Struct regex::prog::Program [−][src]
pub struct Program { pub insts: Vec<Inst>, pub matches: Vec<usize>, pub captures: Vec<Option<String>>, pub capture_name_idx: Arc<HashMap<String, usize>>, pub start: usize, pub byte_classes: Vec<u8>, pub only_utf8: bool, pub is_bytes: bool, pub is_dfa: bool, pub is_reverse: bool, pub is_anchored_start: bool, pub is_anchored_end: bool, pub has_unicode_word_boundary: bool, pub prefixes: LiteralSearcher, pub dfa_size_limit: usize, }
Program is a sequence of instructions and various facts about thos instructions.
Fields
insts: Vec<Inst>
A sequence of instructions that represents an NFA.
matches: Vec<usize>
Pointers to each Match instruction in the sequence.
This is always length 1 unless this program represents a regex set.
captures: Vec<Option<String>>
The ordered sequence of all capture groups extracted from the AST.
Unnamed groups are None
.
capture_name_idx: Arc<HashMap<String, usize>>
Pointers to all named capture groups into captures
.
start: usize
A pointer to the start instruction. This can vary depending on how
the program was compiled. For example, programs for use with the DFA
engine have a .*?
inserted at the beginning of unanchored regular
expressions. The actual starting point of the program is after the
.*?
.
byte_classes: Vec<u8>
A set of equivalence classes for discriminating bytes in the compiled program.
only_utf8: bool
When true, this program can only match valid UTF-8.
is_bytes: bool
When true, this program uses byte range instructions instead of Unicode range instructions.
is_dfa: bool
When true, the program is compiled for DFA matching. For example, this
implies is_bytes
and also inserts a preceding .*?
for unanchored
regexes.
is_reverse: bool
When true, the program matches text in reverse (for use only in the DFA).
is_anchored_start: bool
Whether the regex must match from the start of the input.
is_anchored_end: bool
Whether the regex must match at the end of the input.
has_unicode_word_boundary: bool
Whether this program contains a Unicode word boundary instruction.
prefixes: LiteralSearcher
A possibly empty machine for very quickly matching prefix literals.
dfa_size_limit: usize
A limit on the size of the cache that the DFA is allowed to use while matching.
The cache limit specifies approximately how much space we're willing to give to the state cache. Once the state cache exceeds the size, it is wiped and all states must be re-computed.
Note that this value does not impact correctness. It can be set to 0 and the DFA will run just fine. (It will only ever store exactly one state in the cache, and will likely run very slowly, but it will work.)
Also note that this limit is per thread of execution. That is, if the same regex is used to search text across multiple threads simultaneously, then the DFA cache is not shared. Instead, copies are made.
Methods
impl Program
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impl Program
pub fn new() -> Self
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pub fn new() -> Self
Creates an empty instruction sequence. Fields are given default values.
pub fn skip(&self, pc: usize) -> usize
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pub fn skip(&self, pc: usize) -> usize
If pc is an index to a no-op instruction (like Save), then return the next pc that is not a no-op instruction.
pub fn leads_to_match(&self, pc: usize) -> bool
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pub fn leads_to_match(&self, pc: usize) -> bool
Return true if and only if an execution engine at instruction pc
will
always lead to a match.
pub fn needs_dotstar(&self) -> bool
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pub fn needs_dotstar(&self) -> bool
Returns true if the current configuration demands that an implicit
.*?
be prepended to the instruction sequence.
pub fn uses_bytes(&self) -> bool
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pub fn uses_bytes(&self) -> bool
Returns true if this program uses Byte instructions instead of Char/Range instructions.
pub fn only_utf8(&self) -> bool
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pub fn only_utf8(&self) -> bool
Returns true if this program exclusively matches valid UTF-8 bytes.
That is, if an invalid UTF-8 byte is seen, then no match is possible.
pub fn approximate_size(&self) -> usize
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pub fn approximate_size(&self) -> usize
Return the approximate heap usage of this instruction sequence in bytes.
Methods from Deref<Target = [Inst]>
pub const fn len(&self) -> usize
1.0.0[src]
pub const fn len(&self) -> usize
pub const fn is_empty(&self) -> bool
1.0.0[src]
pub const fn is_empty(&self) -> bool
pub fn first(&self) -> Option<&T>
1.0.0[src]
pub fn first(&self) -> Option<&T>
Returns the first element of the slice, or None
if it is empty.
Examples
let v = [10, 40, 30]; assert_eq!(Some(&10), v.first()); let w: &[i32] = &[]; assert_eq!(None, w.first());
pub fn split_first(&self) -> Option<(&T, &[T])>
1.5.0[src]
pub fn split_first(&self) -> Option<(&T, &[T])>
Returns the first and all the rest of the elements of the slice, or None
if it is empty.
Examples
let x = &[0, 1, 2]; if let Some((first, elements)) = x.split_first() { assert_eq!(first, &0); assert_eq!(elements, &[1, 2]); }
pub fn split_last(&self) -> Option<(&T, &[T])>
1.5.0[src]
pub fn split_last(&self) -> Option<(&T, &[T])>
Returns the last and all the rest of the elements of the slice, or None
if it is empty.
Examples
let x = &[0, 1, 2]; if let Some((last, elements)) = x.split_last() { assert_eq!(last, &2); assert_eq!(elements, &[0, 1]); }
pub fn last(&self) -> Option<&T>
1.0.0[src]
pub fn last(&self) -> Option<&T>
Returns the last element of the slice, or None
if it is empty.
Examples
let v = [10, 40, 30]; assert_eq!(Some(&30), v.last()); let w: &[i32] = &[]; assert_eq!(None, w.last());
pub fn get<I>(&self, index: I) -> Option<&<I as SliceIndex<[T]>>::Output> where
I: SliceIndex<[T]>,
1.0.0[src]
pub fn get<I>(&self, index: I) -> Option<&<I as SliceIndex<[T]>>::Output> where
I: SliceIndex<[T]>,
Returns a reference to an element or subslice depending on the type of index.
- If given a position, returns a reference to the element at that
position or
None
if out of bounds. - If given a range, returns the subslice corresponding to that range,
or
None
if out of bounds.
Examples
let v = [10, 40, 30]; assert_eq!(Some(&40), v.get(1)); assert_eq!(Some(&[10, 40][..]), v.get(0..2)); assert_eq!(None, v.get(3)); assert_eq!(None, v.get(0..4));
pub unsafe fn get_unchecked<I>(
&self,
index: I
) -> &<I as SliceIndex<[T]>>::Output where
I: SliceIndex<[T]>,
1.0.0[src]
pub unsafe fn get_unchecked<I>(
&self,
index: I
) -> &<I as SliceIndex<[T]>>::Output where
I: SliceIndex<[T]>,
Returns a reference to an element or subslice, without doing bounds checking.
This is generally not recommended, use with caution! For a safe
alternative see get
.
Examples
let x = &[1, 2, 4]; unsafe { assert_eq!(x.get_unchecked(1), &2); }
pub const fn as_ptr(&self) -> *const T
1.0.0[src]
pub const fn as_ptr(&self) -> *const T
Returns a raw pointer to the slice's buffer.
The caller must ensure that the slice outlives the pointer this function returns, or else it will end up pointing to garbage.
Modifying the container referenced by this slice may cause its buffer to be reallocated, which would also make any pointers to it invalid.
Examples
let x = &[1, 2, 4]; let x_ptr = x.as_ptr(); unsafe { for i in 0..x.len() { assert_eq!(x.get_unchecked(i), &*x_ptr.offset(i as isize)); } }
pub fn iter(&self) -> Iter<T>
1.0.0[src]
pub fn iter(&self) -> Iter<T>
Returns an iterator over the slice.
Examples
let x = &[1, 2, 4]; let mut iterator = x.iter(); assert_eq!(iterator.next(), Some(&1)); assert_eq!(iterator.next(), Some(&2)); assert_eq!(iterator.next(), Some(&4)); assert_eq!(iterator.next(), None);
pub fn windows(&self, size: usize) -> Windows<T>
1.0.0[src]
pub fn windows(&self, size: usize) -> Windows<T>
Returns an iterator over all contiguous windows of length
size
. The windows overlap. If the slice is shorter than
size
, the iterator returns no values.
Panics
Panics if size
is 0.
Examples
let slice = ['r', 'u', 's', 't']; let mut iter = slice.windows(2); assert_eq!(iter.next().unwrap(), &['r', 'u']); assert_eq!(iter.next().unwrap(), &['u', 's']); assert_eq!(iter.next().unwrap(), &['s', 't']); assert!(iter.next().is_none());
If the slice is shorter than size
:
let slice = ['f', 'o', 'o']; let mut iter = slice.windows(4); assert!(iter.next().is_none());
pub fn chunks(&self, chunk_size: usize) -> Chunks<T>
1.0.0[src]
pub fn chunks(&self, chunk_size: usize) -> Chunks<T>
Returns an iterator over chunk_size
elements of the slice at a
time. The chunks are slices and do not overlap. If chunk_size
does
not divide the length of the slice, then the last chunk will
not have length chunk_size
.
See exact_chunks
for a variant of this iterator that returns chunks
of always exactly chunk_size
elements.
Panics
Panics if chunk_size
is 0.
Examples
let slice = ['l', 'o', 'r', 'e', 'm']; let mut iter = slice.chunks(2); assert_eq!(iter.next().unwrap(), &['l', 'o']); assert_eq!(iter.next().unwrap(), &['r', 'e']); assert_eq!(iter.next().unwrap(), &['m']); assert!(iter.next().is_none());
pub fn exact_chunks(&self, chunk_size: usize) -> ExactChunks<T>
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pub fn exact_chunks(&self, chunk_size: usize) -> ExactChunks<T>
exact_chunks
)Returns an iterator over chunk_size
elements of the slice at a
time. The chunks are slices and do not overlap. If chunk_size
does
not divide the length of the slice, then the last up to chunk_size-1
elements will be omitted and can be retrieved from the remainder
function of the iterator.
Due to each chunk having exactly chunk_size
elements, the compiler
can often optimize the resulting code better than in the case of
chunks
.
Panics
Panics if chunk_size
is 0.
Examples
#![feature(exact_chunks)] let slice = ['l', 'o', 'r', 'e', 'm']; let mut iter = slice.exact_chunks(2); assert_eq!(iter.next().unwrap(), &['l', 'o']); assert_eq!(iter.next().unwrap(), &['r', 'e']); assert!(iter.next().is_none());
pub fn split_at(&self, mid: usize) -> (&[T], &[T])
1.0.0[src]
pub fn split_at(&self, mid: usize) -> (&[T], &[T])
Divides one slice into two at an index.
The first will contain all indices from [0, mid)
(excluding
the index mid
itself) and the second will contain all
indices from [mid, len)
(excluding the index len
itself).
Panics
Panics if mid > len
.
Examples
let v = [1, 2, 3, 4, 5, 6]; { let (left, right) = v.split_at(0); assert!(left == []); assert!(right == [1, 2, 3, 4, 5, 6]); } { let (left, right) = v.split_at(2); assert!(left == [1, 2]); assert!(right == [3, 4, 5, 6]); } { let (left, right) = v.split_at(6); assert!(left == [1, 2, 3, 4, 5, 6]); assert!(right == []); }
pub fn split<F>(&self, pred: F) -> Split<T, F> where
F: FnMut(&T) -> bool,
1.0.0[src]
pub fn split<F>(&self, pred: F) -> Split<T, F> where
F: FnMut(&T) -> bool,
Returns an iterator over subslices separated by elements that match
pred
. The matched element is not contained in the subslices.
Examples
let slice = [10, 40, 33, 20]; let mut iter = slice.split(|num| num % 3 == 0); assert_eq!(iter.next().unwrap(), &[10, 40]); assert_eq!(iter.next().unwrap(), &[20]); assert!(iter.next().is_none());
If the first element is matched, an empty slice will be the first item returned by the iterator. Similarly, if the last element in the slice is matched, an empty slice will be the last item returned by the iterator:
let slice = [10, 40, 33]; let mut iter = slice.split(|num| num % 3 == 0); assert_eq!(iter.next().unwrap(), &[10, 40]); assert_eq!(iter.next().unwrap(), &[]); assert!(iter.next().is_none());
If two matched elements are directly adjacent, an empty slice will be present between them:
let slice = [10, 6, 33, 20]; let mut iter = slice.split(|num| num % 3 == 0); assert_eq!(iter.next().unwrap(), &[10]); assert_eq!(iter.next().unwrap(), &[]); assert_eq!(iter.next().unwrap(), &[20]); assert!(iter.next().is_none());
pub fn rsplit<F>(&self, pred: F) -> RSplit<T, F> where
F: FnMut(&T) -> bool,
1.27.0[src]
pub fn rsplit<F>(&self, pred: F) -> RSplit<T, F> where
F: FnMut(&T) -> bool,
Returns an iterator over subslices separated by elements that match
pred
, starting at the end of the slice and working backwards.
The matched element is not contained in the subslices.
Examples
let slice = [11, 22, 33, 0, 44, 55]; let mut iter = slice.rsplit(|num| *num == 0); assert_eq!(iter.next().unwrap(), &[44, 55]); assert_eq!(iter.next().unwrap(), &[11, 22, 33]); assert_eq!(iter.next(), None);
As with split()
, if the first or last element is matched, an empty
slice will be the first (or last) item returned by the iterator.
let v = &[0, 1, 1, 2, 3, 5, 8]; let mut it = v.rsplit(|n| *n % 2 == 0); assert_eq!(it.next().unwrap(), &[]); assert_eq!(it.next().unwrap(), &[3, 5]); assert_eq!(it.next().unwrap(), &[1, 1]); assert_eq!(it.next().unwrap(), &[]); assert_eq!(it.next(), None);
pub fn splitn<F>(&self, n: usize, pred: F) -> SplitN<T, F> where
F: FnMut(&T) -> bool,
1.0.0[src]
pub fn splitn<F>(&self, n: usize, pred: F) -> SplitN<T, F> where
F: FnMut(&T) -> bool,
Returns an iterator over subslices separated by elements that match
pred
, limited to returning at most n
items. The matched element is
not contained in the subslices.
The last element returned, if any, will contain the remainder of the slice.
Examples
Print the slice split once by numbers divisible by 3 (i.e. [10, 40]
,
[20, 60, 50]
):
let v = [10, 40, 30, 20, 60, 50]; for group in v.splitn(2, |num| *num % 3 == 0) { println!("{:?}", group); }
pub fn rsplitn<F>(&self, n: usize, pred: F) -> RSplitN<T, F> where
F: FnMut(&T) -> bool,
1.0.0[src]
pub fn rsplitn<F>(&self, n: usize, pred: F) -> RSplitN<T, F> where
F: FnMut(&T) -> bool,
Returns an iterator over subslices separated by elements that match
pred
limited to returning at most n
items. This starts at the end of
the slice and works backwards. The matched element is not contained in
the subslices.
The last element returned, if any, will contain the remainder of the slice.
Examples
Print the slice split once, starting from the end, by numbers divisible
by 3 (i.e. [50]
, [10, 40, 30, 20]
):
let v = [10, 40, 30, 20, 60, 50]; for group in v.rsplitn(2, |num| *num % 3 == 0) { println!("{:?}", group); }
pub fn contains(&self, x: &T) -> bool where
T: PartialEq<T>,
1.0.0[src]
pub fn contains(&self, x: &T) -> bool where
T: PartialEq<T>,
Returns true
if the slice contains an element with the given value.
Examples
let v = [10, 40, 30]; assert!(v.contains(&30)); assert!(!v.contains(&50));
pub fn starts_with(&self, needle: &[T]) -> bool where
T: PartialEq<T>,
1.0.0[src]
pub fn starts_with(&self, needle: &[T]) -> bool where
T: PartialEq<T>,
Returns true
if needle
is a prefix of the slice.
Examples
let v = [10, 40, 30]; assert!(v.starts_with(&[10])); assert!(v.starts_with(&[10, 40])); assert!(!v.starts_with(&[50])); assert!(!v.starts_with(&[10, 50]));
Always returns true
if needle
is an empty slice:
let v = &[10, 40, 30]; assert!(v.starts_with(&[])); let v: &[u8] = &[]; assert!(v.starts_with(&[]));
pub fn ends_with(&self, needle: &[T]) -> bool where
T: PartialEq<T>,
1.0.0[src]
pub fn ends_with(&self, needle: &[T]) -> bool where
T: PartialEq<T>,
Returns true
if needle
is a suffix of the slice.
Examples
let v = [10, 40, 30]; assert!(v.ends_with(&[30])); assert!(v.ends_with(&[40, 30])); assert!(!v.ends_with(&[50])); assert!(!v.ends_with(&[50, 30]));
Always returns true
if needle
is an empty slice:
let v = &[10, 40, 30]; assert!(v.ends_with(&[])); let v: &[u8] = &[]; assert!(v.ends_with(&[]));
pub fn binary_search(&self, x: &T) -> Result<usize, usize> where
T: Ord,
1.0.0[src]
pub fn binary_search(&self, x: &T) -> Result<usize, usize> where
T: Ord,
Binary searches this sorted slice for a given element.
If the value is found then Ok
is returned, containing the
index of the matching element; if the value is not found then
Err
is returned, containing the index where a matching
element could be inserted while maintaining sorted order.
Examples
Looks up a series of four elements. The first is found, with a
uniquely determined position; the second and third are not
found; the fourth could match any position in [1, 4]
.
let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55]; assert_eq!(s.binary_search(&13), Ok(9)); assert_eq!(s.binary_search(&4), Err(7)); assert_eq!(s.binary_search(&100), Err(13)); let r = s.binary_search(&1); assert!(match r { Ok(1..=4) => true, _ => false, });
pub fn binary_search_by<'a, F>(&'a self, f: F) -> Result<usize, usize> where
F: FnMut(&'a T) -> Ordering,
1.0.0[src]
pub fn binary_search_by<'a, F>(&'a self, f: F) -> Result<usize, usize> where
F: FnMut(&'a T) -> Ordering,
Binary searches this sorted slice with a comparator function.
The comparator function should implement an order consistent
with the sort order of the underlying slice, returning an
order code that indicates whether its argument is Less
,
Equal
or Greater
the desired target.
If a matching value is found then returns Ok
, containing
the index for the matched element; if no match is found then
Err
is returned, containing the index where a matching
element could be inserted while maintaining sorted order.
Examples
Looks up a series of four elements. The first is found, with a
uniquely determined position; the second and third are not
found; the fourth could match any position in [1, 4]
.
let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55]; let seek = 13; assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Ok(9)); let seek = 4; assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(7)); let seek = 100; assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(13)); let seek = 1; let r = s.binary_search_by(|probe| probe.cmp(&seek)); assert!(match r { Ok(1..=4) => true, _ => false, });
pub fn binary_search_by_key<'a, B, F>(
&'a self,
b: &B,
f: F
) -> Result<usize, usize> where
B: Ord,
F: FnMut(&'a T) -> B,
1.10.0[src]
pub fn binary_search_by_key<'a, B, F>(
&'a self,
b: &B,
f: F
) -> Result<usize, usize> where
B: Ord,
F: FnMut(&'a T) -> B,
Binary searches this sorted slice with a key extraction function.
Assumes that the slice is sorted by the key, for instance with
sort_by_key
using the same key extraction function.
If a matching value is found then returns Ok
, containing the
index for the matched element; if no match is found then Err
is returned, containing the index where a matching element could
be inserted while maintaining sorted order.
Examples
Looks up a series of four elements in a slice of pairs sorted by
their second elements. The first is found, with a uniquely
determined position; the second and third are not found; the
fourth could match any position in [1, 4]
.
let s = [(0, 0), (2, 1), (4, 1), (5, 1), (3, 1), (1, 2), (2, 3), (4, 5), (5, 8), (3, 13), (1, 21), (2, 34), (4, 55)]; assert_eq!(s.binary_search_by_key(&13, |&(a,b)| b), Ok(9)); assert_eq!(s.binary_search_by_key(&4, |&(a,b)| b), Err(7)); assert_eq!(s.binary_search_by_key(&100, |&(a,b)| b), Err(13)); let r = s.binary_search_by_key(&1, |&(a,b)| b); assert!(match r { Ok(1..=4) => true, _ => false, });
pub unsafe fn align_to<U>(&self) -> (&[T], &[U], &[T])
[src]
pub unsafe fn align_to<U>(&self) -> (&[T], &[U], &[T])
slice_align_to
)Transmute the slice to a slice of another type, ensuring aligment of the types is maintained.
This method splits the slice into three distinct slices: prefix, correctly aligned middle slice of a new type, and the suffix slice. The middle slice will have the greatest length possible for a given type and input slice.
This method has no purpose when either input element T
or output element U
are
zero-sized and will return the original slice without splitting anything.
Unsafety
This method is essentially a transmute
with respect to the elements in the returned
middle slice, so all the usual caveats pertaining to transmute::<T, U>
also apply here.
Examples
Basic usage:
unsafe { let bytes: [u8; 7] = [1, 2, 3, 4, 5, 6, 7]; let (prefix, shorts, suffix) = bytes.align_to::<u16>(); // less_efficient_algorithm_for_bytes(prefix); // more_efficient_algorithm_for_aligned_shorts(shorts); // less_efficient_algorithm_for_bytes(suffix); }
Trait Implementations
impl Clone for Program
[src]
impl Clone for Program
fn clone(&self) -> Program
[src]
fn clone(&self) -> Program
Returns a copy of the value. Read more
fn clone_from(&mut self, source: &Self)
1.0.0[src]
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from source
. Read more
impl Deref for Program
[src]
impl Deref for Program
type Target = [Inst]
The resulting type after dereferencing.
fn deref(&self) -> &Self::Target
[src]
fn deref(&self) -> &Self::Target
Dereferences the value.
impl Debug for Program
[src]
impl Debug for Program
fn fmt(&self, f: &mut Formatter) -> Result
[src]
fn fmt(&self, f: &mut Formatter) -> Result
Formats the value using the given formatter. Read more
impl<'a> IntoIterator for &'a Program
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impl<'a> IntoIterator for &'a Program