Struct regex::CaptureLocations

pub struct CaptureLocations(_);

CaptureLocations is a low level representation of the raw offsets of each submatch.

You can think of this as a lower level Captures, where this type does not support named capturing groups directly and it does not borrow the text that these offsets were matched on.

Primarily, this type is useful when using the lower level Regex APIs such as read_captures, which permits amortizing the allocation in which capture match locations are stored.

In order to build a value of this type, you’ll need to call the capture_locations method on the Regex being used to execute the search. The value returned can then be reused in subsequent searches.

Example

This example shows how to create and use CaptureLocations in a search.

use regex::Regex;

let re = Regex::new(r"(?<first>\w+)\s+(?<last>\w+)").unwrap();
let mut locs = re.capture_locations();
let m = re.captures_read(&mut locs, "Bruce Springsteen").unwrap();
assert_eq!(0..17, m.range());
assert_eq!(Some((0, 17)), locs.get(0));
assert_eq!(Some((0, 5)), locs.get(1));
assert_eq!(Some((6, 17)), locs.get(2));

// Asking for an invalid capture group always returns None.
assert_eq!(None, locs.get(3));
assert_eq!(None, locs.get(34973498648));
assert_eq!(None, locs.get(9944060567225171988));

Implementations

impl CaptureLocations

pub fn get(&self, i: usize) -> Option<(usize, usize)>

Returns the start and end positions of the Nth capture group. Returns None if i is not a valid capture group or if the capture group did not match anything. The positions returned are always byte indices with respect to the original string matched.

pub fn len(&self) -> usize

Returns the total number of capture groups (even if they didn’t match).

This is always at least 1 since every regex has at least 1 capturing group that corresponds to the entire match.

Trait Implementations

impl Clone for CaptureLocations

fn clone(&self) -> CaptureLocations

Returns a copy of the value.

const fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for CaptureLocations

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.