Enum redfa::regex::Regex

pub enum Regex<T> {
    Null,
    Empty,
    Except(Vec<T>),
    Alt(Vec<T>, Vec<Regex<T>>),
    And(Vec<Regex<T>>),
    Not(Box<Regex<T>>),
    Cat(Vec<Regex<T>>),
    Kleene(Box<Regex<T>>),
}

A regular expression over the alphabet T.

Variants

Null

The null set. This never matches anything.

Empty

The empty string (matches exactly “”).

Except(Vec<T>)

Matches any single character except the listed ones.

Alt(Vec<T>, Vec<Regex<T>>)

Alternation (also known as disjunction). Matches any of the contained characters, as well as any string matched by a contained regex.

And(Vec<Regex<T>>)

Conjunction. Matches iff all contained regexes match.

Not(Box<Regex<T>>)

Negation. Matches iff the contained regex does not match.

Cat(Vec<Regex<T>>)

Concatenation. Matches iff the contained regexes match in sequence.

Kleene(Box<Regex<T>>)

Kleene closure. Matches zero or more repetitions of the contained regex.

Implementations

impl<T> Regex<T>

pub fn nullable(&self) -> bool

Tests whether a regular expression is nullable, i.e. whether it matches the empty string.

Examples found in repository

examples/test.rs (line 17)

fn main() {
    let stdin = std::io::stdin();
    for line in stdin.lock().lines() {
        let line = line.unwrap();
        match line.trim().parse::<Regex<char>>() {
            Err(e) => println!("error: {}", e),
            Ok(x) => {
                println!("ok: {:?}", x);
                let x = x.normalize();
                println!("{:?}", x);
                println!("{:?}", x.derivative().map(Normalize::normalize));
                let (dfa, _mapping) = Dfa::from_derivatives(vec![x, Regex::Null]);
                let dfa = dfa.map(|reg| reg.nullable());
                println!("DFA: {:?}\n", dfa);
                let mdfa = dfa.minimize().map(|x| *x);
                println!("Minimized DFA: {:?}\n", mdfa);
                println!("dfa == mdfa: {:?}\n", dfa == mdfa);
            }
        }
    }
}

Trait Implementations

impl<T: Clone> Clone for Regex<T>

fn clone(&self) -> Regex<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for Regex<T>

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

Formats the value using the given formatter.

impl<T: Ord + Clone> Differentiable<T> for Regex<T>

fn derivative(&self) -> Derivatives<T, Regex<T>>

impl FromStr for Regex<char>

fn from_str(s: &str) -> Result<Regex<char>, ParseError>

Parse a string as a regular expression.

type Err = ParseError

The associated error which can be returned from parsing.

impl<T: Ord> Normalize for Regex<T>

fn normalize(self) -> Self

impl<T: Ord> Ord for Regex<T>

fn cmp(&self, other: &Regex<T>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl<T: PartialEq> PartialEq for Regex<T>

fn eq(&self, other: &Regex<T>) -> 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<T: PartialOrd> PartialOrd for Regex<T>

fn partial_cmp(&self, other: &Regex<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T: Eq> Eq for Regex<T>

impl<T> StructuralEq for Regex<T>

impl<T> StructuralPartialEq for Regex<T>