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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
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tree173a775858bd501c378080a10dca74132f05bc50 /vendor/regex/src/lib.rs
parentInitial commit. (diff)
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Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+/*!
+This crate provides a library for parsing, compiling, and executing regular
+expressions. Its syntax is similar to Perl-style regular expressions, but lacks
+a few features like look around and backreferences. In exchange, all searches
+execute in linear time with respect to the size of the regular expression and
+search text.
+
+This crate's documentation provides some simple examples, describes
+[Unicode support](#unicode) and exhaustively lists the
+[supported syntax](#syntax).
+
+For more specific details on the API for regular expressions, please see the
+documentation for the [`Regex`](struct.Regex.html) type.
+
+# Usage
+
+This crate is [on crates.io](https://crates.io/crates/regex) and can be
+used by adding `regex` to your dependencies in your project's `Cargo.toml`.
+
+```toml
+[dependencies]
+regex = "1"
+```
+
+# Example: find a date
+
+General use of regular expressions in this package involves compiling an
+expression and then using it to search, split or replace text. For example,
+to confirm that some text resembles a date:
+
+```rust
+use regex::Regex;
+let re = Regex::new(r"^\d{4}-\d{2}-\d{2}$").unwrap();
+assert!(re.is_match("2014-01-01"));
+```
+
+Notice the use of the `^` and `$` anchors. In this crate, every expression
+is executed with an implicit `.*?` at the beginning and end, which allows
+it to match anywhere in the text. Anchors can be used to ensure that the
+full text matches an expression.
+
+This example also demonstrates the utility of
+[raw strings](https://doc.rust-lang.org/stable/reference/tokens.html#raw-string-literals)
+in Rust, which
+are just like regular strings except they are prefixed with an `r` and do
+not process any escape sequences. For example, `"\\d"` is the same
+expression as `r"\d"`.
+
+# Example: Avoid compiling the same regex in a loop
+
+It is an anti-pattern to compile the same regular expression in a loop
+since compilation is typically expensive. (It takes anywhere from a few
+microseconds to a few **milliseconds** depending on the size of the
+regex.) Not only is compilation itself expensive, but this also prevents
+optimizations that reuse allocations internally to the matching engines.
+
+In Rust, it can sometimes be a pain to pass regular expressions around if
+they're used from inside a helper function. Instead, we recommend using the
+[`lazy_static`](https://crates.io/crates/lazy_static) crate to ensure that
+regular expressions are compiled exactly once.
+
+For example:
+
+```rust
+use lazy_static::lazy_static;
+use regex::Regex;
+
+fn some_helper_function(text: &str) -> bool {
+ lazy_static! {
+ static ref RE: Regex = Regex::new("...").unwrap();
+ }
+ RE.is_match(text)
+}
+
+fn main() {}
+```
+
+Specifically, in this example, the regex will be compiled when it is used for
+the first time. On subsequent uses, it will reuse the previous compilation.
+
+# Example: iterating over capture groups
+
+This crate provides convenient iterators for matching an expression
+repeatedly against a search string to find successive non-overlapping
+matches. For example, to find all dates in a string and be able to access
+them by their component pieces:
+
+```rust
+# use regex::Regex;
+# fn main() {
+let re = Regex::new(r"(\d{4})-(\d{2})-(\d{2})").unwrap();
+let text = "2012-03-14, 2013-01-01 and 2014-07-05";
+for cap in re.captures_iter(text) {
+ println!("Month: {} Day: {} Year: {}", &cap[2], &cap[3], &cap[1]);
+}
+// Output:
+// Month: 03 Day: 14 Year: 2012
+// Month: 01 Day: 01 Year: 2013
+// Month: 07 Day: 05 Year: 2014
+# }
+```
+
+Notice that the year is in the capture group indexed at `1`. This is
+because the *entire match* is stored in the capture group at index `0`.
+
+# Example: replacement with named capture groups
+
+Building on the previous example, perhaps we'd like to rearrange the date
+formats. This can be done with text replacement. But to make the code
+clearer, we can *name* our capture groups and use those names as variables
+in our replacement text:
+
+```rust
+# use regex::Regex;
+# fn main() {
+let re = Regex::new(r"(?P<y>\d{4})-(?P<m>\d{2})-(?P<d>\d{2})").unwrap();
+let before = "2012-03-14, 2013-01-01 and 2014-07-05";
+let after = re.replace_all(before, "$m/$d/$y");
+assert_eq!(after, "03/14/2012, 01/01/2013 and 07/05/2014");
+# }
+```
+
+The `replace` methods are actually polymorphic in the replacement, which
+provides more flexibility than is seen here. (See the documentation for
+`Regex::replace` for more details.)
+
+Note that if your regex gets complicated, you can use the `x` flag to
+enable insignificant whitespace mode, which also lets you write comments:
+
+```rust
+# use regex::Regex;
+# fn main() {
+let re = Regex::new(r"(?x)
+ (?P<y>\d{4}) # the year
+ -
+ (?P<m>\d{2}) # the month
+ -
+ (?P<d>\d{2}) # the day
+").unwrap();
+let before = "2012-03-14, 2013-01-01 and 2014-07-05";
+let after = re.replace_all(before, "$m/$d/$y");
+assert_eq!(after, "03/14/2012, 01/01/2013 and 07/05/2014");
+# }
+```
+
+If you wish to match against whitespace in this mode, you can still use `\s`,
+`\n`, `\t`, etc. For escaping a single space character, you can escape it
+directly with `\ `, use its hex character code `\x20` or temporarily disable
+the `x` flag, e.g., `(?-x: )`.
+
+# Example: match multiple regular expressions simultaneously
+
+This demonstrates how to use a `RegexSet` to match multiple (possibly
+overlapping) regular expressions in a single scan of the search text:
+
+```rust
+use regex::RegexSet;
+
+let set = RegexSet::new(&[
+ r"\w+",
+ r"\d+",
+ r"\pL+",
+ r"foo",
+ r"bar",
+ r"barfoo",
+ r"foobar",
+]).unwrap();
+
+// Iterate over and collect all of the matches.
+let matches: Vec<_> = set.matches("foobar").into_iter().collect();
+assert_eq!(matches, vec![0, 2, 3, 4, 6]);
+
+// You can also test whether a particular regex matched:
+let matches = set.matches("foobar");
+assert!(!matches.matched(5));
+assert!(matches.matched(6));
+```
+
+# Pay for what you use
+
+With respect to searching text with a regular expression, there are three
+questions that can be asked:
+
+1. Does the text match this expression?
+2. If so, where does it match?
+3. Where did the capturing groups match?
+
+Generally speaking, this crate could provide a function to answer only #3,
+which would subsume #1 and #2 automatically. However, it can be significantly
+more expensive to compute the location of capturing group matches, so it's best
+not to do it if you don't need to.
+
+Therefore, only use what you need. For example, don't use `find` if you
+only need to test if an expression matches a string. (Use `is_match`
+instead.)
+
+# Unicode
+
+This implementation executes regular expressions **only** on valid UTF-8
+while exposing match locations as byte indices into the search string. (To
+relax this restriction, use the [`bytes`](bytes/index.html) sub-module.)
+
+Only simple case folding is supported. Namely, when matching
+case-insensitively, the characters are first mapped using the "simple" case
+folding rules defined by Unicode.
+
+Regular expressions themselves are **only** interpreted as a sequence of
+Unicode scalar values. This means you can use Unicode characters directly
+in your expression:
+
+```rust
+# use regex::Regex;
+# fn main() {
+let re = Regex::new(r"(?i)Δ+").unwrap();
+let mat = re.find("ΔδΔ").unwrap();
+assert_eq!((mat.start(), mat.end()), (0, 6));
+# }
+```
+
+Most features of the regular expressions in this crate are Unicode aware. Here
+are some examples:
+
+* `.` will match any valid UTF-8 encoded Unicode scalar value except for `\n`.
+ (To also match `\n`, enable the `s` flag, e.g., `(?s:.)`.)
+* `\w`, `\d` and `\s` are Unicode aware. For example, `\s` will match all forms
+ of whitespace categorized by Unicode.
+* `\b` matches a Unicode word boundary.
+* Negated character classes like `[^a]` match all Unicode scalar values except
+ for `a`.
+* `^` and `$` are **not** Unicode aware in multi-line mode. Namely, they only
+ recognize `\n` and not any of the other forms of line terminators defined
+ by Unicode.
+
+Unicode general categories, scripts, script extensions, ages and a smattering
+of boolean properties are available as character classes. For example, you can
+match a sequence of numerals, Greek or Cherokee letters:
+
+```rust
+# use regex::Regex;
+# fn main() {
+let re = Regex::new(r"[\pN\p{Greek}\p{Cherokee}]+").unwrap();
+let mat = re.find("abcΔᎠβⅠᏴγδⅡxyz").unwrap();
+assert_eq!((mat.start(), mat.end()), (3, 23));
+# }
+```
+
+For a more detailed breakdown of Unicode support with respect to
+[UTS#18](https://unicode.org/reports/tr18/),
+please see the
+[UNICODE](https://github.com/rust-lang/regex/blob/master/UNICODE.md)
+document in the root of the regex repository.
+
+# Opt out of Unicode support
+
+The `bytes` sub-module provides a `Regex` type that can be used to match
+on `&[u8]`. By default, text is interpreted as UTF-8 just like it is with
+the main `Regex` type. However, this behavior can be disabled by turning
+off the `u` flag, even if doing so could result in matching invalid UTF-8.
+For example, when the `u` flag is disabled, `.` will match any byte instead
+of any Unicode scalar value.
+
+Disabling the `u` flag is also possible with the standard `&str`-based `Regex`
+type, but it is only allowed where the UTF-8 invariant is maintained. For
+example, `(?-u:\w)` is an ASCII-only `\w` character class and is legal in an
+`&str`-based `Regex`, but `(?-u:\xFF)` will attempt to match the raw byte
+`\xFF`, which is invalid UTF-8 and therefore is illegal in `&str`-based
+regexes.
+
+Finally, since Unicode support requires bundling large Unicode data
+tables, this crate exposes knobs to disable the compilation of those
+data tables, which can be useful for shrinking binary size and reducing
+compilation times. For details on how to do that, see the section on [crate
+features](#crate-features).
+
+# Syntax
+
+The syntax supported in this crate is documented below.
+
+Note that the regular expression parser and abstract syntax are exposed in
+a separate crate, [`regex-syntax`](https://docs.rs/regex-syntax).
+
+## Matching one character
+
+<pre class="rust">
+. any character except new line (includes new line with s flag)
+\d digit (\p{Nd})
+\D not digit
+\pN One-letter name Unicode character class
+\p{Greek} Unicode character class (general category or script)
+\PN Negated one-letter name Unicode character class
+\P{Greek} negated Unicode character class (general category or script)
+</pre>
+
+### Character classes
+
+<pre class="rust">
+[xyz] A character class matching either x, y or z (union).
+[^xyz] A character class matching any character except x, y and z.
+[a-z] A character class matching any character in range a-z.
+[[:alpha:]] ASCII character class ([A-Za-z])
+[[:^alpha:]] Negated ASCII character class ([^A-Za-z])
+[x[^xyz]] Nested/grouping character class (matching any character except y and z)
+[a-y&&xyz] Intersection (matching x or y)
+[0-9&&[^4]] Subtraction using intersection and negation (matching 0-9 except 4)
+[0-9--4] Direct subtraction (matching 0-9 except 4)
+[a-g~~b-h] Symmetric difference (matching `a` and `h` only)
+[\[\]] Escaping in character classes (matching [ or ])
+</pre>
+
+Any named character class may appear inside a bracketed `[...]` character
+class. For example, `[\p{Greek}[:digit:]]` matches any Greek or ASCII
+digit. `[\p{Greek}&&\pL]` matches Greek letters.
+
+Precedence in character classes, from most binding to least:
+
+1. Ranges: `a-cd` == `[a-c]d`
+2. Union: `ab&&bc` == `[ab]&&[bc]`
+3. Intersection: `^a-z&&b` == `^[a-z&&b]`
+4. Negation
+
+## Composites
+
+<pre class="rust">
+xy concatenation (x followed by y)
+x|y alternation (x or y, prefer x)
+</pre>
+
+## Repetitions
+
+<pre class="rust">
+x* zero or more of x (greedy)
+x+ one or more of x (greedy)
+x? zero or one of x (greedy)
+x*? zero or more of x (ungreedy/lazy)
+x+? one or more of x (ungreedy/lazy)
+x?? zero or one of x (ungreedy/lazy)
+x{n,m} at least n x and at most m x (greedy)
+x{n,} at least n x (greedy)
+x{n} exactly n x
+x{n,m}? at least n x and at most m x (ungreedy/lazy)
+x{n,}? at least n x (ungreedy/lazy)
+x{n}? exactly n x
+</pre>
+
+## Empty matches
+
+<pre class="rust">
+^ the beginning of text (or start-of-line with multi-line mode)
+$ the end of text (or end-of-line with multi-line mode)
+\A only the beginning of text (even with multi-line mode enabled)
+\z only the end of text (even with multi-line mode enabled)
+\b a Unicode word boundary (\w on one side and \W, \A, or \z on other)
+\B not a Unicode word boundary
+</pre>
+
+## Grouping and flags
+
+<pre class="rust">
+(exp) numbered capture group (indexed by opening parenthesis)
+(?P&lt;name&gt;exp) named (also numbered) capture group (allowed chars: [_0-9a-zA-Z.\[\]])
+(?:exp) non-capturing group
+(?flags) set flags within current group
+(?flags:exp) set flags for exp (non-capturing)
+</pre>
+
+Flags are each a single character. For example, `(?x)` sets the flag `x`
+and `(?-x)` clears the flag `x`. Multiple flags can be set or cleared at
+the same time: `(?xy)` sets both the `x` and `y` flags and `(?x-y)` sets
+the `x` flag and clears the `y` flag.
+
+All flags are by default disabled unless stated otherwise. They are:
+
+<pre class="rust">
+i case-insensitive: letters match both upper and lower case
+m multi-line mode: ^ and $ match begin/end of line
+s allow . to match \n
+U swap the meaning of x* and x*?
+u Unicode support (enabled by default)
+x ignore whitespace and allow line comments (starting with `#`)
+</pre>
+
+Flags can be toggled within a pattern. Here's an example that matches
+case-insensitively for the first part but case-sensitively for the second part:
+
+```rust
+# use regex::Regex;
+# fn main() {
+let re = Regex::new(r"(?i)a+(?-i)b+").unwrap();
+let cap = re.captures("AaAaAbbBBBb").unwrap();
+assert_eq!(&cap[0], "AaAaAbb");
+# }
+```
+
+Notice that the `a+` matches either `a` or `A`, but the `b+` only matches
+`b`.
+
+Multi-line mode means `^` and `$` no longer match just at the beginning/end of
+the input, but at the beginning/end of lines:
+
+```
+# use regex::Regex;
+let re = Regex::new(r"(?m)^line \d+").unwrap();
+let m = re.find("line one\nline 2\n").unwrap();
+assert_eq!(m.as_str(), "line 2");
+```
+
+Note that `^` matches after new lines, even at the end of input:
+
+```
+# use regex::Regex;
+let re = Regex::new(r"(?m)^").unwrap();
+let m = re.find_iter("test\n").last().unwrap();
+assert_eq!((m.start(), m.end()), (5, 5));
+```
+
+Here is an example that uses an ASCII word boundary instead of a Unicode
+word boundary:
+
+```rust
+# use regex::Regex;
+# fn main() {
+let re = Regex::new(r"(?-u:\b).+(?-u:\b)").unwrap();
+let cap = re.captures("$$abc$$").unwrap();
+assert_eq!(&cap[0], "abc");
+# }
+```
+
+## Escape sequences
+
+<pre class="rust">
+\* literal *, works for any punctuation character: \.+*?()|[]{}^$
+\a bell (\x07)
+\f form feed (\x0C)
+\t horizontal tab
+\n new line
+\r carriage return
+\v vertical tab (\x0B)
+\123 octal character code (up to three digits) (when enabled)
+\x7F hex character code (exactly two digits)
+\x{10FFFF} any hex character code corresponding to a Unicode code point
+\u007F hex character code (exactly four digits)
+\u{7F} any hex character code corresponding to a Unicode code point
+\U0000007F hex character code (exactly eight digits)
+\U{7F} any hex character code corresponding to a Unicode code point
+</pre>
+
+## Perl character classes (Unicode friendly)
+
+These classes are based on the definitions provided in
+[UTS#18](https://www.unicode.org/reports/tr18/#Compatibility_Properties):
+
+<pre class="rust">
+\d digit (\p{Nd})
+\D not digit
+\s whitespace (\p{White_Space})
+\S not whitespace
+\w word character (\p{Alphabetic} + \p{M} + \d + \p{Pc} + \p{Join_Control})
+\W not word character
+</pre>
+
+## ASCII character classes
+
+<pre class="rust">
+[[:alnum:]] alphanumeric ([0-9A-Za-z])
+[[:alpha:]] alphabetic ([A-Za-z])
+[[:ascii:]] ASCII ([\x00-\x7F])
+[[:blank:]] blank ([\t ])
+[[:cntrl:]] control ([\x00-\x1F\x7F])
+[[:digit:]] digits ([0-9])
+[[:graph:]] graphical ([!-~])
+[[:lower:]] lower case ([a-z])
+[[:print:]] printable ([ -~])
+[[:punct:]] punctuation ([!-/:-@\[-`{-~])
+[[:space:]] whitespace ([\t\n\v\f\r ])
+[[:upper:]] upper case ([A-Z])
+[[:word:]] word characters ([0-9A-Za-z_])
+[[:xdigit:]] hex digit ([0-9A-Fa-f])
+</pre>
+
+# Crate features
+
+By default, this crate tries pretty hard to make regex matching both as fast
+as possible and as correct as it can be, within reason. This means that there
+is a lot of code dedicated to performance, the handling of Unicode data and the
+Unicode data itself. Overall, this leads to more dependencies, larger binaries
+and longer compile times. This trade off may not be appropriate in all cases,
+and indeed, even when all Unicode and performance features are disabled, one
+is still left with a perfectly serviceable regex engine that will work well
+in many cases.
+
+This crate exposes a number of features for controlling that trade off. Some
+of these features are strictly performance oriented, such that disabling them
+won't result in a loss of functionality, but may result in worse performance.
+Other features, such as the ones controlling the presence or absence of Unicode
+data, can result in a loss of functionality. For example, if one disables the
+`unicode-case` feature (described below), then compiling the regex `(?i)a`
+will fail since Unicode case insensitivity is enabled by default. Instead,
+callers must use `(?i-u)a` instead to disable Unicode case folding. Stated
+differently, enabling or disabling any of the features below can only add or
+subtract from the total set of valid regular expressions. Enabling or disabling
+a feature will never modify the match semantics of a regular expression.
+
+All features below are enabled by default.
+
+### Ecosystem features
+
+* **std** -
+ When enabled, this will cause `regex` to use the standard library. Currently,
+ disabling this feature will always result in a compilation error. It is
+ intended to add `alloc`-only support to regex in the future.
+
+### Performance features
+
+* **perf** -
+ Enables all performance related features. This feature is enabled by default
+ and will always cover all features that improve performance, even if more
+ are added in the future.
+* **perf-dfa** -
+ Enables the use of a lazy DFA for matching. The lazy DFA is used to compile
+ portions of a regex to a very fast DFA on an as-needed basis. This can
+ result in substantial speedups, usually by an order of magnitude on large
+ haystacks. The lazy DFA does not bring in any new dependencies, but it can
+ make compile times longer.
+* **perf-inline** -
+ Enables the use of aggressive inlining inside match routines. This reduces
+ the overhead of each match. The aggressive inlining, however, increases
+ compile times and binary size.
+* **perf-literal** -
+ Enables the use of literal optimizations for speeding up matches. In some
+ cases, literal optimizations can result in speedups of _several_ orders of
+ magnitude. Disabling this drops the `aho-corasick` and `memchr` dependencies.
+* **perf-cache** -
+ This feature used to enable a faster internal cache at the cost of using
+ additional dependencies, but this is no longer an option. A fast internal
+ cache is now used unconditionally with no additional dependencies. This may
+ change in the future.
+
+### Unicode features
+
+* **unicode** -
+ Enables all Unicode features. This feature is enabled by default, and will
+ always cover all Unicode features, even if more are added in the future.
+* **unicode-age** -
+ Provide the data for the
+ [Unicode `Age` property](https://www.unicode.org/reports/tr44/tr44-24.html#Character_Age).
+ This makes it possible to use classes like `\p{Age:6.0}` to refer to all
+ codepoints first introduced in Unicode 6.0
+* **unicode-bool** -
+ Provide the data for numerous Unicode boolean properties. The full list
+ is not included here, but contains properties like `Alphabetic`, `Emoji`,
+ `Lowercase`, `Math`, `Uppercase` and `White_Space`.
+* **unicode-case** -
+ Provide the data for case insensitive matching using
+ [Unicode's "simple loose matches" specification](https://www.unicode.org/reports/tr18/#Simple_Loose_Matches).
+* **unicode-gencat** -
+ Provide the data for
+ [Unicode general categories](https://www.unicode.org/reports/tr44/tr44-24.html#General_Category_Values).
+ This includes, but is not limited to, `Decimal_Number`, `Letter`,
+ `Math_Symbol`, `Number` and `Punctuation`.
+* **unicode-perl** -
+ Provide the data for supporting the Unicode-aware Perl character classes,
+ corresponding to `\w`, `\s` and `\d`. This is also necessary for using
+ Unicode-aware word boundary assertions. Note that if this feature is
+ disabled, the `\s` and `\d` character classes are still available if the
+ `unicode-bool` and `unicode-gencat` features are enabled, respectively.
+* **unicode-script** -
+ Provide the data for
+ [Unicode scripts and script extensions](https://www.unicode.org/reports/tr24/).
+ This includes, but is not limited to, `Arabic`, `Cyrillic`, `Hebrew`,
+ `Latin` and `Thai`.
+* **unicode-segment** -
+ Provide the data necessary to provide the properties used to implement the
+ [Unicode text segmentation algorithms](https://www.unicode.org/reports/tr29/).
+ This enables using classes like `\p{gcb=Extend}`, `\p{wb=Katakana}` and
+ `\p{sb=ATerm}`.
+
+
+# Untrusted input
+
+This crate can handle both untrusted regular expressions and untrusted
+search text.
+
+Untrusted regular expressions are handled by capping the size of a compiled
+regular expression.
+(See [`RegexBuilder::size_limit`](struct.RegexBuilder.html#method.size_limit).)
+Without this, it would be trivial for an attacker to exhaust your system's
+memory with expressions like `a{100}{100}{100}`.
+
+Untrusted search text is allowed because the matching engine(s) in this
+crate have time complexity `O(mn)` (with `m ~ regex` and `n ~ search
+text`), which means there's no way to cause exponential blow-up like with
+some other regular expression engines. (We pay for this by disallowing
+features like arbitrary look-ahead and backreferences.)
+
+When a DFA is used, pathological cases with exponential state blow-up are
+avoided by constructing the DFA lazily or in an "online" manner. Therefore,
+at most one new state can be created for each byte of input. This satisfies
+our time complexity guarantees, but can lead to memory growth
+proportional to the size of the input. As a stopgap, the DFA is only
+allowed to store a fixed number of states. When the limit is reached, its
+states are wiped and continues on, possibly duplicating previous work. If
+the limit is reached too frequently, it gives up and hands control off to
+another matching engine with fixed memory requirements.
+(The DFA size limit can also be tweaked. See
+[`RegexBuilder::dfa_size_limit`](struct.RegexBuilder.html#method.dfa_size_limit).)
+*/
+
+#![deny(missing_docs)]
+#![cfg_attr(feature = "pattern", feature(pattern))]
+#![warn(missing_debug_implementations)]
+
+#[cfg(not(feature = "std"))]
+compile_error!("`std` feature is currently required to build this crate");
+
+// To check README's example
+// TODO: Re-enable this once the MSRV is 1.43 or greater.
+// See: https://github.com/rust-lang/regex/issues/684
+// See: https://github.com/rust-lang/regex/issues/685
+// #[cfg(doctest)]
+// doc_comment::doctest!("../README.md");
+
+#[cfg(feature = "std")]
+pub use crate::error::Error;
+#[cfg(feature = "std")]
+pub use crate::re_builder::set_unicode::*;
+#[cfg(feature = "std")]
+pub use crate::re_builder::unicode::*;
+#[cfg(feature = "std")]
+pub use crate::re_set::unicode::*;
+#[cfg(feature = "std")]
+#[cfg(feature = "std")]
+pub use crate::re_unicode::{
+ escape, CaptureLocations, CaptureMatches, CaptureNames, Captures,
+ Locations, Match, Matches, NoExpand, Regex, Replacer, ReplacerRef, Split,
+ SplitN, SubCaptureMatches,
+};
+
+/**
+Match regular expressions on arbitrary bytes.
+
+This module provides a nearly identical API to the one found in the
+top-level of this crate. There are two important differences:
+
+1. Matching is done on `&[u8]` instead of `&str`. Additionally, `Vec<u8>`
+is used where `String` would have been used.
+2. Unicode support can be disabled even when disabling it would result in
+matching invalid UTF-8 bytes.
+
+# Example: match null terminated string
+
+This shows how to find all null-terminated strings in a slice of bytes:
+
+```rust
+# use regex::bytes::Regex;
+let re = Regex::new(r"(?-u)(?P<cstr>[^\x00]+)\x00").unwrap();
+let text = b"foo\x00bar\x00baz\x00";
+
+// Extract all of the strings without the null terminator from each match.
+// The unwrap is OK here since a match requires the `cstr` capture to match.
+let cstrs: Vec<&[u8]> =
+ re.captures_iter(text)
+ .map(|c| c.name("cstr").unwrap().as_bytes())
+ .collect();
+assert_eq!(vec![&b"foo"[..], &b"bar"[..], &b"baz"[..]], cstrs);
+```
+
+# Example: selectively enable Unicode support
+
+This shows how to match an arbitrary byte pattern followed by a UTF-8 encoded
+string (e.g., to extract a title from a Matroska file):
+
+```rust
+# use std::str;
+# use regex::bytes::Regex;
+let re = Regex::new(
+ r"(?-u)\x7b\xa9(?:[\x80-\xfe]|[\x40-\xff].)(?u:(.*))"
+).unwrap();
+let text = b"\x12\xd0\x3b\x5f\x7b\xa9\x85\xe2\x98\x83\x80\x98\x54\x76\x68\x65";
+let caps = re.captures(text).unwrap();
+
+// Notice that despite the `.*` at the end, it will only match valid UTF-8
+// because Unicode mode was enabled with the `u` flag. Without the `u` flag,
+// the `.*` would match the rest of the bytes.
+let mat = caps.get(1).unwrap();
+assert_eq!((7, 10), (mat.start(), mat.end()));
+
+// If there was a match, Unicode mode guarantees that `title` is valid UTF-8.
+let title = str::from_utf8(&caps[1]).unwrap();
+assert_eq!("☃", title);
+```
+
+In general, if the Unicode flag is enabled in a capture group and that capture
+is part of the overall match, then the capture is *guaranteed* to be valid
+UTF-8.
+
+# Syntax
+
+The supported syntax is pretty much the same as the syntax for Unicode
+regular expressions with a few changes that make sense for matching arbitrary
+bytes:
+
+1. The `u` flag can be disabled even when disabling it might cause the regex to
+match invalid UTF-8. When the `u` flag is disabled, the regex is said to be in
+"ASCII compatible" mode.
+2. In ASCII compatible mode, neither Unicode scalar values nor Unicode
+character classes are allowed.
+3. In ASCII compatible mode, Perl character classes (`\w`, `\d` and `\s`)
+revert to their typical ASCII definition. `\w` maps to `[[:word:]]`, `\d` maps
+to `[[:digit:]]` and `\s` maps to `[[:space:]]`.
+4. In ASCII compatible mode, word boundaries use the ASCII compatible `\w` to
+determine whether a byte is a word byte or not.
+5. Hexadecimal notation can be used to specify arbitrary bytes instead of
+Unicode codepoints. For example, in ASCII compatible mode, `\xFF` matches the
+literal byte `\xFF`, while in Unicode mode, `\xFF` is a Unicode codepoint that
+matches its UTF-8 encoding of `\xC3\xBF`. Similarly for octal notation when
+enabled.
+6. In ASCII compatible mode, `.` matches any *byte* except for `\n`. When the
+`s` flag is additionally enabled, `.` matches any byte.
+
+# Performance
+
+In general, one should expect performance on `&[u8]` to be roughly similar to
+performance on `&str`.
+*/
+#[cfg(feature = "std")]
+pub mod bytes {
+ pub use crate::re_builder::bytes::*;
+ pub use crate::re_builder::set_bytes::*;
+ pub use crate::re_bytes::*;
+ pub use crate::re_set::bytes::*;
+}
+
+mod backtrack;
+mod compile;
+#[cfg(feature = "perf-dfa")]
+mod dfa;
+mod error;
+mod exec;
+mod expand;
+mod find_byte;
+mod input;
+mod literal;
+#[cfg(feature = "pattern")]
+mod pattern;
+mod pikevm;
+mod pool;
+mod prog;
+mod re_builder;
+mod re_bytes;
+mod re_set;
+mod re_trait;
+mod re_unicode;
+mod sparse;
+mod utf8;
+
+/// The `internal` module exists to support suspicious activity, such as
+/// testing different matching engines and supporting the `regex-debug` CLI
+/// utility.
+#[doc(hidden)]
+#[cfg(feature = "std")]
+pub mod internal {
+ pub use crate::compile::Compiler;
+ pub use crate::exec::{Exec, ExecBuilder};
+ pub use crate::input::{Char, CharInput, Input, InputAt};
+ pub use crate::literal::LiteralSearcher;
+ pub use crate::prog::{EmptyLook, Inst, InstRanges, Program};
+}