Struct PatternID

pub struct PatternID(/* private fields */);

The identifier of a regex pattern, represented by a SmallIndex.

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.

See the SmallIndex type for more information about what it means for a pattern ID to be a “small index.”

Note that this type is defined in the util::primitives module, but it is also re-exported at the crate root due to how common it is.

Implementations

impl PatternID

pub const MAX: PatternID = _

The maximum value.

pub const LIMIT: usize = 2_147_483_647usize

The total number of values that can be represented.

pub const ZERO: PatternID = _

The zero value.

pub const SIZE: usize = 4usize

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

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

Create a new value that is represented by a “small index.”

If the given index exceeds the maximum allowed value, then this returns an error.

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

Create a new value without checking whether the given argument exceeds the maximum.

Using this routine with an invalid value will result in unspecified behavior, but not undefined behavior. In particular, an invalid ID value is likely to cause panics or possibly even silent logical errors.

Callers must never rely on this type to be within a certain range for memory safety.

pub fn must(value: usize) -> PatternID

Like new, but panics if the given value is not valid.

pub const fn as_usize(&self) -> usize

Return the internal value as a usize. This is guaranteed to never overflow usize.

pub const fn as_u64(&self) -> u64

Return the internal value as a u64. This is guaranteed to never overflow.

pub const fn as_u32(&self) -> u32

Return the internal value as a u32. This is guaranteed to never overflow u32.

pub const fn as_i32(&self) -> i32

Return the internal value as a i32. This is guaranteed to never overflow an i32`.

pub fn one_more(&self) -> usize

Returns one more than this value as a usize.

Since values represented by a “small index” have constraints on their maximum value, adding 1 to it will always fit in a usize, u32 and a i32.

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

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

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

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

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

This is analogous to new_unchecked in that is does not check whether the decoded integer is representable as a small index.

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

Return the underlying 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 From<u8> for PatternID

fn from(value: u8) -> PatternID

Converts to this type from the input 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, Self: Sized,

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>

Available on crate feature alloc only.

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>

Available on crate feature alloc only.

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

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,

Restrict a value to a certain interval.

impl PartialEq for PatternID

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

Tests for self and other values to be equal, and is used by ==.

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

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

impl PartialOrd 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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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(value: 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(value: 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(value: u64) -> Result<PatternID, PatternIDError>

Performs the conversion.

impl TryFrom<usize> for PatternID

type Error = PatternIDError

The type returned in the event of a conversion error.

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

Performs the conversion.

impl Copy for PatternID

impl Eq for PatternID

impl StructuralPartialEq for PatternID