Struct regex_automata::PatternID

#[repr(transparent)]
pub struct PatternID(_);

An identifier for a regex pattern.

The identifier for a pattern corresponds to its relative position among other patterns in a single finite state machine. Namely, when building a multi-pattern regex engine, one must supply a sequence of patterns to match. The position (starting at 0) of each pattern in that sequence represents its identifier. This identifier is in turn used to identify and report matches of that pattern in various APIs.

A pattern ID is guaranteed to be representable by a usize. Similarly, the number of patterns in any regex engine in this crate is guaranteed to be representable by a usize. This applies to regex engines that have been deserialized; a deserialization error will be returned if it contains pattern IDs that violate these requirements in your current environment.

For extra convenience in some cases, this type also guarantees that all IDs can fit into an i32 and an isize without overflowing.

Representation

This type is always represented internally by a u32 and is marked as repr(transparent). Thus, this type always has the same representation as a u32.

Indexing

For convenience, callers may use a PatternID to index slices.

Safety

While a PatternID is meant to guarantee that its value fits into usize (while using a possibly smaller representation than usize on some targets), callers must not rely on this property for safety. Callers may choose to rely on this property for correctness however.

Implementations

impl PatternID

pub const MAX: PatternID

The maximum pattern ID value, represented as a usize.

pub const LIMIT: usize

The total number of patterns that are allowed in any single regex engine.

pub const ZERO: PatternID

The zero pattern ID value.

pub const SIZE: usize

The number of bytes that a single PatternID uses in memory.

pub fn new(id: usize) -> Result<PatternID, PatternIDError>

Create a new pattern ID.

If the given identifier exceeds PatternID::MAX, then this returns an error.

pub const fn new_unchecked(id: usize) -> PatternID

Create a new pattern ID without checking whether the given value exceeds PatternID::MAX.

While this is unchecked, providing an incorrect value must never sacrifice memory safety, as documented above.

pub fn must(id: usize) -> PatternID

Like PatternID::new, but panics if the given ID is not valid.

pub const fn as_usize(&self) -> usize

Return this pattern ID as a usize.

pub const fn as_u32(&self) -> u32

Return the internal u32 of this pattern ID.

pub const fn as_i32(&self) -> i32

Return the internal u32 of this pattern ID represented as an i32.

This is guaranteed to never overflow an i32.

pub fn one_more(&self) -> usize

Returns one more than this pattern ID as a usize.

Since a pattern ID has constraints on its maximum value, adding 1 to it will always fit in a usize (and a u32).

pub fn from_ne_bytes(bytes: [u8; 4]) -> Result<PatternID, PatternIDError>

Decode this pattern ID from the bytes given using the native endian byte order for the current target.

If the decoded integer is not representable as a pattern ID for the current target, then this returns an error.

pub fn from_ne_bytes_unchecked(bytes: [u8; 4]) -> PatternID

Decode this pattern ID from the bytes given using the native endian byte order for the current target.

This is analogous to PatternID::new_unchecked in that is does not check whether the decoded integer is representable as a pattern ID.

pub fn to_ne_bytes(&self) -> [u8; 4]

Return the underlying pattern ID integer as raw bytes in native endian format.

Trait Implementations

impl Clone for PatternID

fn clone(&self) -> PatternID

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for PatternID

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

Formats the value using the given formatter.

impl Default for PatternID

fn default() -> PatternID

Returns the “default value” for a type.

impl Hash for PatternID

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, 

Feeds a slice of this type into the given Hasher.

impl<T> Index<PatternID> for [T]

type Output = T

The returned type after indexing.

fn index(&self, index: PatternID) -> &T

Performs the indexing (container[index]) operation.

impl<T> Index<PatternID> for Vec<T>

type Output = T

The returned type after indexing.

fn index(&self, index: PatternID) -> &T

Performs the indexing (container[index]) operation.

impl<T> IndexMut<PatternID> for [T]

fn index_mut(&mut self, index: PatternID) -> &mut T

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

impl<T> IndexMut<PatternID> for Vec<T>

fn index_mut(&mut self, index: PatternID) -> &mut T

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

impl Ord for PatternID

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

This method returns an Ordering between self and other.

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

Compares and returns the maximum of two values.

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

Compares and returns the minimum of two values.

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

Restrict a value to a certain interval.

impl PartialEq<PatternID> for PatternID

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

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

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

This method tests for !=.

impl PartialOrd<PatternID> for PatternID

fn partial_cmp(&self, other: &PatternID) -> 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 TryFrom<u16> for PatternID

type Error = PatternIDError

The type returned in the event of a conversion error.

fn try_from(id: u16) -> Result<PatternID, PatternIDError>

Performs the conversion.

impl TryFrom<u32> for PatternID

type Error = PatternIDError

The type returned in the event of a conversion error.

fn try_from(id: u32) -> Result<PatternID, PatternIDError>

Performs the conversion.

impl TryFrom<u64> for PatternID

type Error = PatternIDError

The type returned in the event of a conversion error.

fn try_from(id: u64) -> Result<PatternID, PatternIDError>

Performs the conversion.

impl TryFrom<u8> for PatternID

type Error = Infallible

The type returned in the event of a conversion error.

fn try_from(id: u8) -> Result<PatternID, Infallible>

Performs the conversion.

impl TryFrom<usize> for PatternID

type Error = PatternIDError

The type returned in the event of a conversion error.

fn try_from(id: usize) -> Result<PatternID, PatternIDError>

Performs the conversion.

impl Copy for PatternID

impl Eq for PatternID

impl StructuralEq for PatternID

impl StructuralPartialEq for PatternID