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Revert "Add ByteNeedle search in StrSearcherImpl" - #163557

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pacak wants to merge 5 commits into
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pacak:revert-byte-needle

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@pacak

@pacak pacak commented Sep 30, 2026 •

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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:

Original code had pattern parametrized by a reference (`Pattern<&str>`),
I changed it to be `Pattern<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.
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

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