Struct regex_automata::Span

pub struct Span {
    pub start: usize,
    pub end: usize,
}

A representation of a span reported by a regex engine.

A span corresponds to the starting and ending byte offsets of a contiguous region of bytes. The starting offset is inclusive while the ending offset is exclusive. That is, a span is a half-open interval.

A span is used to report the offsets of a match, but it is also used to convey which region of a haystack should be searched via routines like Input::span.

This is basically equivalent to a std::ops::Range<usize>, except this type implements Copy which makes it more ergonomic to use in the context of this crate. Like a range, this implements Index for [u8] and str, and IndexMut for [u8]. For convenience, this also impls From<Range>, which means things like Span::from(5..10) work.

Fields

start: usize

The start offset of the span, inclusive.

end: usize

The end offset of the span, exclusive.

Implementations

impl Span

pub fn range(&self) -> Range<usize>

Returns this span as a range.

pub fn is_empty(&self) -> bool

Returns true when this span is empty. That is, when start >= end.

pub fn len(&self) -> usize

Returns the length of this span.

This returns 0 in precisely the cases that is_empty returns true.

pub fn contains(&self, offset: usize) -> bool

Returns true when the given offset is contained within this span.

Note that an empty span contains no offsets and will always return false.

pub fn offset(&self, offset: usize) -> Span

Returns a new span with offset added to this span’s start and end values.

Trait Implementations

impl Clone for Span

fn clone(&self) -> Span

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Span

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

Formats the value using the given formatter.

impl From<Range<usize>> for Span

fn from(range: Range<usize>) -> Span

Converts to this type from the input type.

impl From<Span> for Range<usize>

fn from(span: Span) -> Range<usize>

Converts to this type from the input type.

impl Hash for Span

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Index<Span> for [u8]

type Output = [u8]

The returned type after indexing.

fn index(&self, index: Span) -> &[u8]

Performs the indexing (container[index]) operation.

impl Index<Span> for str

type Output = str

The returned type after indexing.

fn index(&self, index: Span) -> &str

Performs the indexing (container[index]) operation.

impl IndexMut<Span> for [u8]

fn index_mut(&mut self, index: Span) -> &mut [u8]

Performs the mutable indexing (container[index]) operation.

impl PartialEq<Range<usize>> for Span

fn eq(&self, range: &Range<usize>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<Span> for Range<usize>

fn eq(&self, span: &Span) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq for Span

fn eq(&self, other: &Span) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Span

impl Eq for Span

impl StructuralEq for Span

impl StructuralPartialEq for Span