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use std::borrow::Cow;
use std::collections::HashMap;
use std::fmt;
use std::ops::Index;
use std::str::FromStr;
use std::sync::Arc;
use find_byte::find_byte;
use syntax;
use error::Error;
use exec::{Exec, ExecNoSyncStr};
use expand::expand_str;
use re_builder::unicode::RegexBuilder;
use re_trait::{self, RegularExpression, SubCapturesPosIter};
/// Escapes all regular expression meta characters in `text`.
///
/// The string returned may be safely used as a literal in a regular
/// expression.
pub fn escape(text: &str) -> String {
syntax::escape(text)
}
/// Match represents a single match of a regex in a haystack.
///
/// The lifetime parameter `'t` refers to the lifetime of the matched text.
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
pub struct Match<'t> {
text: &'t str,
start: usize,
end: usize,
}
impl<'t> Match<'t> {
/// Returns the starting byte offset of the match in the haystack.
#[inline]
pub fn start(&self) -> usize {
self.start
}
/// Returns the ending byte offset of the match in the haystack.
#[inline]
pub fn end(&self) -> usize {
self.end
}
/// Returns the matched text.
#[inline]
pub fn as_str(&self) -> &'t str {
&self.text[self.start..self.end]
}
/// Creates a new match from the given haystack and byte offsets.
#[inline]
fn new(haystack: &'t str, start: usize, end: usize) -> Match<'t> {
Match { text: haystack, start: start, end: end }
}
}
impl<'t> From<Match<'t>> for &'t str {
fn from(m: Match<'t>) -> &'t str {
m.as_str()
}
}
/// A compiled regular expression for matching Unicode strings.
///
/// It is represented as either a sequence of bytecode instructions (dynamic)
/// or as a specialized Rust function (native). It can be used to search, split
/// or replace text. All searching is done with an implicit `.*?` at the
/// beginning and end of an expression. To force an expression to match the
/// whole string (or a prefix or a suffix), you must use an anchor like `^` or
/// `$` (or `\A` and `\z`).
///
/// While this crate will handle Unicode strings (whether in the regular
/// expression or in the search text), all positions returned are **byte
/// indices**. Every byte index is guaranteed to be at a Unicode code point
/// boundary.
///
/// The lifetimes `'r` and `'t` in this crate correspond to the lifetime of a
/// compiled regular expression and text to search, respectively.
///
/// The only methods that allocate new strings are the string replacement
/// methods. All other methods (searching and splitting) return borrowed
/// pointers into the string given.
///
/// # Examples
///
/// Find the location of a US phone number:
///
/// ```rust
/// # use regex::Regex;
/// let re = Regex::new("[0-9]{3}-[0-9]{3}-[0-9]{4}").unwrap();
/// let mat = re.find("phone: 111-222-3333").unwrap();
/// assert_eq!((mat.start(), mat.end()), (7, 19));
/// ```
///
/// # Using the `std::str::pattern` methods with `Regex`
///
/// > **Note**: This section requires that this crate is compiled with the
/// > `pattern` Cargo feature enabled, which **requires nightly Rust**.
///
/// Since `Regex` implements `Pattern`, you can use regexes with methods
/// defined on `&str`. For example, `is_match`, `find`, `find_iter`
/// and `split` can be replaced with `str::contains`, `str::find`,
/// `str::match_indices` and `str::split`.
///
/// Here are some examples:
///
/// ```rust,ignore
/// # use regex::Regex;
/// let re = Regex::new(r"\d+").unwrap();
/// let haystack = "a111b222c";
///
/// assert!(haystack.contains(&re));
/// assert_eq!(haystack.find(&re), Some(1));
/// assert_eq!(haystack.match_indices(&re).collect::<Vec<_>>(),
/// vec![(1, 4), (5, 8)]);
/// assert_eq!(haystack.split(&re).collect::<Vec<_>>(), vec!["a", "b", "c"]);
/// ```
#[derive(Clone)]
pub struct Regex(Exec);
impl fmt::Display for Regex {
/// Shows the original regular expression.
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}", self.as_str())
}
}
impl fmt::Debug for Regex {
/// Shows the original regular expression.
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Display::fmt(self, f)
}
}
#[doc(hidden)]
impl From<Exec> for Regex {
fn from(exec: Exec) -> Regex {
Regex(exec)
}
}
impl FromStr for Regex {
type Err = Error;
/// Attempts to parse a string into a regular expression
fn from_str(s: &str) -> Result<Regex, Error> {
Regex::new(s)
}
}
/// Core regular expression methods.
impl Regex {
/// Compiles a regular expression. Once compiled, it can be used repeatedly
/// to search, split or replace text in a string.
///
/// If an invalid expression is given, then an error is returned.
pub fn new(re: &str) -> Result<Regex, Error> {
RegexBuilder::new(re).build()
}
/// Returns true if and only if the regex matches the string given.
///
/// It is recommended to use this method if all you need to do is test
/// a match, since the underlying matching engine may be able to do less
/// work.
///
/// # Example
///
/// Test if some text contains at least one word with exactly 13
/// Unicode word characters:
///
/// ```rust
/// # extern crate regex; use regex::Regex;
/// # fn main() {
/// let text = "I categorically deny having triskaidekaphobia.";
/// assert!(Regex::new(r"\b\w{13}\b").unwrap().is_match(text));
/// # }
/// ```
pub fn is_match(&self, text: &str) -> bool {
self.is_match_at(text, 0)
}
/// Returns the start and end byte range of the leftmost-first match in
/// `text`. If no match exists, then `None` is returned.
///
/// Note that this should only be used if you want to discover the position
/// of the match. Testing the existence of a match is faster if you use
/// `is_match`.
///
/// # Example
///
/// Find the start and end location of the first word with exactly 13
/// Unicode word characters:
///
/// ```rust
/// # extern crate regex; use regex::Regex;
/// # fn main() {
/// let text = "I categorically deny having triskaidekaphobia.";
/// let mat = Regex::new(r"\b\w{13}\b").unwrap().find(text).unwrap();
/// assert_eq!(mat.start(), 2);
/// assert_eq!(mat.end(), 15);
/// # }
/// ```
pub fn find<'t>(&self, text: &'t str) -> Option<Match<'t>> {
self.find_at(text, 0)
}
/// Returns an iterator for each successive non-overlapping match in
/// `text`, returning the start and end byte indices with respect to
/// `text`.
///
/// # Example
///
/// Find the start and end location of every word with exactly 13 Unicode
/// word characters:
///
/// ```rust
/// # extern crate regex; use regex::Regex;
/// # fn main() {
/// let text = "Retroactively relinquishing remunerations is reprehensible.";
/// for mat in Regex::new(r"\b\w{13}\b").unwrap().find_iter(text) {
/// println!("{:?}", mat);
/// }
/// # }
/// ```
pub fn find_iter<'r, 't>(&'r self, text: &'t str) -> Matches<'r, 't> {
Matches(self.0.searcher_str().find_iter(text))
}
/// Returns the capture groups corresponding to the leftmost-first
/// match in `text`. Capture group `0` always corresponds to the entire
/// match. If no match is found, then `None` is returned.
///
/// You should only use `captures` if you need access to the location of
/// capturing group matches. Otherwise, `find` is faster for discovering
/// the location of the overall match.
///
/// # Examples
///
/// Say you have some text with movie names and their release years,
/// like "'Citizen Kane' (1941)". It'd be nice if we could search for text
/// looking like that, while also extracting the movie name and its release
/// year separately.
///
/// ```rust
/// # extern crate regex; use regex::Regex;
/// # fn main() {
/// let re = Regex::new(r"'([^']+)'\s+\((\d{4})\)").unwrap();
/// let text = "Not my favorite movie: 'Citizen Kane' (1941).";
/// let caps = re.captures(text).unwrap();
/// assert_eq!(caps.get(1).unwrap().as_str(), "Citizen Kane");
/// assert_eq!(caps.get(2).unwrap().as_str(), "1941");
/// assert_eq!(caps.get(0).unwrap().as_str(), "'Citizen Kane' (1941)");
/// // You can also access the groups by index using the Index notation.
/// // Note that this will panic on an invalid index.
/// assert_eq!(&caps[1], "Citizen Kane");
/// assert_eq!(&caps[2], "1941");
/// assert_eq!(&caps[0], "'Citizen Kane' (1941)");
/// # }
/// ```
///
/// Note that the full match is at capture group `0`. Each subsequent
/// capture group is indexed by the order of its opening `(`.
///
/// We can make this example a bit clearer by using *named* capture groups:
///
/// ```rust
/// # extern crate regex; use regex::Regex;
/// # fn main() {
/// let re = Regex::new(r"'(?P<title>[^']+)'\s+\((?P<year>\d{4})\)")
/// .unwrap();
/// let text = "Not my favorite movie: 'Citizen Kane' (1941).";
/// let caps = re.captures(text).unwrap();
/// assert_eq!(caps.name("title").unwrap().as_str(), "Citizen Kane");
/// assert_eq!(caps.name("year").unwrap().as_str(), "1941");
/// assert_eq!(caps.get(0).unwrap().as_str(), "'Citizen Kane' (1941)");
/// // You can also access the groups by name using the Index notation.
/// // Note that this will panic on an invalid group name.
/// assert_eq!(&caps["title"], "Citizen Kane");
/// assert_eq!(&caps["year"], "1941");
/// assert_eq!(&caps[0], "'Citizen Kane' (1941)");
///
/// # }
/// ```
///
/// Here we name the capture groups, which we can access with the `name`
/// method or the `Index` notation with a `&str`. Note that the named
/// capture groups are still accessible with `get` or the `Index` notation
/// with a `usize`.
///
/// The `0`th capture group is always unnamed, so it must always be
/// accessed with `get(0)` or `[0]`.
pub fn captures<'t>(&self, text: &'t str) -> Option<Captures<'t>> {
let mut locs = self.capture_locations();
self.captures_read_at(&mut locs, text, 0).map(move |_| Captures {
text: text,
locs: locs.0,
named_groups: self.0.capture_name_idx().clone(),
})
}
/// Returns an iterator over all the non-overlapping capture groups matched
/// in `text`. This is operationally the same as `find_iter`, except it
/// yields information about capturing group matches.
///
/// # Example
///
/// We can use this to find all movie titles and their release years in
/// some text, where the movie is formatted like "'Title' (xxxx)":
///
/// ```rust
/// # extern crate regex; use regex::Regex;
/// # fn main() {
/// let re = Regex::new(r"'(?P<title>[^']+)'\s+\((?P<year>\d{4})\)")
/// .unwrap();
/// let text = "'Citizen Kane' (1941), 'The Wizard of Oz' (1939), 'M' (1931).";
/// for caps in re.captures_iter(text) {
/// println!("Movie: {:?}, Released: {:?}",
/// &caps["title"], &caps["year"]);
/// }
/// // Output:
/// // Movie: Citizen Kane, Released: 1941
/// // Movie: The Wizard of Oz, Released: 1939
/// // Movie: M, Released: 1931
/// # }
/// ```
pub fn captures_iter<'r, 't>(
&'r self,
text: &'t str,
) -> CaptureMatches<'r, 't> {
CaptureMatches(self.0.searcher_str().captures_iter(text))
}
/// Returns an iterator of substrings of `text` delimited by a match of the
/// regular expression. Namely, each element of the iterator corresponds to
/// text that *isn't* matched by the regular expression.
///
/// This method will *not* copy the text given.
///
/// # Example
///
/// To split a string delimited by arbitrary amounts of spaces or tabs:
///
/// ```rust
/// # extern crate regex; use regex::Regex;
/// # fn main() {
/// let re = Regex::new(r"[ \t]+").unwrap();
/// let fields: Vec<&str> = re.split("a b \t c\td e").collect();
/// assert_eq!(fields, vec!["a", "b", "c", "d", "e"]);
/// # }
/// ```
pub fn split<'r, 't>(&'r self, text: &'t str) -> Split<'r, 't> {
Split { finder: self.find_iter(text), last: 0 }
}
/// Returns an iterator of at most `limit` substrings of `text` delimited
/// by a match of the regular expression. (A `limit` of `0` will return no
/// substrings.) Namely, each element of the iterator corresponds to text
/// that *isn't* matched by the regular expression. The remainder of the
/// string that is not split will be the last element in the iterator.
///
/// This method will *not* copy the text given.
///
/// # Example
///
/// Get the first two words in some text:
///
/// ```rust
/// # extern crate regex; use regex::Regex;
/// # fn main() {
/// let re = Regex::new(r"\W+").unwrap();
/// let fields: Vec<&str> = re.splitn("Hey! How are you?", 3).collect();
/// assert_eq!(fields, vec!("Hey", "How", "are you?"));
/// # }
/// ```
pub fn splitn<'r, 't>(
&'r self,
text: &'t str,
limit: usize,
) -> SplitN<'r, 't> {
SplitN { splits: self.split(text), n: limit }
}
/// Replaces the leftmost-first match with the replacement provided.
/// The replacement can be a regular string (where `$N` and `$name` are
/// expanded to match capture groups) or a function that takes the matches'
/// `Captures` and returns the replaced string.
///
/// If no match is found, then a copy of the string is returned unchanged.
///
/// # Replacement string syntax
///
/// All instances of `$name` in the replacement text is replaced with the
/// corresponding capture group `name`.
///
/// `name` may be an integer corresponding to the index of the
/// capture group (counted by order of opening parenthesis where `0` is the
/// entire match) or it can be a name (consisting of letters, digits or
/// underscores) corresponding to a named capture group.
///
/// If `name` isn't a valid capture group (whether the name doesn't exist
/// or isn't a valid index), then it is replaced with the empty string.
///
/// The longest possible name is used. e.g., `$1a` looks up the capture
/// group named `1a` and not the capture group at index `1`. To exert more
/// precise control over the name, use braces, e.g., `${1}a`.
///
/// To write a literal `$` use `$$`.
///
/// # Examples
///
/// Note that this function is polymorphic with respect to the replacement.
/// In typical usage, this can just be a normal string:
///
/// ```rust
/// # extern crate regex; use regex::Regex;
/// # fn main() {
/// let re = Regex::new("[^01]+").unwrap();
/// assert_eq!(re.replace("1078910", ""), "1010");
/// # }
/// ```
///
/// But anything satisfying the `Replacer` trait will work. For example,
/// a closure of type `|&Captures| -> String` provides direct access to the
/// captures corresponding to a match. This allows one to access
/// capturing group matches easily:
///
/// ```rust
/// # extern crate regex; use regex::Regex;
/// # use regex::Captures; fn main() {
/// let re = Regex::new(r"([^,\s]+),\s+(\S+)").unwrap();
/// let result = re.replace("Springsteen, Bruce", |caps: &Captures| {
/// format!("{} {}", &caps[2], &caps[1])
/// });
/// assert_eq!(result, "Bruce Springsteen");
/// # }
/// ```
///
/// But this is a bit cumbersome to use all the time. Instead, a simple
/// syntax is supported that expands `$name` into the corresponding capture
/// group. Here's the last example, but using this expansion technique
/// with named capture groups:
///
/// ```rust
/// # extern crate regex; use regex::Regex;
/// # fn main() {
/// let re = Regex::new(r"(?P<last>[^,\s]+),\s+(?P<first>\S+)").unwrap();
/// let result = re.replace("Springsteen, Bruce", "$first $last");
/// assert_eq!(result, "Bruce Springsteen");
/// # }
/// ```
///
/// Note that using `$2` instead of `$first` or `$1` instead of `$last`
/// would produce the same result. To write a literal `$` use `$$`.
///
/// Sometimes the replacement string requires use of curly braces to
/// delineate a capture group replacement and surrounding literal text.
/// For example, if we wanted to join two words together with an
/// underscore:
///
/// ```rust
/// # extern crate regex; use regex::Regex;
/// # fn main() {
/// let re = Regex::new(r"(?P<first>\w+)\s+(?P<second>\w+)").unwrap();
/// let result = re.replace("deep fried", "${first}_$second");
/// assert_eq!(result, "deep_fried");
/// # }
/// ```
///
/// Without the curly braces, the capture group name `first_` would be
/// used, and since it doesn't exist, it would be replaced with the empty
/// string.
///
/// Finally, sometimes you just want to replace a literal string with no
/// regard for capturing group expansion. This can be done by wrapping a
/// byte string with `NoExpand`:
///
/// ```rust
/// # extern crate regex; use regex::Regex;
/// # fn main() {
/// use regex::NoExpand;
///
/// let re = Regex::new(r"(?P<last>[^,\s]+),\s+(\S+)").unwrap();
/// let result = re.replace("Springsteen, Bruce", NoExpand("$2 $last"));
/// assert_eq!(result, "$2 $last");
/// # }
/// ```
pub fn replace<'t, R: Replacer>(
&self,
text: &'t str,
rep: R,
) -> Cow<'t, str> {
self.replacen(text, 1, rep)
}
/// Replaces all non-overlapping matches in `text` with the replacement
/// provided. This is the same as calling `replacen` with `limit` set to
/// `0`.
///
/// See the documentation for `replace` for details on how to access
/// capturing group matches in the replacement string.
pub fn replace_all<'t, R: Replacer>(
&self,
text: &'t str,
rep: R,
) -> Cow<'t, str> {
self.replacen(text, 0, rep)
}
/// Replaces at most `limit` non-overlapping matches in `text` with the
/// replacement provided. If `limit` is 0, then all non-overlapping matches
/// are replaced.
///
/// See the documentation for `replace` for details on how to access
/// capturing group matches in the replacement string.
pub fn replacen<'t, R: Replacer>(
&self,
text: &'t str,
limit: usize,
mut rep: R,
) -> Cow<'t, str> {
// If we know that the replacement doesn't have any capture expansions,
// then we can fast path. The fast path can make a tremendous
// difference:
//
// 1) We use `find_iter` instead of `captures_iter`. Not asking for
// captures generally makes the regex engines faster.
// 2) We don't need to look up all of the capture groups and do
// replacements inside the replacement string. We just push it
// at each match and be done with it.
if let Some(rep) = rep.no_expansion() {
let mut it = self.find_iter(text).enumerate().peekable();
if it.peek().is_none() {
return Cow::Borrowed(text);
}
let mut new = String::with_capacity(text.len());
let mut last_match = 0;
for (i, m) in it {
if limit > 0 && i >= limit {
break;
}
new.push_str(&text[last_match..m.start()]);
new.push_str(&rep);
last_match = m.end();
}
new.push_str(&text[last_match..]);
return Cow::Owned(new);
}
// The slower path, which we use if the replacement needs access to
// capture groups.
let mut it = self.captures_iter(text).enumerate().peekable();
if it.peek().is_none() {
return Cow::Borrowed(text);
}
let mut new = String::with_capacity(text.len());
let mut last_match = 0;
for (i, cap) in it {
if limit > 0 && i >= limit {
break;
}
// unwrap on 0 is OK because captures only reports matches
let m = cap.get(0).unwrap();
new.push_str(&text[last_match..m.start()]);
rep.replace_append(&cap, &mut new);
last_match = m.end();
}
new.push_str(&text[last_match..]);
Cow::Owned(new)
}
}
/// Advanced or "lower level" search methods.
impl Regex {
/// Returns the end location of a match in the text given.
///
/// This method may have the same performance characteristics as
/// `is_match`, except it provides an end location for a match. In
/// particular, the location returned *may be shorter* than the proper end
/// of the leftmost-first match.
///
/// # Example
///
/// Typically, `a+` would match the entire first sequence of `a` in some
/// text, but `shortest_match` can give up as soon as it sees the first
/// `a`.
///
/// ```rust
/// # extern crate regex; use regex::Regex;
/// # fn main() {
/// let text = "aaaaa";
/// let pos = Regex::new(r"a+").unwrap().shortest_match(text);
/// assert_eq!(pos, Some(1));
/// # }
/// ```
pub fn shortest_match(&self, text: &str) -> Option<usize> {
self.shortest_match_at(text, 0)
}
/// Returns the same as shortest_match, but starts the search at the given
/// offset.
///
/// The significance of the starting point is that it takes the surrounding
/// context into consideration. For example, the `\A` anchor can only
/// match when `start == 0`.
pub fn shortest_match_at(
&self,
text: &str,
start: usize,
) -> Option<usize> {
self.0.searcher_str().shortest_match_at(text, start)
}
/// Returns the same as is_match, but starts the search at the given
/// offset.
///
/// The significance of the starting point is that it takes the surrounding
/// context into consideration. For example, the `\A` anchor can only
/// match when `start == 0`.
pub fn is_match_at(&self, text: &str, start: usize) -> bool {
self.shortest_match_at(text, start).is_some()
}
/// Returns the same as find, but starts the search at the given
/// offset.
///
/// The significance of the starting point is that it takes the surrounding
/// context into consideration. For example, the `\A` anchor can only
/// match when `start == 0`.
pub fn find_at<'t>(
&self,
text: &'t str,
start: usize,
) -> Option<Match<'t>> {
self.0
.searcher_str()
.find_at(text, start)
.map(|(s, e)| Match::new(text, s, e))
}
/// This is like `captures`, but uses
/// [`CaptureLocations`](struct.CaptureLocations.html)
/// instead of
/// [`Captures`](struct.Captures.html) in order to amortize allocations.
///
/// To create a `CaptureLocations` value, use the
/// `Regex::capture_locations` method.
///
/// This returns the overall match if this was successful, which is always
/// equivalence to the `0`th capture group.
pub fn captures_read<'t>(
&self,
locs: &mut CaptureLocations,
text: &'t str,
) -> Option<Match<'t>> {
self.captures_read_at(locs, text, 0)
}
/// Returns the same as captures, but starts the search at the given
/// offset and populates the capture locations given.
///
/// The significance of the starting point is that it takes the surrounding
/// context into consideration. For example, the `\A` anchor can only
/// match when `start == 0`.
pub fn captures_read_at<'t>(
&self,
locs: &mut CaptureLocations,
text: &'t str,
start: usize,
) -> Option<Match<'t>> {
self.0
.searcher_str()
.captures_read_at(&mut locs.0, text, start)
.map(|(s, e)| Match::new(text, s, e))
}
/// An undocumented alias for `captures_read_at`.
///
/// The `regex-capi` crate previously used this routine, so to avoid
/// breaking that crate, we continue to provide the name as an undocumented
/// alias.
#[doc(hidden)]
pub fn read_captures_at<'t>(
&self,
locs: &mut CaptureLocations,
text: &'t str,
start: usize,
) -> Option<Match<'t>> {
self.captures_read_at(locs, text, start)
}
}
/// Auxiliary methods.
impl Regex {
/// Returns the original string of this regex.
pub fn as_str(&self) -> &str {
&self.0.regex_strings()[0]
}
/// Returns an iterator over the capture names.
pub fn capture_names(&self) -> CaptureNames {
CaptureNames(self.0.capture_names().iter())
}
/// Returns the number of captures.
pub fn captures_len(&self) -> usize {
self.0.capture_names().len()
}
/// Returns an empty set of capture locations that can be reused in
/// multiple calls to `captures_read` or `captures_read_at`.
pub fn capture_locations(&self) -> CaptureLocations {
CaptureLocations(self.0.searcher_str().locations())
}
/// An alias for `capture_locations` to preserve backward compatibility.
///
/// The `regex-capi` crate uses this method, so to avoid breaking that
/// crate, we continue to export it as an undocumented API.
#[doc(hidden)]
pub fn locations(&self) -> CaptureLocations {
CaptureLocations(self.0.searcher_str().locations())
}
}
/// An iterator over the names of all possible captures.
///
/// `None` indicates an unnamed capture; the first element (capture 0, the
/// whole matched region) is always unnamed.
///
/// `'r` is the lifetime of the compiled regular expression.
pub struct CaptureNames<'r>(::std::slice::Iter<'r, Option<String>>);
impl<'r> Iterator for CaptureNames<'r> {
type Item = Option<&'r str>;
fn next(&mut self) -> Option<Option<&'r str>> {
self.0
.next()
.as_ref()
.map(|slot| slot.as_ref().map(|name| name.as_ref()))
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.0.size_hint()
}
}
/// Yields all substrings delimited by a regular expression match.
///
/// `'r` is the lifetime of the compiled regular expression and `'t` is the
/// lifetime of the string being split.
pub struct Split<'r, 't> {
finder: Matches<'r, 't>,
last: usize,
}
impl<'r, 't> Iterator for Split<'r, 't> {
type Item = &'t str;
fn next(&mut self) -> Option<&'t str> {
let text = self.finder.0.text();
match self.finder.next() {
None => {
if self.last >= text.len() {
None
} else {
let s = &text[self.last..];
self.last = text.len();
Some(s)
}
}
Some(m) => {
let matched = &text[self.last..m.start()];
self.last = m.end();
Some(matched)
}
}
}
}
/// Yields at most `N` substrings delimited by a regular expression match.
///
/// The last substring will be whatever remains after splitting.
///
/// `'r` is the lifetime of the compiled regular expression and `'t` is the
/// lifetime of the string being split.
pub struct SplitN<'r, 't> {
splits: Split<'r, 't>,
n: usize,
}
impl<'r, 't> Iterator for SplitN<'r, 't> {
type Item = &'t str;
fn next(&mut self) -> Option<&'t str> {
if self.n == 0 {
return None;
}
self.n -= 1;
if self.n == 0 {
let text = self.splits.finder.0.text();
Some(&text[self.splits.last..])
} else {
self.splits.next()
}
}
}
/// CaptureLocations is a low level representation of the raw offsets of each
/// submatch.
///
/// You can think of this as a lower level
/// [`Captures`](struct.Captures.html), where this type does not support
/// named capturing groups directly and it does not borrow the text that these
/// offsets were matched on.
///
/// Primarily, this type is useful when using the lower level `Regex` APIs
/// such as `read_captures`, which permits amortizing the allocation in which
/// capture match locations are stored.
///
/// In order to build a value of this type, you'll need to call the
/// `capture_locations` method on the `Regex` being used to execute the search.
/// The value returned can then be reused in subsequent searches.
#[derive(Clone, Debug)]
pub struct CaptureLocations(re_trait::Locations);
/// A type alias for `CaptureLocations` for backwards compatibility.
///
/// Previously, we exported `CaptureLocations` as `Locations` in an
/// undocumented API. To prevent breaking that code (e.g., in `regex-capi`),
/// we continue re-exporting the same undocumented API.
#[doc(hidden)]
pub type Locations = CaptureLocations;
impl CaptureLocations {
/// Returns the start and end positions of the Nth capture group. Returns
/// `None` if `i` is not a valid capture group or if the capture group did
/// not match anything. The positions returned are *always* byte indices
/// with respect to the original string matched.
#[inline]
pub fn get(&self, i: usize) -> Option<(usize, usize)> {
self.0.pos(i)
}
/// Returns the total number of capturing groups.
///
/// This is always at least `1` since every regex has at least `1`
/// capturing group that corresponds to the entire match.
#[inline]
pub fn len(&self) -> usize {
self.0.len()
}
/// An alias for the `get` method for backwards compatibility.
///
/// Previously, we exported `get` as `pos` in an undocumented API. To
/// prevent breaking that code (e.g., in `regex-capi`), we continue
/// re-exporting the same undocumented API.
#[doc(hidden)]
#[inline]
pub fn pos(&self, i: usize) -> Option<(usize, usize)> {
self.get(i)
}
}
/// Captures represents a group of captured strings for a single match.
///
/// The 0th capture always corresponds to the entire match. Each subsequent
/// index corresponds to the next capture group in the regex. If a capture
/// group is named, then the matched string is *also* available via the `name`
/// method. (Note that the 0th capture is always unnamed and so must be
/// accessed with the `get` method.)
///
/// Positions returned from a capture group are always byte indices.
///
/// `'t` is the lifetime of the matched text.
pub struct Captures<'t> {
text: &'t str,
locs: re_trait::Locations,
named_groups: Arc<HashMap<String, usize>>,
}
impl<'t> Captures<'t> {
/// Returns the match associated with the capture group at index `i`. If
/// `i` does not correspond to a capture group, or if the capture group
/// did not participate in the match, then `None` is returned.
///
/// # Examples
///
/// Get the text of the match with a default of an empty string if this
/// group didn't participate in the match:
///
/// ```rust
/// # use regex::Regex;
/// let re = Regex::new(r"[a-z]+(?:([0-9]+)|([A-Z]+))").unwrap();
/// let caps = re.captures("abc123").unwrap();
///
/// let text1 = caps.get(1).map_or("", |m| m.as_str());
/// let text2 = caps.get(2).map_or("", |m| m.as_str());
/// assert_eq!(text1, "123");
/// assert_eq!(text2, "");
/// ```
pub fn get(&self, i: usize) -> Option<Match<'t>> {
self.locs.pos(i).map(|(s, e)| Match::new(self.text, s, e))
}
/// Returns the match for the capture group named `name`. If `name` isn't a
/// valid capture group or didn't match anything, then `None` is returned.
pub fn name(&self, name: &str) -> Option<Match<'t>> {
self.named_groups.get(name).and_then(|&i| self.get(i))
}
/// An iterator that yields all capturing matches in the order in which
/// they appear in the regex. If a particular capture group didn't
/// participate in the match, then `None` is yielded for that capture.
///
/// The first match always corresponds to the overall match of the regex.
pub fn iter<'c>(&'c self) -> SubCaptureMatches<'c, 't> {
SubCaptureMatches { caps: self, it: self.locs.iter() }
}
/// Expands all instances of `$name` in `replacement` to the corresponding
/// capture group `name`, and writes them to the `dst` buffer given.
///
/// `name` may be an integer corresponding to the index of the
/// capture group (counted by order of opening parenthesis where `0` is the
/// entire match) or it can be a name (consisting of letters, digits or
/// underscores) corresponding to a named capture group.
///
/// If `name` isn't a valid capture group (whether the name doesn't exist
/// or isn't a valid index), then it is replaced with the empty string.
///
/// The longest possible name is used. e.g., `$1a` looks up the capture
/// group named `1a` and not the capture group at index `1`. To exert more
/// precise control over the name, use braces, e.g., `${1}a`.
///
/// To write a literal `$` use `$$`.
pub fn expand(&self, replacement: &str, dst: &mut String) {
expand_str(self, replacement, dst)
}
/// Returns the number of captured groups.
///
/// This is always at least `1`, since every regex has at least one capture
/// group that corresponds to the full match.
#[inline]
pub fn len(&self) -> usize {
self.locs.len()
}
}
impl<'t> fmt::Debug for Captures<'t> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_tuple("Captures").field(&CapturesDebug(self)).finish()
}
}
struct CapturesDebug<'c, 't: 'c>(&'c Captures<'t>);
impl<'c, 't> fmt::Debug for CapturesDebug<'c, 't> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
// We'd like to show something nice here, even if it means an
// allocation to build a reverse index.
let slot_to_name: HashMap<&usize, &String> =
self.0.named_groups.iter().map(|(a, b)| (b, a)).collect();
let mut map = f.debug_map();
for (slot, m) in self.0.locs.iter().enumerate() {
let m = m.map(|(s, e)| &self.0.text[s..e]);
if let Some(name) = slot_to_name.get(&slot) {
map.entry(&name, &m);
} else {
map.entry(&slot, &m);
}
}
map.finish()
}
}
/// Get a group by index.
///
/// `'t` is the lifetime of the matched text.
///
/// The text can't outlive the `Captures` object if this method is
/// used, because of how `Index` is defined (normally `a[i]` is part
/// of `a` and can't outlive it); to do that, use `get()` instead.
///
/// # Panics
///
/// If there is no group at the given index.
impl<'t> Index<usize> for Captures<'t> {
type Output = str;
fn index(&self, i: usize) -> &str {
self.get(i)
.map(|m| m.as_str())
.unwrap_or_else(|| panic!("no group at index '{}'", i))
}
}
/// Get a group by name.
///
/// `'t` is the lifetime of the matched text and `'i` is the lifetime
/// of the group name (the index).
///
/// The text can't outlive the `Captures` object if this method is
/// used, because of how `Index` is defined (normally `a[i]` is part
/// of `a` and can't outlive it); to do that, use `name` instead.
///
/// # Panics
///
/// If there is no group named by the given value.
impl<'t, 'i> Index<&'i str> for Captures<'t> {
type Output = str;
fn index<'a>(&'a self, name: &'i str) -> &'a str {
self.name(name)
.map(|m| m.as_str())
.unwrap_or_else(|| panic!("no group named '{}'", name))
}
}
/// An iterator that yields all capturing matches in the order in which they
/// appear in the regex.
///
/// If a particular capture group didn't participate in the match, then `None`
/// is yielded for that capture. The first match always corresponds to the
/// overall match of the regex.
///
/// The lifetime `'c` corresponds to the lifetime of the `Captures` value, and
/// the lifetime `'t` corresponds to the originally matched text.
pub struct SubCaptureMatches<'c, 't: 'c> {
caps: &'c Captures<'t>,
it: SubCapturesPosIter<'c>,
}
impl<'c, 't> Iterator for SubCaptureMatches<'c, 't> {
type Item = Option<Match<'t>>;
fn next(&mut self) -> Option<Option<Match<'t>>> {
self.it
.next()
.map(|cap| cap.map(|(s, e)| Match::new(self.caps.text, s, e)))
}
}
/// An iterator that yields all non-overlapping capture groups matching a
/// particular regular expression.
///
/// The iterator stops when no more matches can be found.
///
/// `'r` is the lifetime of the compiled regular expression and `'t` is the
/// lifetime of the matched string.
pub struct CaptureMatches<'r, 't>(
re_trait::CaptureMatches<'t, ExecNoSyncStr<'r>>,
);
impl<'r, 't> Iterator for CaptureMatches<'r, 't> {
type Item = Captures<'t>;
fn next(&mut self) -> Option<Captures<'t>> {
self.0.next().map(|locs| Captures {
text: self.0.text(),
locs: locs,
named_groups: self.0.regex().capture_name_idx().clone(),
})
}
}
/// An iterator over all non-overlapping matches for a particular string.
///
/// The iterator yields a `Match` value. The iterator stops when no more
/// matches can be found.
///
/// `'r` is the lifetime of the compiled regular expression and `'t` is the
/// lifetime of the matched string.
pub struct Matches<'r, 't>(re_trait::Matches<'t, ExecNoSyncStr<'r>>);
impl<'r, 't> Iterator for Matches<'r, 't> {
type Item = Match<'t>;
fn next(&mut self) -> Option<Match<'t>> {
let text = self.0.text();
self.0.next().map(|(s, e)| Match::new(text, s, e))
}
}
/// Replacer describes types that can be used to replace matches in a string.
///
/// In general, users of this crate shouldn't need to implement this trait,
/// since implementations are already provided for `&str` and
/// `FnMut(&Captures) -> String` (or any `FnMut(&Captures) -> T`
/// where `T: AsRef<str>`), which covers most use cases.
pub trait Replacer {
/// Appends text to `dst` to replace the current match.
///
/// The current match is represented by `caps`, which is guaranteed to
/// have a match at capture group `0`.
///
/// For example, a no-op replacement would be
/// `dst.extend(caps.get(0).unwrap().as_str())`.
fn replace_append(&mut self, caps: &Captures, dst: &mut String);
/// Return a fixed unchanging replacement string.
///
/// When doing replacements, if access to `Captures` is not needed (e.g.,
/// the replacement byte string does not need `$` expansion), then it can
/// be beneficial to avoid finding sub-captures.
///
/// In general, this is called once for every call to `replacen`.
fn no_expansion<'r>(&'r mut self) -> Option<Cow<'r, str>> {
None
}
/// Return a `Replacer` that borrows and wraps this `Replacer`.
///
/// This is useful when you want to take a generic `Replacer` (which might
/// not be cloneable) and use it without consuming it, so it can be used
/// more than once.
///
/// # Example
///
/// ```
/// use regex::{Regex, Replacer};
///
/// fn replace_all_twice<R: Replacer>(
/// re: Regex,
/// src: &str,
/// mut rep: R,
/// ) -> String {
/// let dst = re.replace_all(src, rep.by_ref());
/// let dst = re.replace_all(&dst, rep.by_ref());
/// dst.into_owned()
/// }
/// ```
fn by_ref<'r>(&'r mut self) -> ReplacerRef<'r, Self> {
ReplacerRef(self)
}
}
/// By-reference adaptor for a `Replacer`
///
/// Returned by [`Replacer::by_ref`](trait.Replacer.html#method.by_ref).
#[derive(Debug)]
pub struct ReplacerRef<'a, R: ?Sized + 'a>(&'a mut R);
impl<'a, R: Replacer + ?Sized + 'a> Replacer for ReplacerRef<'a, R> {
fn replace_append(&mut self, caps: &Captures, dst: &mut String) {
self.0.replace_append(caps, dst)
}
fn no_expansion(&mut self) -> Option<Cow<str>> {
self.0.no_expansion()
}
}
impl<'a> Replacer for &'a str {
fn replace_append(&mut self, caps: &Captures, dst: &mut String) {
caps.expand(*self, dst);
}
fn no_expansion(&mut self) -> Option<Cow<str>> {
match find_byte(b'$', self.as_bytes()) {
Some(_) => None,
None => Some(Cow::Borrowed(*self)),
}
}
}
impl<F, T> Replacer for F
where
F: FnMut(&Captures) -> T,
T: AsRef<str>,
{
fn replace_append(&mut self, caps: &Captures, dst: &mut String) {
dst.push_str((*self)(caps).as_ref());
}
}
/// `NoExpand` indicates literal string replacement.
///
/// It can be used with `replace` and `replace_all` to do a literal string
/// replacement without expanding `$name` to their corresponding capture
/// groups. This can be both convenient (to avoid escaping `$`, for example)
/// and performant (since capture groups don't need to be found).
///
/// `'t` is the lifetime of the literal text.
pub struct NoExpand<'t>(pub &'t str);
impl<'t> Replacer for NoExpand<'t> {
fn replace_append(&mut self, _: &Captures, dst: &mut String) {
dst.push_str(self.0);
}
fn no_expansion(&mut self) -> Option<Cow<str>> {
Some(Cow::Borrowed(self.0))
}
}
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