Trait Haystack 

pub trait Haystack: Copy + Clone {
    type Cursor: HaystackCursor;

    // Required methods
    fn len(&self) -> usize;
    fn cursor_at(&self, pos: usize) -> Self::Cursor;
    fn char_at(&self, pos: usize) -> Option<(char, usize)>;
    fn char_before(&self, pos: usize) -> Option<char>;
    fn starts_with(&self, pos: usize, literal: &str) -> bool;
    fn matches_range(
        &self,
        pos: usize,
        other_start: usize,
        other_end: usize,
    ) -> bool;
    fn find_byte(&self, byte: u8, pos: usize) -> Option<usize>;

    // Provided method
    fn is_empty(&self) -> bool { ... }
}

A trait for text that can be searched by the regex engine. This abstraction allows searching over non-contiguous memory (like ropes) without flattening to a single string.

Required Associated Types

type Cursor: HaystackCursor

Required Methods

fn len(&self) -> usize

Total length of the haystack in bytes

fn cursor_at(&self, pos: usize) -> Self::Cursor

Get a cursor for streaming access starting at pos

fn char_at(&self, pos: usize) -> Option<(char, usize)>

Get character at position

fn char_before(&self, pos: usize) -> Option<char>

Get character before position

fn starts_with(&self, pos: usize, literal: &str) -> bool

Check if haystack starts with literal at pos

fn matches_range( &self, pos: usize, other_start: usize, other_end: usize, ) -> bool

Check if range matches another range

fn find_byte(&self, byte: u8, pos: usize) -> Option<usize>

Find the first occurrence of a byte starting at pos. Returns None if not found.

Provided Methods

fn is_empty(&self) -> bool

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<'a> Haystack for &'a str

type Cursor = StrCursor<'a>

fn len(&self) -> usize

fn char_at(&self, pos: usize) -> Option<(char, usize)>

fn char_before(&self, pos: usize) -> Option<char>

fn starts_with(&self, pos: usize, literal: &str) -> bool

fn matches_range( &self, pos: usize, other_start: usize, other_end: usize, ) -> bool

fn cursor_at(&self, pos: usize) -> Self::Cursor

fn find_byte(&self, byte: u8, pos: usize) -> Option<usize>

Implementors