searcher’s next, next_match
and next_rejects methods. It makes it simpler to write a single generic
method implementing optimised versions of all those calls.
@pacak:\
EmptyNeedleSearcher
e9f97dd3Revert "Add ByteNeedle search in StrSearcherImpl"This reverts commit 85cf233ced0d0fe02734c8a83b6d79ccc5432d06.
Gone for now, I'll reimplement it later in str_bytes.rs, will confirm
with the benchmarks included that the optimization still applies
This PR is part of a stack containing 16 PRs:
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