Struct regex_automata::dfa::onepass::Transition

struct Transition(u64);

Represents a single transition in a one-pass DFA.

The high 21 bits corresponds to the state ID. The bit following corresponds to the special “match wins” flag. The remaining low 42 bits corresponds to the transition epsilons, which contains the slots that should be saved when this transition is followed and the conditional epsilon transitions that must be satisfied in order to follow this transition.

Tuple Fields

0: u64

Implementations

impl Transition

const STATE_ID_BITS: u64 = 21u64

const STATE_ID_SHIFT: u64 = 43u64

const STATE_ID_LIMIT: u64 = 2_097_152u64

const MATCH_WINS_SHIFT: u64 = 42u64

const INFO_MASK: u64 = 4_398_046_511_103u64

fn new(match_wins: bool, sid: StateID, epsilons: Epsilons) -> Transition

Return a new transition to the given state ID with the given epsilons.

fn is_dead(self) -> bool

Returns true if and only if this transition points to the DEAD state.

fn match_wins(&self) -> bool

Return whether this transition has a “match wins” property.

When a transition has this property, it means that if a match has been found and the search uses leftmost-first semantics, then that match should be returned immediately instead of continuing on.

The “match wins” name comes from RE2, which uses a pretty much identical mechanism for implementing leftmost-first semantics.

fn state_id(&self) -> StateID

Return the “next” state ID that this transition points to.

fn set_state_id(&mut self, sid: StateID)

Set the “next” state ID in this transition.

fn epsilons(&self) -> Epsilons

Return the epsilons embedded in this transition.

Trait Implementations

impl Clone for Transition

fn clone(&self) -> Transition

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Transition

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

Formats the value using the given formatter.

impl PartialEq for Transition

fn eq(&self, other: &Transition) -> 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 Copy for Transition

impl Eq for Transition

impl StructuralPartialEq for Transition