Enum Prefix

pub enum Prefix<'a> {
    Empty(SourceSpan),
    Literal(Span<Cow<'a, str>>),
    Substring(Span<Cow<'a, str>>),
    Regex(RegexPattern<'a>),
    Match(Cow<'a, Match<'a>>),
}

A pattern prefix represents the first distinct subpattern of the overall pattern which can be matched independently of the rest of the pattern.

Prefixes are used when constructing sets of patterns to find overlapping prefixes that can be collapsed into more efficient searchers for matching.

Variants

Empty(SourceSpan)

The entire pattern is empty

Literal(Span<Cow<'a, str>>)

The entire pattern is a literal string

Substring(Span<Cow<'a, str>>)

The pattern is a literal string, but only a subset is the prefix

Regex(RegexPattern<'a>)

The prefix is a simple regular expression

Match(Cow<'a, Match<'a>>)

The prefix contains a match block/substitution that cannot be reduced to a regular expression or literal prefix.

Implementations

impl<'a> Prefix<'a>

pub fn as_str(&self) -> Option<&str>

Trait Implementations

impl<'a> Clone for Prefix<'a>

fn clone(&self) -> Prefix<'a>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'a> Ord for Prefix<'a>

fn cmp(&self, other: &Self) -> 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,

Restrict a value to a certain interval.

impl<'a> PartialEq for Prefix<'a>

fn eq(&self, other: &Self) -> 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<'a> PartialOrd for Prefix<'a>

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

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

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl<'a> Spanned for Prefix<'a>

fn span(&self) -> SourceSpan

fn start(&self) -> usize

fn end(&self) -> usize

fn range(&self) -> Range<usize>

impl<'a> Eq for Prefix<'a>