Struct regex_syntax::hir::literal::Literal

pub struct Literal {
    bytes: Vec<u8>,
    exact: bool,
}

A single literal extracted from an Hir expression.

A literal is composed of two things:

• A sequence of bytes. No guarantees with respect to UTF-8 are provided. In particular, even if the regex a literal is extracted from is UTF-8, the literal extracted may not be valid UTF-8. (For example, if an Extractor limit resulted in trimming a literal in a way that splits a codepoint.)
• Whether the literal is “exact” or not. An “exact” literal means that it has not been trimmed, and may continue to be extended. If a literal is “exact” after visiting the entire Hir expression, then this implies that the literal leads to a match state. (Although it doesn’t necessarily imply all occurrences of the literal correspond to a match of the regex, since literal extraction ignores look-around assertions.)

Fields

bytes: Vec<u8>

exact: bool

Implementations

impl Literal

pub fn exact<B: Into<Vec<u8>>>(bytes: B) -> Literal

Returns a new exact literal containing the bytes given.

pub fn inexact<B: Into<Vec<u8>>>(bytes: B) -> Literal

Returns a new inexact literal containing the bytes given.

pub fn as_bytes(&self) -> &[u8]

Returns the bytes in this literal.

pub fn into_bytes(self) -> Vec<u8>

Yields ownership of the bytes inside this literal.

Note that this throws away whether the literal is “exact” or not.

pub fn len(&self) -> usize

Returns the length of this literal in bytes.

pub fn is_empty(&self) -> bool

Returns true if and only if this literal has zero bytes.

pub fn is_exact(&self) -> bool

Returns true if and only if this literal is exact.

pub fn make_inexact(&mut self)

Marks this literal as inexact.

Inexact literals can never be extended. For example, Seq::cross_forward will not extend inexact literals.

pub fn reverse(&mut self)

Reverse the bytes in this literal.

pub fn extend(&mut self, lit: &Literal)

Extend this literal with the literal given.

If this literal is inexact, then this is a no-op.

pub fn keep_first_bytes(&mut self, len: usize)

Trims this literal such that only the first len bytes remain. If this literal has fewer than len bytes, then it remains unchanged. Otherwise, the literal is marked as inexact.

pub fn keep_last_bytes(&mut self, len: usize)

Trims this literal such that only the last len bytes remain. If this literal has fewer than len bytes, then it remains unchanged. Otherwise, the literal is marked as inexact.

fn is_poisonous(&self) -> bool

Returns true if it is believe that this literal is likely to match very frequently, and is thus not a good candidate for a prefilter.

Trait Implementations

impl AsRef<[u8]> for Literal

fn as_ref(&self) -> &[u8]

Converts this type into a shared reference of the (usually inferred) input type.

impl Clone for Literal

fn clone(&self) -> Literal

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Literal

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

Formats the value using the given formatter.

impl From<char> for Literal

fn from(ch: char) -> Literal

Converts to this type from the input type.

impl From<u8> for Literal

fn from(byte: u8) -> Literal

Converts to this type from the input type.

impl FromIterator<Literal> for Seq

fn from_iter<T: IntoIterator<Item = Literal>>(it: T) -> Seq

Creates a value from an iterator.

impl Ord for Literal

fn cmp(&self, other: &Literal) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for Literal

fn eq(&self, other: &Literal) -> 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 PartialOrd for Literal

fn partial_cmp(&self, other: &Literal) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Eq for Literal

impl StructuralPartialEq for Literal