Struct regex::dfa::Transitions

struct Transitions {
    table: Vec<u32>,
    num_byte_classes: usize,
}

The transition table.

It is laid out in row-major order, with states as rows and byte class transitions as columns.

The transition table is responsible for producing valid StatePtrs. A StatePtr points to the start of a particular row in this table. When indexing to find the next state this allows us to avoid a multiplication when computing an index into the table.

Fields

table: Vec<u32>

The table.

num_byte_classes: usize

The stride.

Methods

impl Transitions

fn new(num_byte_classes: usize) -> Transitions

Create a new transition table.

The number of byte classes corresponds to the stride. Every state will have num_byte_classes slots for transitions.

fn num_states(&self) -> usize

Returns the total number of states currently in this table.

fn add(&mut self) -> Option<u32>

Allocates room for one additional state and returns a pointer to it.

If there's no more room, None is returned.

fn clear(&mut self)

Clears the table of all states.

fn set_next(&mut self, si: u32, cls: usize, next: u32)

Sets the transition from (si, cls) to next.

fn next(&self, si: u32, cls: usize) -> u32

Returns the transition corresponding to (si, cls).

fn state_heap_size(&self) -> usize

The heap size, in bytes, of a single state in the transition table.

unsafe fn next_unchecked(&self, si: u32, cls: usize) -> u32

Like next, but uses unchecked access and is therefore unsafe.

Trait Implementations

impl Clone for Transitions

fn clone(&self) -> Transitions

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Transitions

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

Formats the value using the given formatter.