Struct aho_corasick::util::special::Special

pub(crate) struct Special {
    pub(crate) max_special_id: StateID,
    pub(crate) max_match_id: StateID,
    pub(crate) start_unanchored_id: StateID,
    pub(crate) start_anchored_id: StateID,
}

A collection of sentinel state IDs for Aho-Corasick automata.

This specifically enables the technique by which we determine which states are dead, matches or start states. Namely, by arranging states in a particular order, we can determine the type of a state simply by looking at its ID.

Fields

max_special_id: StateID

The maximum ID of all the “special” states. This corresponds either to start_anchored_id when a prefilter is active and max_match_id when a prefilter is not active. The idea here is that if there is no prefilter, then there is no point in treating start states as special.

max_match_id: StateID

The maximum ID of all the match states. Any state ID bigger than this is guaranteed to be a non-match ID.

It is possible and legal for max_match_id to be equal to start_anchored_id, which occurs precisely in the case where the empty string is a pattern that was added to the underlying automaton.

start_unanchored_id: StateID

The state ID of the start state used for unanchored searches.

start_anchored_id: StateID

The state ID of the start state used for anchored searches. This is always start_unanchored_id+1.

Implementations

impl Special

pub(crate) fn zero() -> Special

Create a new set of “special” state IDs with all IDs initialized to zero. The general idea here is that they will be updated and set to correct values later.

Trait Implementations

impl Clone for Special

fn clone(&self) -> Special

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Special

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

Formats the value using the given formatter.