1 use std::borrow::Cow; 2 use std::collections::HashMap; 3 use std::fmt; 4 use std::ops::{Index, Range}; 5 use std::str::FromStr; 6 use std::sync::Arc; 7 8 use find_byte::find_byte; 9 10 use error::Error; 11 use exec::{Exec, ExecNoSync}; 12 use expand::expand_bytes; 13 use re_builder::bytes::RegexBuilder; 14 use re_trait::{self, RegularExpression, SubCapturesPosIter}; 15 16 /// Match represents a single match of a regex in a haystack. 17 /// 18 /// The lifetime parameter `'t` refers to the lifetime of the matched text. 19 #[derive(Copy, Clone, Debug, Eq, PartialEq)] 20 pub struct Match<'t> { 21 text: &'t [u8], 22 start: usize, 23 end: usize, 24 } 25 26 impl<'t> Match<'t> { 27 /// Returns the starting byte offset of the match in the haystack. 28 #[inline] start(&self) -> usize29 pub fn start(&self) -> usize { 30 self.start 31 } 32 33 /// Returns the ending byte offset of the match in the haystack. 34 #[inline] end(&self) -> usize35 pub fn end(&self) -> usize { 36 self.end 37 } 38 39 /// Returns the range over the starting and ending byte offsets of the 40 /// match in the haystack. 41 #[inline] range(&self) -> Range<usize>42 pub fn range(&self) -> Range<usize> { 43 self.start..self.end 44 } 45 46 /// Returns the matched text. 47 #[inline] as_bytes(&self) -> &'t [u8]48 pub fn as_bytes(&self) -> &'t [u8] { 49 &self.text[self.range()] 50 } 51 52 /// Creates a new match from the given haystack and byte offsets. 53 #[inline] new(haystack: &'t [u8], start: usize, end: usize) -> Match<'t>54 fn new(haystack: &'t [u8], start: usize, end: usize) -> Match<'t> { 55 Match { text: haystack, start: start, end: end } 56 } 57 } 58 59 impl<'t> From<Match<'t>> for Range<usize> { from(m: Match<'t>) -> Range<usize>60 fn from(m: Match<'t>) -> Range<usize> { 61 m.range() 62 } 63 } 64 65 /// A compiled regular expression for matching arbitrary bytes. 66 /// 67 /// It can be used to search, split or replace text. All searching is done with 68 /// an implicit `.*?` at the beginning and end of an expression. To force an 69 /// expression to match the whole string (or a prefix or a suffix), you must 70 /// use an anchor like `^` or `$` (or `\A` and `\z`). 71 /// 72 /// Like the `Regex` type in the parent module, matches with this regex return 73 /// byte offsets into the search text. **Unlike** the parent `Regex` type, 74 /// these byte offsets may not correspond to UTF-8 sequence boundaries since 75 /// the regexes in this module can match arbitrary bytes. 76 #[derive(Clone)] 77 pub struct Regex(Exec); 78 79 impl fmt::Display for Regex { 80 /// Shows the original regular expression. fmt(&self, f: &mut fmt::Formatter) -> fmt::Result81 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { 82 write!(f, "{}", self.as_str()) 83 } 84 } 85 86 impl fmt::Debug for Regex { 87 /// Shows the original regular expression. fmt(&self, f: &mut fmt::Formatter) -> fmt::Result88 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { 89 fmt::Display::fmt(self, f) 90 } 91 } 92 93 /// A constructor for Regex from an Exec. 94 /// 95 /// This is hidden because Exec isn't actually part of the public API. 96 #[doc(hidden)] 97 impl From<Exec> for Regex { from(exec: Exec) -> Regex98 fn from(exec: Exec) -> Regex { 99 Regex(exec) 100 } 101 } 102 103 impl FromStr for Regex { 104 type Err = Error; 105 106 /// Attempts to parse a string into a regular expression from_str(s: &str) -> Result<Regex, Error>107 fn from_str(s: &str) -> Result<Regex, Error> { 108 Regex::new(s) 109 } 110 } 111 112 /// Core regular expression methods. 113 impl Regex { 114 /// Compiles a regular expression. Once compiled, it can be used repeatedly 115 /// to search, split or replace text in a string. 116 /// 117 /// If an invalid expression is given, then an error is returned. new(re: &str) -> Result<Regex, Error>118 pub fn new(re: &str) -> Result<Regex, Error> { 119 RegexBuilder::new(re).build() 120 } 121 122 /// Returns true if and only if the regex matches the string given. 123 /// 124 /// It is recommended to use this method if all you need to do is test 125 /// a match, since the underlying matching engine may be able to do less 126 /// work. 127 /// 128 /// # Example 129 /// 130 /// Test if some text contains at least one word with exactly 13 ASCII word 131 /// bytes: 132 /// 133 /// ```rust 134 /// # extern crate regex; use regex::bytes::Regex; 135 /// # fn main() { 136 /// let text = b"I categorically deny having triskaidekaphobia."; 137 /// assert!(Regex::new(r"\b\w{13}\b").unwrap().is_match(text)); 138 /// # } 139 /// ``` is_match(&self, text: &[u8]) -> bool140 pub fn is_match(&self, text: &[u8]) -> bool { 141 self.is_match_at(text, 0) 142 } 143 144 /// Returns the start and end byte range of the leftmost-first match in 145 /// `text`. If no match exists, then `None` is returned. 146 /// 147 /// Note that this should only be used if you want to discover the position 148 /// of the match. Testing the existence of a match is faster if you use 149 /// `is_match`. 150 /// 151 /// # Example 152 /// 153 /// Find the start and end location of the first word with exactly 13 154 /// ASCII word bytes: 155 /// 156 /// ```rust 157 /// # extern crate regex; use regex::bytes::Regex; 158 /// # fn main() { 159 /// let text = b"I categorically deny having triskaidekaphobia."; 160 /// let mat = Regex::new(r"\b\w{13}\b").unwrap().find(text).unwrap(); 161 /// assert_eq!((mat.start(), mat.end()), (2, 15)); 162 /// # } 163 /// ``` find<'t>(&self, text: &'t [u8]) -> Option<Match<'t>>164 pub fn find<'t>(&self, text: &'t [u8]) -> Option<Match<'t>> { 165 self.find_at(text, 0) 166 } 167 168 /// Returns an iterator for each successive non-overlapping match in 169 /// `text`, returning the start and end byte indices with respect to 170 /// `text`. 171 /// 172 /// # Example 173 /// 174 /// Find the start and end location of every word with exactly 13 ASCII 175 /// word bytes: 176 /// 177 /// ```rust 178 /// # extern crate regex; use regex::bytes::Regex; 179 /// # fn main() { 180 /// let text = b"Retroactively relinquishing remunerations is reprehensible."; 181 /// for mat in Regex::new(r"\b\w{13}\b").unwrap().find_iter(text) { 182 /// println!("{:?}", mat); 183 /// } 184 /// # } 185 /// ``` find_iter<'r, 't>(&'r self, text: &'t [u8]) -> Matches<'r, 't>186 pub fn find_iter<'r, 't>(&'r self, text: &'t [u8]) -> Matches<'r, 't> { 187 Matches(self.0.searcher().find_iter(text)) 188 } 189 190 /// Returns the capture groups corresponding to the leftmost-first 191 /// match in `text`. Capture group `0` always corresponds to the entire 192 /// match. If no match is found, then `None` is returned. 193 /// 194 /// You should only use `captures` if you need access to the location of 195 /// capturing group matches. Otherwise, `find` is faster for discovering 196 /// the location of the overall match. 197 /// 198 /// # Examples 199 /// 200 /// Say you have some text with movie names and their release years, 201 /// like "'Citizen Kane' (1941)". It'd be nice if we could search for text 202 /// looking like that, while also extracting the movie name and its release 203 /// year separately. 204 /// 205 /// ```rust 206 /// # extern crate regex; use regex::bytes::Regex; 207 /// # fn main() { 208 /// let re = Regex::new(r"'([^']+)'\s+\((\d{4})\)").unwrap(); 209 /// let text = b"Not my favorite movie: 'Citizen Kane' (1941)."; 210 /// let caps = re.captures(text).unwrap(); 211 /// assert_eq!(caps.get(1).unwrap().as_bytes(), &b"Citizen Kane"[..]); 212 /// assert_eq!(caps.get(2).unwrap().as_bytes(), &b"1941"[..]); 213 /// assert_eq!(caps.get(0).unwrap().as_bytes(), &b"'Citizen Kane' (1941)"[..]); 214 /// // You can also access the groups by index using the Index notation. 215 /// // Note that this will panic on an invalid index. 216 /// assert_eq!(&caps[1], b"Citizen Kane"); 217 /// assert_eq!(&caps[2], b"1941"); 218 /// assert_eq!(&caps[0], b"'Citizen Kane' (1941)"); 219 /// # } 220 /// ``` 221 /// 222 /// Note that the full match is at capture group `0`. Each subsequent 223 /// capture group is indexed by the order of its opening `(`. 224 /// 225 /// We can make this example a bit clearer by using *named* capture groups: 226 /// 227 /// ```rust 228 /// # extern crate regex; use regex::bytes::Regex; 229 /// # fn main() { 230 /// let re = Regex::new(r"'(?P<title>[^']+)'\s+\((?P<year>\d{4})\)") 231 /// .unwrap(); 232 /// let text = b"Not my favorite movie: 'Citizen Kane' (1941)."; 233 /// let caps = re.captures(text).unwrap(); 234 /// assert_eq!(caps.name("title").unwrap().as_bytes(), b"Citizen Kane"); 235 /// assert_eq!(caps.name("year").unwrap().as_bytes(), b"1941"); 236 /// assert_eq!(caps.get(0).unwrap().as_bytes(), &b"'Citizen Kane' (1941)"[..]); 237 /// // You can also access the groups by name using the Index notation. 238 /// // Note that this will panic on an invalid group name. 239 /// assert_eq!(&caps["title"], b"Citizen Kane"); 240 /// assert_eq!(&caps["year"], b"1941"); 241 /// assert_eq!(&caps[0], b"'Citizen Kane' (1941)"); 242 /// 243 /// # } 244 /// ``` 245 /// 246 /// Here we name the capture groups, which we can access with the `name` 247 /// method or the `Index` notation with a `&str`. Note that the named 248 /// capture groups are still accessible with `get` or the `Index` notation 249 /// with a `usize`. 250 /// 251 /// The `0`th capture group is always unnamed, so it must always be 252 /// accessed with `get(0)` or `[0]`. captures<'t>(&self, text: &'t [u8]) -> Option<Captures<'t>>253 pub fn captures<'t>(&self, text: &'t [u8]) -> Option<Captures<'t>> { 254 let mut locs = self.capture_locations(); 255 self.captures_read_at(&mut locs, text, 0).map(move |_| Captures { 256 text: text, 257 locs: locs.0, 258 named_groups: self.0.capture_name_idx().clone(), 259 }) 260 } 261 262 /// Returns an iterator over all the non-overlapping capture groups matched 263 /// in `text`. This is operationally the same as `find_iter`, except it 264 /// yields information about capturing group matches. 265 /// 266 /// # Example 267 /// 268 /// We can use this to find all movie titles and their release years in 269 /// some text, where the movie is formatted like "'Title' (xxxx)": 270 /// 271 /// ```rust 272 /// # extern crate regex; use std::str; use regex::bytes::Regex; 273 /// # fn main() { 274 /// let re = Regex::new(r"'(?P<title>[^']+)'\s+\((?P<year>\d{4})\)") 275 /// .unwrap(); 276 /// let text = b"'Citizen Kane' (1941), 'The Wizard of Oz' (1939), 'M' (1931)."; 277 /// for caps in re.captures_iter(text) { 278 /// let title = str::from_utf8(&caps["title"]).unwrap(); 279 /// let year = str::from_utf8(&caps["year"]).unwrap(); 280 /// println!("Movie: {:?}, Released: {:?}", title, year); 281 /// } 282 /// // Output: 283 /// // Movie: Citizen Kane, Released: 1941 284 /// // Movie: The Wizard of Oz, Released: 1939 285 /// // Movie: M, Released: 1931 286 /// # } 287 /// ``` captures_iter<'r, 't>( &'r self, text: &'t [u8], ) -> CaptureMatches<'r, 't>288 pub fn captures_iter<'r, 't>( 289 &'r self, 290 text: &'t [u8], 291 ) -> CaptureMatches<'r, 't> { 292 CaptureMatches(self.0.searcher().captures_iter(text)) 293 } 294 295 /// Returns an iterator of substrings of `text` delimited by a match of the 296 /// regular expression. Namely, each element of the iterator corresponds to 297 /// text that *isn't* matched by the regular expression. 298 /// 299 /// This method will *not* copy the text given. 300 /// 301 /// # Example 302 /// 303 /// To split a string delimited by arbitrary amounts of spaces or tabs: 304 /// 305 /// ```rust 306 /// # extern crate regex; use regex::bytes::Regex; 307 /// # fn main() { 308 /// let re = Regex::new(r"[ \t]+").unwrap(); 309 /// let fields: Vec<&[u8]> = re.split(b"a b \t c\td e").collect(); 310 /// assert_eq!(fields, vec![ 311 /// &b"a"[..], &b"b"[..], &b"c"[..], &b"d"[..], &b"e"[..], 312 /// ]); 313 /// # } 314 /// ``` split<'r, 't>(&'r self, text: &'t [u8]) -> Split<'r, 't>315 pub fn split<'r, 't>(&'r self, text: &'t [u8]) -> Split<'r, 't> { 316 Split { finder: self.find_iter(text), last: 0 } 317 } 318 319 /// Returns an iterator of at most `limit` substrings of `text` delimited 320 /// by a match of the regular expression. (A `limit` of `0` will return no 321 /// substrings.) Namely, each element of the iterator corresponds to text 322 /// that *isn't* matched by the regular expression. The remainder of the 323 /// string that is not split will be the last element in the iterator. 324 /// 325 /// This method will *not* copy the text given. 326 /// 327 /// # Example 328 /// 329 /// Get the first two words in some text: 330 /// 331 /// ```rust 332 /// # extern crate regex; use regex::bytes::Regex; 333 /// # fn main() { 334 /// let re = Regex::new(r"\W+").unwrap(); 335 /// let fields: Vec<&[u8]> = re.splitn(b"Hey! How are you?", 3).collect(); 336 /// assert_eq!(fields, vec![&b"Hey"[..], &b"How"[..], &b"are you?"[..]]); 337 /// # } 338 /// ``` splitn<'r, 't>( &'r self, text: &'t [u8], limit: usize, ) -> SplitN<'r, 't>339 pub fn splitn<'r, 't>( 340 &'r self, 341 text: &'t [u8], 342 limit: usize, 343 ) -> SplitN<'r, 't> { 344 SplitN { splits: self.split(text), n: limit } 345 } 346 347 /// Replaces the leftmost-first match with the replacement provided. The 348 /// replacement can be a regular byte string (where `$N` and `$name` are 349 /// expanded to match capture groups) or a function that takes the matches' 350 /// `Captures` and returns the replaced byte string. 351 /// 352 /// If no match is found, then a copy of the byte string is returned 353 /// unchanged. 354 /// 355 /// # Replacement string syntax 356 /// 357 /// All instances of `$name` in the replacement text is replaced with the 358 /// corresponding capture group `name`. 359 /// 360 /// `name` may be an integer corresponding to the index of the 361 /// capture group (counted by order of opening parenthesis where `0` is the 362 /// entire match) or it can be a name (consisting of letters, digits or 363 /// underscores) corresponding to a named capture group. 364 /// 365 /// If `name` isn't a valid capture group (whether the name doesn't exist 366 /// or isn't a valid index), then it is replaced with the empty string. 367 /// 368 /// The longest possible name is used. e.g., `$1a` looks up the capture 369 /// group named `1a` and not the capture group at index `1`. To exert more 370 /// precise control over the name, use braces, e.g., `${1}a`. 371 /// 372 /// To write a literal `$` use `$$`. 373 /// 374 /// # Examples 375 /// 376 /// Note that this function is polymorphic with respect to the replacement. 377 /// In typical usage, this can just be a normal byte string: 378 /// 379 /// ```rust 380 /// # extern crate regex; use regex::bytes::Regex; 381 /// # fn main() { 382 /// let re = Regex::new("[^01]+").unwrap(); 383 /// assert_eq!(re.replace(b"1078910", &b""[..]), &b"1010"[..]); 384 /// # } 385 /// ``` 386 /// 387 /// But anything satisfying the `Replacer` trait will work. For example, a 388 /// closure of type `|&Captures| -> Vec<u8>` provides direct access to the 389 /// captures corresponding to a match. This allows one to access capturing 390 /// group matches easily: 391 /// 392 /// ```rust 393 /// # extern crate regex; use regex::bytes::Regex; 394 /// # use regex::bytes::Captures; fn main() { 395 /// let re = Regex::new(r"([^,\s]+),\s+(\S+)").unwrap(); 396 /// let result = re.replace(b"Springsteen, Bruce", |caps: &Captures| { 397 /// let mut replacement = caps[2].to_owned(); 398 /// replacement.push(b' '); 399 /// replacement.extend(&caps[1]); 400 /// replacement 401 /// }); 402 /// assert_eq!(result, &b"Bruce Springsteen"[..]); 403 /// # } 404 /// ``` 405 /// 406 /// But this is a bit cumbersome to use all the time. Instead, a simple 407 /// syntax is supported that expands `$name` into the corresponding capture 408 /// group. Here's the last example, but using this expansion technique 409 /// with named capture groups: 410 /// 411 /// ```rust 412 /// # extern crate regex; use regex::bytes::Regex; 413 /// # fn main() { 414 /// let re = Regex::new(r"(?P<last>[^,\s]+),\s+(?P<first>\S+)").unwrap(); 415 /// let result = re.replace(b"Springsteen, Bruce", &b"$first $last"[..]); 416 /// assert_eq!(result, &b"Bruce Springsteen"[..]); 417 /// # } 418 /// ``` 419 /// 420 /// Note that using `$2` instead of `$first` or `$1` instead of `$last` 421 /// would produce the same result. To write a literal `$` use `$$`. 422 /// 423 /// Sometimes the replacement string requires use of curly braces to 424 /// delineate a capture group replacement and surrounding literal text. 425 /// For example, if we wanted to join two words together with an 426 /// underscore: 427 /// 428 /// ```rust 429 /// # extern crate regex; use regex::bytes::Regex; 430 /// # fn main() { 431 /// let re = Regex::new(r"(?P<first>\w+)\s+(?P<second>\w+)").unwrap(); 432 /// let result = re.replace(b"deep fried", &b"${first}_$second"[..]); 433 /// assert_eq!(result, &b"deep_fried"[..]); 434 /// # } 435 /// ``` 436 /// 437 /// Without the curly braces, the capture group name `first_` would be 438 /// used, and since it doesn't exist, it would be replaced with the empty 439 /// string. 440 /// 441 /// Finally, sometimes you just want to replace a literal string with no 442 /// regard for capturing group expansion. This can be done by wrapping a 443 /// byte string with `NoExpand`: 444 /// 445 /// ```rust 446 /// # extern crate regex; use regex::bytes::Regex; 447 /// # fn main() { 448 /// use regex::bytes::NoExpand; 449 /// 450 /// let re = Regex::new(r"(?P<last>[^,\s]+),\s+(\S+)").unwrap(); 451 /// let result = re.replace(b"Springsteen, Bruce", NoExpand(b"$2 $last")); 452 /// assert_eq!(result, &b"$2 $last"[..]); 453 /// # } 454 /// ``` replace<'t, R: Replacer>( &self, text: &'t [u8], rep: R, ) -> Cow<'t, [u8]>455 pub fn replace<'t, R: Replacer>( 456 &self, 457 text: &'t [u8], 458 rep: R, 459 ) -> Cow<'t, [u8]> { 460 self.replacen(text, 1, rep) 461 } 462 463 /// Replaces all non-overlapping matches in `text` with the replacement 464 /// provided. This is the same as calling `replacen` with `limit` set to 465 /// `0`. 466 /// 467 /// See the documentation for `replace` for details on how to access 468 /// capturing group matches in the replacement text. replace_all<'t, R: Replacer>( &self, text: &'t [u8], rep: R, ) -> Cow<'t, [u8]>469 pub fn replace_all<'t, R: Replacer>( 470 &self, 471 text: &'t [u8], 472 rep: R, 473 ) -> Cow<'t, [u8]> { 474 self.replacen(text, 0, rep) 475 } 476 477 /// Replaces at most `limit` non-overlapping matches in `text` with the 478 /// replacement provided. If `limit` is 0, then all non-overlapping matches 479 /// are replaced. 480 /// 481 /// See the documentation for `replace` for details on how to access 482 /// capturing group matches in the replacement text. replacen<'t, R: Replacer>( &self, text: &'t [u8], limit: usize, mut rep: R, ) -> Cow<'t, [u8]>483 pub fn replacen<'t, R: Replacer>( 484 &self, 485 text: &'t [u8], 486 limit: usize, 487 mut rep: R, 488 ) -> Cow<'t, [u8]> { 489 if let Some(rep) = rep.no_expansion() { 490 let mut it = self.find_iter(text).enumerate().peekable(); 491 if it.peek().is_none() { 492 return Cow::Borrowed(text); 493 } 494 let mut new = Vec::with_capacity(text.len()); 495 let mut last_match = 0; 496 for (i, m) in it { 497 if limit > 0 && i >= limit { 498 break; 499 } 500 new.extend_from_slice(&text[last_match..m.start()]); 501 new.extend_from_slice(&rep); 502 last_match = m.end(); 503 } 504 new.extend_from_slice(&text[last_match..]); 505 return Cow::Owned(new); 506 } 507 508 // The slower path, which we use if the replacement needs access to 509 // capture groups. 510 let mut it = self.captures_iter(text).enumerate().peekable(); 511 if it.peek().is_none() { 512 return Cow::Borrowed(text); 513 } 514 let mut new = Vec::with_capacity(text.len()); 515 let mut last_match = 0; 516 for (i, cap) in it { 517 if limit > 0 && i >= limit { 518 break; 519 } 520 // unwrap on 0 is OK because captures only reports matches 521 let m = cap.get(0).unwrap(); 522 new.extend_from_slice(&text[last_match..m.start()]); 523 rep.replace_append(&cap, &mut new); 524 last_match = m.end(); 525 } 526 new.extend_from_slice(&text[last_match..]); 527 Cow::Owned(new) 528 } 529 } 530 531 /// Advanced or "lower level" search methods. 532 impl Regex { 533 /// Returns the end location of a match in the text given. 534 /// 535 /// This method may have the same performance characteristics as 536 /// `is_match`, except it provides an end location for a match. In 537 /// particular, the location returned *may be shorter* than the proper end 538 /// of the leftmost-first match. 539 /// 540 /// # Example 541 /// 542 /// Typically, `a+` would match the entire first sequence of `a` in some 543 /// text, but `shortest_match` can give up as soon as it sees the first 544 /// `a`. 545 /// 546 /// ```rust 547 /// # extern crate regex; use regex::bytes::Regex; 548 /// # fn main() { 549 /// let text = b"aaaaa"; 550 /// let pos = Regex::new(r"a+").unwrap().shortest_match(text); 551 /// assert_eq!(pos, Some(1)); 552 /// # } 553 /// ``` shortest_match(&self, text: &[u8]) -> Option<usize>554 pub fn shortest_match(&self, text: &[u8]) -> Option<usize> { 555 self.shortest_match_at(text, 0) 556 } 557 558 /// Returns the same as shortest_match, but starts the search at the given 559 /// offset. 560 /// 561 /// The significance of the starting point is that it takes the surrounding 562 /// context into consideration. For example, the `\A` anchor can only 563 /// match when `start == 0`. shortest_match_at( &self, text: &[u8], start: usize, ) -> Option<usize>564 pub fn shortest_match_at( 565 &self, 566 text: &[u8], 567 start: usize, 568 ) -> Option<usize> { 569 self.0.searcher().shortest_match_at(text, start) 570 } 571 572 /// Returns the same as is_match, but starts the search at the given 573 /// offset. 574 /// 575 /// The significance of the starting point is that it takes the surrounding 576 /// context into consideration. For example, the `\A` anchor can only 577 /// match when `start == 0`. is_match_at(&self, text: &[u8], start: usize) -> bool578 pub fn is_match_at(&self, text: &[u8], start: usize) -> bool { 579 self.shortest_match_at(text, start).is_some() 580 } 581 582 /// Returns the same as find, but starts the search at the given 583 /// offset. 584 /// 585 /// The significance of the starting point is that it takes the surrounding 586 /// context into consideration. For example, the `\A` anchor can only 587 /// match when `start == 0`. find_at<'t>( &self, text: &'t [u8], start: usize, ) -> Option<Match<'t>>588 pub fn find_at<'t>( 589 &self, 590 text: &'t [u8], 591 start: usize, 592 ) -> Option<Match<'t>> { 593 self.0 594 .searcher() 595 .find_at(text, start) 596 .map(|(s, e)| Match::new(text, s, e)) 597 } 598 599 /// This is like `captures`, but uses 600 /// [`CaptureLocations`](struct.CaptureLocations.html) 601 /// instead of 602 /// [`Captures`](struct.Captures.html) in order to amortize allocations. 603 /// 604 /// To create a `CaptureLocations` value, use the 605 /// `Regex::capture_locations` method. 606 /// 607 /// This returns the overall match if this was successful, which is always 608 /// equivalence to the `0`th capture group. captures_read<'t>( &self, locs: &mut CaptureLocations, text: &'t [u8], ) -> Option<Match<'t>>609 pub fn captures_read<'t>( 610 &self, 611 locs: &mut CaptureLocations, 612 text: &'t [u8], 613 ) -> Option<Match<'t>> { 614 self.captures_read_at(locs, text, 0) 615 } 616 617 /// Returns the same as `captures_read`, but starts the search at the given 618 /// offset and populates the capture locations given. 619 /// 620 /// The significance of the starting point is that it takes the surrounding 621 /// context into consideration. For example, the `\A` anchor can only 622 /// match when `start == 0`. captures_read_at<'t>( &self, locs: &mut CaptureLocations, text: &'t [u8], start: usize, ) -> Option<Match<'t>>623 pub fn captures_read_at<'t>( 624 &self, 625 locs: &mut CaptureLocations, 626 text: &'t [u8], 627 start: usize, 628 ) -> Option<Match<'t>> { 629 self.0 630 .searcher() 631 .captures_read_at(&mut locs.0, text, start) 632 .map(|(s, e)| Match::new(text, s, e)) 633 } 634 635 /// An undocumented alias for `captures_read_at`. 636 /// 637 /// The `regex-capi` crate previously used this routine, so to avoid 638 /// breaking that crate, we continue to provide the name as an undocumented 639 /// alias. 640 #[doc(hidden)] read_captures_at<'t>( &self, locs: &mut CaptureLocations, text: &'t [u8], start: usize, ) -> Option<Match<'t>>641 pub fn read_captures_at<'t>( 642 &self, 643 locs: &mut CaptureLocations, 644 text: &'t [u8], 645 start: usize, 646 ) -> Option<Match<'t>> { 647 self.captures_read_at(locs, text, start) 648 } 649 } 650 651 /// Auxiliary methods. 652 impl Regex { 653 /// Returns the original string of this regex. as_str(&self) -> &str654 pub fn as_str(&self) -> &str { 655 &self.0.regex_strings()[0] 656 } 657 658 /// Returns an iterator over the capture names. capture_names(&self) -> CaptureNames659 pub fn capture_names(&self) -> CaptureNames { 660 CaptureNames(self.0.capture_names().iter()) 661 } 662 663 /// Returns the number of captures. captures_len(&self) -> usize664 pub fn captures_len(&self) -> usize { 665 self.0.capture_names().len() 666 } 667 668 /// Returns an empty set of capture locations that can be reused in 669 /// multiple calls to `captures_read` or `captures_read_at`. capture_locations(&self) -> CaptureLocations670 pub fn capture_locations(&self) -> CaptureLocations { 671 CaptureLocations(self.0.searcher().locations()) 672 } 673 674 /// An alias for `capture_locations` to preserve backward compatibility. 675 /// 676 /// The `regex-capi` crate uses this method, so to avoid breaking that 677 /// crate, we continue to export it as an undocumented API. 678 #[doc(hidden)] locations(&self) -> CaptureLocations679 pub fn locations(&self) -> CaptureLocations { 680 CaptureLocations(self.0.searcher().locations()) 681 } 682 } 683 684 /// An iterator over all non-overlapping matches for a particular string. 685 /// 686 /// The iterator yields a tuple of integers corresponding to the start and end 687 /// of the match. The indices are byte offsets. The iterator stops when no more 688 /// matches can be found. 689 /// 690 /// `'r` is the lifetime of the compiled regular expression and `'t` is the 691 /// lifetime of the matched byte string. 692 pub struct Matches<'r, 't>(re_trait::Matches<'t, ExecNoSync<'r>>); 693 694 impl<'r, 't> Iterator for Matches<'r, 't> { 695 type Item = Match<'t>; 696 next(&mut self) -> Option<Match<'t>>697 fn next(&mut self) -> Option<Match<'t>> { 698 let text = self.0.text(); 699 self.0.next().map(|(s, e)| Match::new(text, s, e)) 700 } 701 } 702 703 /// An iterator that yields all non-overlapping capture groups matching a 704 /// particular regular expression. 705 /// 706 /// The iterator stops when no more matches can be found. 707 /// 708 /// `'r` is the lifetime of the compiled regular expression and `'t` is the 709 /// lifetime of the matched byte string. 710 pub struct CaptureMatches<'r, 't>( 711 re_trait::CaptureMatches<'t, ExecNoSync<'r>>, 712 ); 713 714 impl<'r, 't> Iterator for CaptureMatches<'r, 't> { 715 type Item = Captures<'t>; 716 next(&mut self) -> Option<Captures<'t>>717 fn next(&mut self) -> Option<Captures<'t>> { 718 self.0.next().map(|locs| Captures { 719 text: self.0.text(), 720 locs: locs, 721 named_groups: self.0.regex().capture_name_idx().clone(), 722 }) 723 } 724 } 725 726 /// Yields all substrings delimited by a regular expression match. 727 /// 728 /// `'r` is the lifetime of the compiled regular expression and `'t` is the 729 /// lifetime of the byte string being split. 730 pub struct Split<'r, 't> { 731 finder: Matches<'r, 't>, 732 last: usize, 733 } 734 735 impl<'r, 't> Iterator for Split<'r, 't> { 736 type Item = &'t [u8]; 737 next(&mut self) -> Option<&'t [u8]>738 fn next(&mut self) -> Option<&'t [u8]> { 739 let text = self.finder.0.text(); 740 match self.finder.next() { 741 None => { 742 if self.last > text.len() { 743 None 744 } else { 745 let s = &text[self.last..]; 746 self.last = text.len() + 1; // Next call will return None 747 Some(s) 748 } 749 } 750 Some(m) => { 751 let matched = &text[self.last..m.start()]; 752 self.last = m.end(); 753 Some(matched) 754 } 755 } 756 } 757 } 758 759 /// Yields at most `N` substrings delimited by a regular expression match. 760 /// 761 /// The last substring will be whatever remains after splitting. 762 /// 763 /// `'r` is the lifetime of the compiled regular expression and `'t` is the 764 /// lifetime of the byte string being split. 765 pub struct SplitN<'r, 't> { 766 splits: Split<'r, 't>, 767 n: usize, 768 } 769 770 impl<'r, 't> Iterator for SplitN<'r, 't> { 771 type Item = &'t [u8]; 772 next(&mut self) -> Option<&'t [u8]>773 fn next(&mut self) -> Option<&'t [u8]> { 774 if self.n == 0 { 775 return None; 776 } 777 778 self.n -= 1; 779 if self.n > 0 { 780 return self.splits.next(); 781 } 782 783 let text = self.splits.finder.0.text(); 784 if self.splits.last > text.len() { 785 // We've already returned all substrings. 786 None 787 } else { 788 // self.n == 0, so future calls will return None immediately 789 Some(&text[self.splits.last..]) 790 } 791 } 792 } 793 794 /// An iterator over the names of all possible captures. 795 /// 796 /// `None` indicates an unnamed capture; the first element (capture 0, the 797 /// whole matched region) is always unnamed. 798 /// 799 /// `'r` is the lifetime of the compiled regular expression. 800 pub struct CaptureNames<'r>(::std::slice::Iter<'r, Option<String>>); 801 802 impl<'r> Iterator for CaptureNames<'r> { 803 type Item = Option<&'r str>; 804 next(&mut self) -> Option<Option<&'r str>>805 fn next(&mut self) -> Option<Option<&'r str>> { 806 self.0 807 .next() 808 .as_ref() 809 .map(|slot| slot.as_ref().map(|name| name.as_ref())) 810 } 811 size_hint(&self) -> (usize, Option<usize>)812 fn size_hint(&self) -> (usize, Option<usize>) { 813 self.0.size_hint() 814 } 815 } 816 817 /// CaptureLocations is a low level representation of the raw offsets of each 818 /// submatch. 819 /// 820 /// You can think of this as a lower level 821 /// [`Captures`](struct.Captures.html), where this type does not support 822 /// named capturing groups directly and it does not borrow the text that these 823 /// offsets were matched on. 824 /// 825 /// Primarily, this type is useful when using the lower level `Regex` APIs 826 /// such as `read_captures`, which permits amortizing the allocation in which 827 /// capture match locations are stored. 828 /// 829 /// In order to build a value of this type, you'll need to call the 830 /// `capture_locations` method on the `Regex` being used to execute the search. 831 /// The value returned can then be reused in subsequent searches. 832 #[derive(Clone, Debug)] 833 pub struct CaptureLocations(re_trait::Locations); 834 835 /// A type alias for `CaptureLocations` for backwards compatibility. 836 /// 837 /// Previously, we exported `CaptureLocations` as `Locations` in an 838 /// undocumented API. To prevent breaking that code (e.g., in `regex-capi`), 839 /// we continue re-exporting the same undocumented API. 840 #[doc(hidden)] 841 pub type Locations = CaptureLocations; 842 843 impl CaptureLocations { 844 /// Returns the start and end positions of the Nth capture group. Returns 845 /// `None` if `i` is not a valid capture group or if the capture group did 846 /// not match anything. The positions returned are *always* byte indices 847 /// with respect to the original string matched. 848 #[inline] get(&self, i: usize) -> Option<(usize, usize)>849 pub fn get(&self, i: usize) -> Option<(usize, usize)> { 850 self.0.pos(i) 851 } 852 853 /// Returns the total number of capturing groups. 854 /// 855 /// This is always at least `1` since every regex has at least `1` 856 /// capturing group that corresponds to the entire match. 857 #[inline] len(&self) -> usize858 pub fn len(&self) -> usize { 859 self.0.len() 860 } 861 862 /// An alias for the `get` method for backwards compatibility. 863 /// 864 /// Previously, we exported `get` as `pos` in an undocumented API. To 865 /// prevent breaking that code (e.g., in `regex-capi`), we continue 866 /// re-exporting the same undocumented API. 867 #[doc(hidden)] 868 #[inline] pos(&self, i: usize) -> Option<(usize, usize)>869 pub fn pos(&self, i: usize) -> Option<(usize, usize)> { 870 self.get(i) 871 } 872 } 873 874 /// Captures represents a group of captured byte strings for a single match. 875 /// 876 /// The 0th capture always corresponds to the entire match. Each subsequent 877 /// index corresponds to the next capture group in the regex. If a capture 878 /// group is named, then the matched byte string is *also* available via the 879 /// `name` method. (Note that the 0th capture is always unnamed and so must be 880 /// accessed with the `get` method.) 881 /// 882 /// Positions returned from a capture group are always byte indices. 883 /// 884 /// `'t` is the lifetime of the matched text. 885 pub struct Captures<'t> { 886 text: &'t [u8], 887 locs: re_trait::Locations, 888 named_groups: Arc<HashMap<String, usize>>, 889 } 890 891 impl<'t> Captures<'t> { 892 /// Returns the match associated with the capture group at index `i`. If 893 /// `i` does not correspond to a capture group, or if the capture group 894 /// did not participate in the match, then `None` is returned. 895 /// 896 /// # Examples 897 /// 898 /// Get the text of the match with a default of an empty string if this 899 /// group didn't participate in the match: 900 /// 901 /// ```rust 902 /// # use regex::bytes::Regex; 903 /// let re = Regex::new(r"[a-z]+(?:([0-9]+)|([A-Z]+))").unwrap(); 904 /// let caps = re.captures(b"abc123").unwrap(); 905 /// 906 /// let text1 = caps.get(1).map_or(&b""[..], |m| m.as_bytes()); 907 /// let text2 = caps.get(2).map_or(&b""[..], |m| m.as_bytes()); 908 /// assert_eq!(text1, &b"123"[..]); 909 /// assert_eq!(text2, &b""[..]); 910 /// ``` get(&self, i: usize) -> Option<Match<'t>>911 pub fn get(&self, i: usize) -> Option<Match<'t>> { 912 self.locs.pos(i).map(|(s, e)| Match::new(self.text, s, e)) 913 } 914 915 /// Returns the match for the capture group named `name`. If `name` isn't a 916 /// valid capture group or didn't match anything, then `None` is returned. name(&self, name: &str) -> Option<Match<'t>>917 pub fn name(&self, name: &str) -> Option<Match<'t>> { 918 self.named_groups.get(name).and_then(|&i| self.get(i)) 919 } 920 921 /// An iterator that yields all capturing matches in the order in which 922 /// they appear in the regex. If a particular capture group didn't 923 /// participate in the match, then `None` is yielded for that capture. 924 /// 925 /// The first match always corresponds to the overall match of the regex. iter<'c>(&'c self) -> SubCaptureMatches<'c, 't>926 pub fn iter<'c>(&'c self) -> SubCaptureMatches<'c, 't> { 927 SubCaptureMatches { caps: self, it: self.locs.iter() } 928 } 929 930 /// Expands all instances of `$name` in `replacement` to the corresponding 931 /// capture group `name`, and writes them to the `dst` buffer given. 932 /// 933 /// `name` may be an integer corresponding to the index of the 934 /// capture group (counted by order of opening parenthesis where `0` is the 935 /// entire match) or it can be a name (consisting of letters, digits or 936 /// underscores) corresponding to a named capture group. 937 /// 938 /// If `name` isn't a valid capture group (whether the name doesn't exist 939 /// or isn't a valid index), then it is replaced with the empty string. 940 /// 941 /// The longest possible name is used. e.g., `$1a` looks up the capture 942 /// group named `1a` and not the capture group at index `1`. To exert more 943 /// precise control over the name, use braces, e.g., `${1}a`. 944 /// 945 /// To write a literal `$` use `$$`. expand(&self, replacement: &[u8], dst: &mut Vec<u8>)946 pub fn expand(&self, replacement: &[u8], dst: &mut Vec<u8>) { 947 expand_bytes(self, replacement, dst) 948 } 949 950 /// Returns the number of captured groups. 951 /// 952 /// This is always at least `1`, since every regex has at least one capture 953 /// group that corresponds to the full match. 954 #[inline] len(&self) -> usize955 pub fn len(&self) -> usize { 956 self.locs.len() 957 } 958 } 959 960 impl<'t> fmt::Debug for Captures<'t> { fmt(&self, f: &mut fmt::Formatter) -> fmt::Result961 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { 962 f.debug_tuple("Captures").field(&CapturesDebug(self)).finish() 963 } 964 } 965 966 struct CapturesDebug<'c, 't: 'c>(&'c Captures<'t>); 967 968 impl<'c, 't> fmt::Debug for CapturesDebug<'c, 't> { fmt(&self, f: &mut fmt::Formatter) -> fmt::Result969 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { 970 fn escape_bytes(bytes: &[u8]) -> String { 971 let mut s = String::new(); 972 for &b in bytes { 973 s.push_str(&escape_byte(b)); 974 } 975 s 976 } 977 978 fn escape_byte(byte: u8) -> String { 979 use std::ascii::escape_default; 980 981 let escaped: Vec<u8> = escape_default(byte).collect(); 982 String::from_utf8_lossy(&escaped).into_owned() 983 } 984 985 // We'd like to show something nice here, even if it means an 986 // allocation to build a reverse index. 987 let slot_to_name: HashMap<&usize, &String> = 988 self.0.named_groups.iter().map(|(a, b)| (b, a)).collect(); 989 let mut map = f.debug_map(); 990 for (slot, m) in self.0.locs.iter().enumerate() { 991 let m = m.map(|(s, e)| escape_bytes(&self.0.text[s..e])); 992 if let Some(name) = slot_to_name.get(&slot) { 993 map.entry(&name, &m); 994 } else { 995 map.entry(&slot, &m); 996 } 997 } 998 map.finish() 999 } 1000 } 1001 1002 /// Get a group by index. 1003 /// 1004 /// `'t` is the lifetime of the matched text. 1005 /// 1006 /// The text can't outlive the `Captures` object if this method is 1007 /// used, because of how `Index` is defined (normally `a[i]` is part 1008 /// of `a` and can't outlive it); to do that, use `get()` instead. 1009 /// 1010 /// # Panics 1011 /// 1012 /// If there is no group at the given index. 1013 impl<'t> Index<usize> for Captures<'t> { 1014 type Output = [u8]; 1015 index(&self, i: usize) -> &[u8]1016 fn index(&self, i: usize) -> &[u8] { 1017 self.get(i) 1018 .map(|m| m.as_bytes()) 1019 .unwrap_or_else(|| panic!("no group at index '{}'", i)) 1020 } 1021 } 1022 1023 /// Get a group by name. 1024 /// 1025 /// `'t` is the lifetime of the matched text and `'i` is the lifetime 1026 /// of the group name (the index). 1027 /// 1028 /// The text can't outlive the `Captures` object if this method is 1029 /// used, because of how `Index` is defined (normally `a[i]` is part 1030 /// of `a` and can't outlive it); to do that, use `name` instead. 1031 /// 1032 /// # Panics 1033 /// 1034 /// If there is no group named by the given value. 1035 impl<'t, 'i> Index<&'i str> for Captures<'t> { 1036 type Output = [u8]; 1037 index<'a>(&'a self, name: &'i str) -> &'a [u8]1038 fn index<'a>(&'a self, name: &'i str) -> &'a [u8] { 1039 self.name(name) 1040 .map(|m| m.as_bytes()) 1041 .unwrap_or_else(|| panic!("no group named '{}'", name)) 1042 } 1043 } 1044 1045 /// An iterator that yields all capturing matches in the order in which they 1046 /// appear in the regex. 1047 /// 1048 /// If a particular capture group didn't participate in the match, then `None` 1049 /// is yielded for that capture. The first match always corresponds to the 1050 /// overall match of the regex. 1051 /// 1052 /// The lifetime `'c` corresponds to the lifetime of the `Captures` value, and 1053 /// the lifetime `'t` corresponds to the originally matched text. 1054 pub struct SubCaptureMatches<'c, 't: 'c> { 1055 caps: &'c Captures<'t>, 1056 it: SubCapturesPosIter<'c>, 1057 } 1058 1059 impl<'c, 't> Iterator for SubCaptureMatches<'c, 't> { 1060 type Item = Option<Match<'t>>; 1061 next(&mut self) -> Option<Option<Match<'t>>>1062 fn next(&mut self) -> Option<Option<Match<'t>>> { 1063 self.it 1064 .next() 1065 .map(|cap| cap.map(|(s, e)| Match::new(self.caps.text, s, e))) 1066 } 1067 } 1068 1069 /// Replacer describes types that can be used to replace matches in a byte 1070 /// string. 1071 /// 1072 /// In general, users of this crate shouldn't need to implement this trait, 1073 /// since implementations are already provided for `&[u8]` and 1074 /// `FnMut(&Captures) -> Vec<u8>` (or any `FnMut(&Captures) -> T` 1075 /// where `T: AsRef<[u8]>`), which covers most use cases. 1076 pub trait Replacer { 1077 /// Appends text to `dst` to replace the current match. 1078 /// 1079 /// The current match is represented by `caps`, which is guaranteed to 1080 /// have a match at capture group `0`. 1081 /// 1082 /// For example, a no-op replacement would be 1083 /// `dst.extend(&caps[0])`. replace_append(&mut self, caps: &Captures, dst: &mut Vec<u8>)1084 fn replace_append(&mut self, caps: &Captures, dst: &mut Vec<u8>); 1085 1086 /// Return a fixed unchanging replacement byte string. 1087 /// 1088 /// When doing replacements, if access to `Captures` is not needed (e.g., 1089 /// the replacement byte string does not need `$` expansion), then it can 1090 /// be beneficial to avoid finding sub-captures. 1091 /// 1092 /// In general, this is called once for every call to `replacen`. no_expansion<'r>(&'r mut self) -> Option<Cow<'r, [u8]>>1093 fn no_expansion<'r>(&'r mut self) -> Option<Cow<'r, [u8]>> { 1094 None 1095 } 1096 1097 /// Return a `Replacer` that borrows and wraps this `Replacer`. 1098 /// 1099 /// This is useful when you want to take a generic `Replacer` (which might 1100 /// not be cloneable) and use it without consuming it, so it can be used 1101 /// more than once. 1102 /// 1103 /// # Example 1104 /// 1105 /// ``` 1106 /// use regex::bytes::{Regex, Replacer}; 1107 /// 1108 /// fn replace_all_twice<R: Replacer>( 1109 /// re: Regex, 1110 /// src: &[u8], 1111 /// mut rep: R, 1112 /// ) -> Vec<u8> { 1113 /// let dst = re.replace_all(src, rep.by_ref()); 1114 /// let dst = re.replace_all(&dst, rep.by_ref()); 1115 /// dst.into_owned() 1116 /// } 1117 /// ``` by_ref<'r>(&'r mut self) -> ReplacerRef<'r, Self>1118 fn by_ref<'r>(&'r mut self) -> ReplacerRef<'r, Self> { 1119 ReplacerRef(self) 1120 } 1121 } 1122 1123 /// By-reference adaptor for a `Replacer` 1124 /// 1125 /// Returned by [`Replacer::by_ref`](trait.Replacer.html#method.by_ref). 1126 #[derive(Debug)] 1127 pub struct ReplacerRef<'a, R: ?Sized + 'a>(&'a mut R); 1128 1129 impl<'a, R: Replacer + ?Sized + 'a> Replacer for ReplacerRef<'a, R> { replace_append(&mut self, caps: &Captures, dst: &mut Vec<u8>)1130 fn replace_append(&mut self, caps: &Captures, dst: &mut Vec<u8>) { 1131 self.0.replace_append(caps, dst) 1132 } no_expansion<'r>(&'r mut self) -> Option<Cow<'r, [u8]>>1133 fn no_expansion<'r>(&'r mut self) -> Option<Cow<'r, [u8]>> { 1134 self.0.no_expansion() 1135 } 1136 } 1137 1138 impl<'a> Replacer for &'a [u8] { replace_append(&mut self, caps: &Captures, dst: &mut Vec<u8>)1139 fn replace_append(&mut self, caps: &Captures, dst: &mut Vec<u8>) { 1140 caps.expand(*self, dst); 1141 } 1142 no_expansion(&mut self) -> Option<Cow<[u8]>>1143 fn no_expansion(&mut self) -> Option<Cow<[u8]>> { 1144 match find_byte(b'$', *self) { 1145 Some(_) => None, 1146 None => Some(Cow::Borrowed(*self)), 1147 } 1148 } 1149 } 1150 1151 impl<F, T> Replacer for F 1152 where 1153 F: FnMut(&Captures) -> T, 1154 T: AsRef<[u8]>, 1155 { replace_append(&mut self, caps: &Captures, dst: &mut Vec<u8>)1156 fn replace_append(&mut self, caps: &Captures, dst: &mut Vec<u8>) { 1157 dst.extend_from_slice((*self)(caps).as_ref()); 1158 } 1159 } 1160 1161 /// `NoExpand` indicates literal byte string replacement. 1162 /// 1163 /// It can be used with `replace` and `replace_all` to do a literal byte string 1164 /// replacement without expanding `$name` to their corresponding capture 1165 /// groups. This can be both convenient (to avoid escaping `$`, for example) 1166 /// and performant (since capture groups don't need to be found). 1167 /// 1168 /// `'t` is the lifetime of the literal text. 1169 pub struct NoExpand<'t>(pub &'t [u8]); 1170 1171 impl<'t> Replacer for NoExpand<'t> { replace_append(&mut self, _: &Captures, dst: &mut Vec<u8>)1172 fn replace_append(&mut self, _: &Captures, dst: &mut Vec<u8>) { 1173 dst.extend_from_slice(self.0); 1174 } 1175 no_expansion(&mut self) -> Option<Cow<[u8]>>1176 fn no_expansion(&mut self) -> Option<Cow<[u8]>> { 1177 Some(Cow::Borrowed(self.0)) 1178 } 1179 } 1180