Struct ExprInfo

pub struct ExprInfo {
    pub min_width: ExprWidth,
    pub max_width: Option<ExprWidth>,
    pub unordered_matches: UnorderedMatchBehavior,
    pub matches_at_eod: MatchAtEndBehavior,
}

Available on crate feature compiler only.

Data produced by vectorscan to analyze a particular expression.

This struct is produced by super::Expression::info():

 use vectorscan::{expression::{*, info::*}, flags::Flags};

 let expr: Expression = "(he)llo$".parse()?;
 let info = expr.info(Flags::default())?;
 assert_eq!(info, ExprInfo {
   min_width: ExprWidth(5),
   max_width: Some(ExprWidth(5)),
   unordered_matches: UnorderedMatchBehavior::AllowsUnordered,
   matches_at_eod: MatchAtEndBehavior::WillOnlyMatchAtEOD,
 });

as well as super::Expression::ext_info():

 use vectorscan::{expression::{*, info::*}, flags::Flags};

 let expr: Expression = ".*lo($)?".parse()?;
 let ext = ExprExt::from_min_length(4);
 let info = expr.ext_info(Flags::default(), &ext)?;
 assert_eq!(info, ExprInfo {
   min_width: ExprWidth(4),
   max_width: None,
   unordered_matches: UnorderedMatchBehavior::AllowsUnordered,
   matches_at_eod: MatchAtEndBehavior::MayMatchAtEOD,
 });

Fields

min_width: ExprWidth

The minimum length in bytes of a match for the pattern. If the pattern has an unbounded minimum length, this will be 0.

Note: in some cases when using advanced features to suppress matches (such as extended parameters or Flags::SINGLEMATCH) this may represent a conservative lower bound for the true minimum length of a match.

max_width: Option<ExprWidth>

The maximum length in bytes of a match for the pattern. If the pattern has an unbounded maximum length, this will be None.

Note: in some cases when using advanced features to suppress matches (such as extended parameters or Flags::SINGLEMATCH) this may represent a conservative upper bound for the true maximum length of a match.

unordered_matches: UnorderedMatchBehavior

Whether this expression can produce matches that are not returned in order, such as those produced by assertions.

matches_at_eod: MatchAtEndBehavior

Whether this expression can produce matches at end of data (EOD).

In streaming mode, EOD matches are raised during Scratch::flush_eod_sync() or Scratch::flush_eod_sync(), since it is only when flush_eod() is called that the EOD location is known.

Note: trailing \b word boundary assertions may also result in EOD matches as end-of-data can act as a word boundary.

Trait Implementations

impl Clone for ExprInfo

fn clone(&self) -> ExprInfo

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ExprInfo

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

Formats the value using the given formatter.

impl Hash for ExprInfo

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for ExprInfo

fn cmp(&self, other: &ExprInfo) -> 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 PartialEq for ExprInfo

fn eq(&self, other: &ExprInfo) -> 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 PartialOrd for ExprInfo

fn partial_cmp(&self, other: &ExprInfo) -> 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 Copy for ExprInfo

impl Eq for ExprInfo

impl StructuralPartialEq for ExprInfo