pub struct LookSet {
pub bits: u32,
}Expand description
LookSet is a memory-efficient set of look-around assertions.
This is useful for efficiently tracking look-around assertions. For
example, a thompson::NFA provides properties
that return LookSets.
Fields§
§bits: u32The underlying representation this set is exposed to make it possible
to store it somewhere efficiently. The representation is that
of a bitset, where each assertion occupies bit i where
i = Look::as_repr().
Note that users of this internal representation must permit the full
range of u16 values to be represented. For example, even if the
current implementation only makes use of the 10 least significant bits,
it may use more bits in a future semver compatible release.
Implementations§
Source§impl LookSet
impl LookSet
Sourcepub fn full() -> LookSet
pub fn full() -> LookSet
Create a full set of look-around assertions.
This set contains all possible look-around assertions.
Sourcepub fn singleton(look: Look) -> LookSet
pub fn singleton(look: Look) -> LookSet
Create a look-around set containing the look-around assertion given.
This is a convenience routine for creating an empty set and inserting one look-around assertions.
Sourcepub fn contains(self, look: Look) -> bool
pub fn contains(self, look: Look) -> bool
Returns true if and only if the given look-around assertion is in this set.
Sourcepub fn contains_anchor(&self) -> bool
pub fn contains_anchor(&self) -> bool
Returns true if and only if this set contains any anchor assertions. This includes both “start/end of haystack” and “start/end of line.”
Sourcepub fn contains_anchor_haystack(&self) -> bool
pub fn contains_anchor_haystack(&self) -> bool
Returns true if and only if this set contains any “start/end of haystack” anchors. This doesn’t include “start/end of line” anchors.
Sourcepub fn contains_anchor_line(&self) -> bool
pub fn contains_anchor_line(&self) -> bool
Returns true if and only if this set contains any “start/end of line”
anchors. This doesn’t include “start/end of haystack” anchors. This
includes both \n line anchors and CRLF (\r\n) aware line anchors.
Sourcepub fn contains_anchor_lf(&self) -> bool
pub fn contains_anchor_lf(&self) -> bool
Returns true if and only if this set contains any “start/end of line”
anchors that only treat \n as line terminators. This does not include
haystack anchors or CRLF aware line anchors.
Sourcepub fn contains_anchor_crlf(&self) -> bool
pub fn contains_anchor_crlf(&self) -> bool
Returns true if and only if this set contains any “start/end of line” anchors that are CRLF-aware. This doesn’t include “start/end of haystack” or “start/end of line-feed” anchors.
Sourcepub fn contains_word(self) -> bool
pub fn contains_word(self) -> bool
Returns true if and only if this set contains any word boundary or negated word boundary assertions. This include both Unicode and ASCII word boundaries.
Sourcepub fn contains_word_unicode(self) -> bool
pub fn contains_word_unicode(self) -> bool
Returns true if and only if this set contains any Unicode word boundary or negated Unicode word boundary assertions.
Sourcepub fn contains_word_ascii(self) -> bool
pub fn contains_word_ascii(self) -> bool
Returns true if and only if this set contains any ASCII word boundary or negated ASCII word boundary assertions.
Sourcepub fn iter(self) -> LookSetIter ⓘ
pub fn iter(self) -> LookSetIter ⓘ
Returns an iterator over all of the look-around assertions in this set.
Sourcepub fn insert(self, look: Look) -> LookSet
pub fn insert(self, look: Look) -> LookSet
Return a new set that is equivalent to the original, but with the given assertion added to it. If the assertion is already in the set, then the returned set is equivalent to the original.
Sourcepub fn set_insert(&mut self, look: Look)
pub fn set_insert(&mut self, look: Look)
Updates this set in place with the result of inserting the given assertion into this set.
Sourcepub fn remove(self, look: Look) -> LookSet
pub fn remove(self, look: Look) -> LookSet
Return a new set that is equivalent to the original, but with the given assertion removed from it. If the assertion is not in the set, then the returned set is equivalent to the original.
Sourcepub fn set_remove(&mut self, look: Look)
pub fn set_remove(&mut self, look: Look)
Updates this set in place with the result of removing the given assertion from this set.
Sourcepub fn subtract(self, other: LookSet) -> LookSet
pub fn subtract(self, other: LookSet) -> LookSet
Returns a new set that is the result of subtracting the given set from this set.
Sourcepub fn set_subtract(&mut self, other: LookSet)
pub fn set_subtract(&mut self, other: LookSet)
Updates this set in place with the result of subtracting the given set from this set.
Sourcepub fn union(self, other: LookSet) -> LookSet
pub fn union(self, other: LookSet) -> LookSet
Returns a new set that is the union of this and the one given.
Sourcepub fn set_union(&mut self, other: LookSet)
pub fn set_union(&mut self, other: LookSet)
Updates this set in place with the result of unioning it with the one given.
Sourcepub fn intersect(self, other: LookSet) -> LookSet
pub fn intersect(self, other: LookSet) -> LookSet
Returns a new set that is the intersection of this and the one given.
Sourcepub fn set_intersect(&mut self, other: LookSet)
pub fn set_intersect(&mut self, other: LookSet)
Updates this set in place with the result of intersecting it with the one given.
Sourcepub fn read_repr(slice: &[u8]) -> LookSet
pub fn read_repr(slice: &[u8]) -> LookSet
Return a LookSet from the slice given as a native endian 32-bit
integer.
§Panics
This panics if slice.len() < 4.
Sourcepub fn write_repr(self, slice: &mut [u8])
pub fn write_repr(self, slice: &mut [u8])
Write a LookSet as a native endian 32-bit integer to the beginning
of the slice given.
§Panics
This panics if slice.len() < 4.
Sourcepub fn available(self) -> Result<(), UnicodeWordBoundaryError>
pub fn available(self) -> Result<(), UnicodeWordBoundaryError>
Checks that all assertions in this set can be matched.
Some assertions, such as Unicode word boundaries, require optional (but enabled by default) tables that may not be available. If there are assertions in this set that require tables that are not available, then this will return an error.
Specifically, this returns an error when the the
unicode-word-boundary feature is not enabled and this set
contains a Unicode word boundary assertion.
It can be useful to use this on the result of
NFA::look_set_any
when building a matcher engine to ensure methods like
LookMatcher::matches_set do not panic at search time.