Struct Repetition

pub struct Repetition {
    pub min: u32,
    pub max: Option<u32>,
    pub greedy: bool,
    pub sub: Box<Hir>,
}

The high-level intermediate representation of a repetition operator.

A repetition operator permits the repetition of an arbitrary sub-expression.

Fields

min: u32

The minimum range of the repetition.

Note that special cases like ?, + and * all get translated into the ranges {0,1}, {1,} and {0,}, respectively.

When min is zero, this expression can match the empty string regardless of what its sub-expression is.

max: Option<u32>

The maximum range of the repetition.

Note that when max is None, min acts as a lower bound but where there is no upper bound. For something like x{5} where the min and max are equivalent, min will be set to 5 and max will be set to Some(5).

greedy: bool

Whether this repetition operator is greedy or not. A greedy operator will match as much as it can. A non-greedy operator will match as little as it can.

Typically, operators are greedy by default and are only non-greedy when a ? suffix is used, e.g., (expr)* is greedy while (expr)*? is not. However, this can be inverted via the U “ungreedy” flag.

sub: Box<Hir>

The expression being repeated.

Implementations

impl Repetition

pub fn with(&self, sub: Hir) -> Repetition

Returns a new repetition with the same min, max and greedy values, but with its sub-expression replaced with the one given.

Trait Implementations

impl Clone for Repetition

fn clone(&self) -> Repetition

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Repetition

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

Formats the value using the given formatter.

impl PartialEq for Repetition

fn eq(&self, other: &Repetition) -> 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 Eq for Repetition

impl StructuralPartialEq for Repetition