Struct parol::analysis::lookahead_dfa::LookaheadDFA

pub struct LookaheadDFA {
    pub states: Vec<DFAState>,
    pub transitions: BTreeMap<StateIndex, BTreeMap<TerminalIndex, StateIndex>>,
    pub k: usize,
}

The lookahead DFA. Used to calculate a certain production number from a sequence of terminals.

The start state is per definition always the state with index 0.

Fields

states: Vec<DFAState>

DFA states

transitions: BTreeMap<StateIndex, BTreeMap<TerminalIndex, StateIndex>>

The transitions data is the relation: “from-state -> terminal -> to-state” Actually a map of from-states to terminal transitions, which in turn are maps from terminals to to-states.

k: usize

Maximum number of tokens needed to reach an accepting state It is equivalent to the maximum length over all contributing k-tuples.

Implementations

impl LookaheadDFA

pub fn from_k_tuples(k_tuples: &KTuples, prod_num: usize) -> Self

Create a DFA from KTuples The idea is to convert lists of terminals into a trie data structure

pub fn union(&self, other: &Self) -> Result<Self>

Returns the union of self and other without changing self. If there exists a conflict in the accepting states production numbers an error is returned.

pub fn unite(self, other: &Self) -> Result<Self>

Returns the union of self and other while consuming self. If there exists a conflict in the accepting state’s production numbers an error is returned.

Trait Implementations

impl Clone for LookaheadDFA

fn clone(&self) -> LookaheadDFA

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for LookaheadDFA

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

Formats the value using the given formatter.

impl Default for LookaheadDFA

fn default() -> LookaheadDFA

Returns the “default value” for a type.

impl Display for LookaheadDFA

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

Formats the value using the given formatter.

impl PartialEq for LookaheadDFA

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

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

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

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

impl Eq for LookaheadDFA

impl StructuralPartialEq for LookaheadDFA