Struct peepmatic_automata::Query

pub struct Query<'a, TAlphabet, TState, TOutput> where
    TAlphabet: Clone + Eq + Hash + Ord,
    TState: Clone + Eq + Hash,
    TOutput: Output,  { /* fields omitted */ }

A low-level query of an Automaton.

This allows you to incrementally query an Automaton, without providing the full input sequence ahead of time, and also to incrementally build up the output.

The typical usage pattern is:

• First, a series of next calls that each provide one character of the input sequence.

  If this query is still on a path towards a known entry of the automata, then Some is returned with the partial output of the transition that was just taken. Otherwise, None is returned, signifying that the input string has been rejected by the automata.

  You may also inspect the current state’s associated custom data, if any, in between next calls via the current_state_data method.

• When the input sequence is exhausted, call is_in_final_state to determine if this query is in a final state of the automata. If it is not, then the input string has been rejected by the automata.

• Given that the input sequence is exhausted, you may call finish to get the final bit of partial output.

Implementations

impl<'a, TAlphabet, TState, TOutput> Query<'a, TAlphabet, TState, TOutput> where
    TAlphabet: Clone + Eq + Hash + Ord,
    TState: Clone + Eq + Hash,
    TOutput: Output, 

pub fn current_state(&self) -> State

Get the current state in the automaton that this query is at.

pub fn go_to_state(&mut self, state: State)

Move this query to the given state in the automaton.

This can be used to implement backtracking, if you can also reset your output to the way it was when you previously visited the given State.

Only use a State that came from this query’s automaton! Mixing and matching states between automata will result in bogus results and/or panics!

pub fn has_transition_on(&self, input: &TAlphabet) -> bool

Does the query’s current state have a transition on the given input?

Regardless whether a transition on the given input exists for the current state or not, the query remains in the current state.

pub fn next(&mut self, input: &TAlphabet) -> Option<&'a TOutput>

Transition to the next state given the next input character, and return the partial output for that transition.

If None is returned, then the input sequence has been rejected by the automata, and this query remains in its current state.

pub fn current_state_data(&self) -> Option<&'a TState>

Get the current state’s associated custom data, if any.

See also InsertionBuilder::set_state_data.

pub fn is_in_final_state(&self) -> bool

Is this query currently in a final state?

pub fn finish(self) -> Option<&'a TOutput>

Given that the input sequence is exhausted, get the final bit of partial output.

Returns None if this query is not currently in a final state, meaning that the automata has rejected this input sequence. You can check whether that is the case or not with the is_in_final_state method.

Trait Implementations

impl<'a, TAlphabet: Clone, TState: Clone, TOutput: Clone> Clone for Query<'a, TAlphabet, TState, TOutput> where
    TAlphabet: Clone + Eq + Hash + Ord,
    TState: Clone + Eq + Hash,
    TOutput: Output, 

fn clone(&self) -> Query<'a, TAlphabet, TState, TOutput>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'a, TAlphabet: Debug, TState: Debug, TOutput: Debug> Debug for Query<'a, TAlphabet, TState, TOutput> where
    TAlphabet: Clone + Eq + Hash + Ord,
    TState: Clone + Eq + Hash,
    TOutput: Output, 

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

Formats the value using the given formatter.