11.1.6 (2019-04-16)
2==================
3This release fixes a regression introduced by a bug fix (for
4[BUG #557](https://github.com/rust-lang/regex/issues/557)) which could cause
5the regex engine to enter an infinite loop. This bug was originally
6[reported against ripgrep](https://github.com/BurntSushi/ripgrep/issues/1247).
7
8
91.1.5 (2019-04-01)
10==================
11This release fixes a bug in regex's dependency specification where it requires
12a newer version of regex-syntax, but this wasn't communicated correctly in the
13Cargo.toml. This would have been caught by a minimal version check, but this
14check was disabled because the `rand` crate itself advertises incorrect
15dependency specifications.
16
17Bug fixes:
18
19* [BUG #570](https://github.com/rust-lang/regex/pull/570):
20  Fix regex-syntax minimal version.
21
22
231.1.4 (2019-03-31)
24==================
25This release fixes a backwards compatibility regression where Regex was no
26longer UnwindSafe. This was caused by the upgrade to aho-corasick 0.7, whose
27AhoCorasick type was itself not UnwindSafe. This has been fixed in aho-corasick
280.7.4, which we now require.
29
30Bug fixes:
31
32* [BUG #568](https://github.com/rust-lang/regex/pull/568):
33  Fix an API regression where Regex was no longer UnwindSafe.
34
35
361.1.3 (2019-03-30)
37==================
38This releases fixes a few bugs and adds a performance improvement when a regex
39is a simple alternation of literals.
40
41Performance improvements:
42
43* [OPT #566](https://github.com/rust-lang/regex/pull/566):
44  Upgrades `aho-corasick` to 0.7 and uses it for `foo|bar|...|quux` regexes.
45
46Bug fixes:
47
48* [BUG #527](https://github.com/rust-lang/regex/issues/527):
49  Fix a bug where the parser would panic on patterns like `((?x))`.
50* [BUG #555](https://github.com/rust-lang/regex/issues/555):
51  Fix a bug where the parser would panic on patterns like `(?m){1,1}`.
52* [BUG #557](https://github.com/rust-lang/regex/issues/557):
53  Fix a bug where captures could lead to an incorrect match.
54
55
561.1.2 (2019-02-27)
57==================
58This release fixes a bug found in the fix introduced in 1.1.1.
59
60Bug fixes:
61
62* [BUG edf45e6f](https://github.com/rust-lang/regex/commit/edf45e6f):
63  Fix bug introduced in reverse suffix literal matcher in the 1.1.1 release.
64
65
661.1.1 (2019-02-27)
67==================
68This is a small release with one fix for a bug caused by literal optimizations.
69
70Bug fixes:
71
72* [BUG 661bf53d](https://github.com/rust-lang/regex/commit/661bf53d):
73  Fixes a bug in the reverse suffix literal optimization. This was originally
74  reported
75  [against ripgrep](https://github.com/BurntSushi/ripgrep/issues/1203).
76
77
781.1.0 (2018-11-30)
79==================
80This is a small release with a couple small enhancements. This release also
81increases the minimal supported Rust version (MSRV) to 1.24.1 (from 1.20.0). In
82accordance with this crate's MSRV policy, this release bumps the minor version
83number.
84
85Performance improvements:
86
87* [OPT #511](https://github.com/rust-lang/regex/pull/511),
88  [OPT #540](https://github.com/rust-lang/regex/pull/540):
89  Improve lazy DFA construction for large regex sets.
90
91New features:
92
93* [FEATURE #538](https://github.com/rust-lang/regex/pull/538):
94  Add Emoji and "break" Unicode properties. See [UNICODE.md](UNICODE.md).
95
96Bug fixes:
97
98* [BUG #530](https://github.com/rust-lang/regex/pull/530):
99  Add Unicode license (for data tables).
100* Various typo/doc fixups.
101
102
1031.0.6 (2018-11-06)
104==================
105This is a small release.
106
107Performance improvements:
108
109* [OPT #513](https://github.com/rust-lang/regex/pull/513):
110  Improve performance of compiling large Unicode classes by 8-10%.
111
112Bug fixes:
113
114* [BUG #533](https://github.com/rust-lang/regex/issues/533):
115  Fix definition of `[[:blank:]]` class that regressed in `regex-syntax 0.5`.
116
117
1181.0.5 (2018-09-06)
119==================
120This is a small release with an API enhancement.
121
122New features:
123
124* [FEATURE #509](https://github.com/rust-lang/regex/pull/509):
125  Generalize impls of the `Replacer` trait.
126
127
1281.0.4 (2018-08-25)
129==================
130This is a small release that bumps the quickcheck dependency.
131
132
1331.0.3 (2018-08-24)
134==================
135This is a small bug fix release.
136
137Bug fixes:
138
139* [BUG #504](https://github.com/rust-lang/regex/pull/504):
140  Fix for Cargo's "minimal version" support.
141* [BUG 1e39165f](https://github.com/rust-lang/regex/commit/1e39165f):
142  Fix doc examples for byte regexes.
143
144
1451.0.2 (2018-07-18)
146==================
147This release exposes some new lower level APIs on `Regex` that permit
148amortizing allocation and controlling the location at which a search is
149performed in a more granular way. Most users of the regex crate will not
150need or want to use these APIs.
151
152New features:
153
154* [FEATURE #493](https://github.com/rust-lang/regex/pull/493):
155  Add a few lower level APIs for amortizing allocation and more fine grained
156  searching.
157
158Bug fixes:
159
160* [BUG 3981d2ad](https://github.com/rust-lang/regex/commit/3981d2ad):
161  Correct outdated documentation on `RegexBuilder::dot_matches_new_line`.
162* [BUG 7ebe4ae0](https://github.com/rust-lang/regex/commit/7ebe4ae0):
163  Correct outdated documentation on `Parser::allow_invalid_utf8` in the
164  `regex-syntax` crate.
165* [BUG 24c7770b](https://github.com/rust-lang/regex/commit/24c7770b):
166  Fix a bug in the HIR printer where it wouldn't correctly escape meta
167  characters in character classes.
168
169
1701.0.1 (2018-06-19)
171==================
172This release upgrades regex's Unicode tables to Unicode 11, and enables SIMD
173optimizations automatically on Rust stable (1.27 or newer).
174
175New features:
176
177* [FEATURE #486](https://github.com/rust-lang/regex/pull/486):
178  Implement `size_hint` on `RegexSet` match iterators.
179* [FEATURE #488](https://github.com/rust-lang/regex/pull/488):
180  Update Unicode tables for Unicode 11.
181* [FEATURE #490](https://github.com/rust-lang/regex/pull/490):
182  SIMD optimizations are now enabled automatically in Rust stable, for versions
183  1.27 and up. No compilation flags or features need to be set. CPU support
184  SIMD is detected automatically at runtime.
185
186Bug fixes:
187
188* [BUG #482](https://github.com/rust-lang/regex/pull/482):
189  Present a better compilation error when the `use_std` feature isn't used.
190
191
1921.0.0 (2018-05-01)
193==================
194This release marks the 1.0 release of regex.
195
196While this release includes some breaking changes, most users of older versions
197of the regex library should be able to migrate to 1.0 by simply bumping the
198version number. The important changes are as follows:
199
200* We adopt Rust 1.20 as the new minimum supported version of Rust for regex.
201  We also tentativley adopt a policy that permits bumping the minimum supported
202  version of Rust in minor version releases of regex, but no patch releases.
203  That is, with respect to semver, we do not strictly consider bumping the
204  minimum version of Rust to be a breaking change, but adopt a conservative
205  stance as a compromise.
206* Octal syntax in regular expressions has been disabled by default. This
207  permits better error messages that inform users that backreferences aren't
208  available. Octal syntax can be re-enabled via the corresponding option on
209  `RegexBuilder`.
210* `(?-u:\B)` is no longer allowed in Unicode regexes since it can match at
211  invalid UTF-8 code unit boundaries. `(?-u:\b)` is still allowed in Unicode
212  regexes.
213* The `From<regex_syntax::Error>` impl has been removed. This formally removes
214  the public dependency on `regex-syntax`.
215* A new feature, `use_std`, has been added and enabled by default. Disabling
216  the feature will result in a compilation error. In the future, this may
217  permit us to support `no_std` environments (w/ `alloc`) in a backwards
218  compatible way.
219
220For more information and discussion, please see
221[1.0 release tracking issue](https://github.com/rust-lang/regex/issues/457).
222
223
2240.2.11 (2018-05-01)
225===================
226This release primarily contains bug fixes. Some of them resolve bugs where
227the parser could panic.
228
229New features:
230
231* [FEATURE #459](https://github.com/rust-lang/regex/pull/459):
232  Include C++'s standard regex library and Boost's regex library in the
233  benchmark harness. We now include D/libphobos, C++/std, C++/boost, Oniguruma,
234  PCRE1, PCRE2, RE2 and Tcl in the harness.
235
236Bug fixes:
237
238* [BUG #445](https://github.com/rust-lang/regex/issues/445):
239  Clarify order of indices returned by RegexSet match iterator.
240* [BUG #461](https://github.com/rust-lang/regex/issues/461):
241  Improve error messages for invalid regexes like `[\d-a]`.
242* [BUG #464](https://github.com/rust-lang/regex/issues/464):
243  Fix a bug in the error message pretty printer that could cause a panic when
244  a regex contained a literal `\n` character.
245* [BUG #465](https://github.com/rust-lang/regex/issues/465):
246  Fix a panic in the parser that was caused by applying a repetition operator
247  to `(?flags)`.
248* [BUG #466](https://github.com/rust-lang/regex/issues/466):
249  Fix a bug where `\pC` was not recognized as an alias for `\p{Other}`.
250* [BUG #470](https://github.com/rust-lang/regex/pull/470):
251  Fix a bug where literal searches did more work than necessary for anchored
252  regexes.
253
254
2550.2.10 (2018-03-16)
256===================
257This release primarily updates the regex crate to changes made in `std::arch`
258on nightly Rust.
259
260New features:
261
262* [FEATURE #458](https://github.com/rust-lang/regex/pull/458):
263  The `Hir` type in `regex-syntax` now has a printer.
264
265
2660.2.9 (2018-03-12)
267==================
268This release introduces a new nightly only feature, `unstable`, which enables
269SIMD optimizations for certain types of regexes. No additional compile time
270options are necessary, and the regex crate will automatically choose the
271best CPU features at run time. As a result, the `simd` (nightly only) crate
272dependency has been dropped.
273
274New features:
275
276* [FEATURE #456](https://github.com/rust-lang/regex/pull/456):
277  The regex crate now includes AVX2 optimizations in addition to the extant
278  SSSE3 optimization.
279
280Bug fixes:
281
282* [BUG #455](https://github.com/rust-lang/regex/pull/455):
283  Fix a bug where `(?x)[ / - ]` failed to parse.
284
285
2860.2.8 (2018-03-12)
287==================
288Bug gixes:
289
290* [BUG #454](https://github.com/rust-lang/regex/pull/454):
291  Fix a bug in the nest limit checker being too aggressive.
292
293
2940.2.7 (2018-03-07)
295==================
296This release includes a ground-up rewrite of the regex-syntax crate, which has
297been in development for over a year.
298
299New features:
300
301* Error messages for invalid regexes have been greatly improved. You get these
302  automatically; you don't need to do anything. In addition to better
303  formatting, error messages will now explicitly call out the use of look
304  around. When regex 1.0 is released, this will happen for backreferences as
305  well.
306* Full support for intersection, difference and symmetric difference of
307  character classes. These can be used via the `&&`, `--` and `~~` binary
308  operators within classes.
309* A Unicode Level 1 conformat implementation of `\p{..}` character classes.
310  Things like `\p{scx:Hira}`, `\p{age:3.2}` or `\p{Changes_When_Casefolded}`
311  now work. All property name and value aliases are supported, and properties
312  are selected via loose matching. e.g., `\p{Greek}` is the same as
313  `\p{G r E e K}`.
314* A new `UNICODE.md` document has been added to this repository that
315  exhaustively documents support for UTS#18.
316* Empty sub-expressions are now permitted in most places. That is, `()+` is
317  now a valid regex.
318* Almost everything in regex-syntax now uses constant stack space, even when
319  performing anaylsis that requires structural induction. This reduces the risk
320  of a user provided regular expression causing a stack overflow.
321* [FEATURE #174](https://github.com/rust-lang/regex/issues/174):
322  The `Ast` type in `regex-syntax` now contains span information.
323* [FEATURE #424](https://github.com/rust-lang/regex/issues/424):
324  Support `\u`, `\u{...}`, `\U` and `\U{...}` syntax for specifying code points
325  in a regular expression.
326* [FEATURE #449](https://github.com/rust-lang/regex/pull/449):
327  Add a `Replace::by_ref` adapter for use of a replacer without consuming it.
328
329Bug fixes:
330
331* [BUG #446](https://github.com/rust-lang/regex/issues/446):
332  We re-enable the Boyer-Moore literal matcher.
333
334
3350.2.6 (2018-02-08)
336==================
337Bug fixes:
338
339* [BUG #446](https://github.com/rust-lang/regex/issues/446):
340  Fixes a bug in the new Boyer-Moore searcher that results in a match failure.
341  We fix this bug by temporarily disabling Boyer-Moore.
342
343
3440.2.5 (2017-12-30)
345==================
346Bug fixes:
347
348* [BUG #437](https://github.com/rust-lang/regex/issues/437):
349  Fixes a bug in the new Boyer-Moore searcher that results in a panic.
350
351
3520.2.4 (2017-12-30)
353==================
354New features:
355
356* [FEATURE #348](https://github.com/rust-lang/regex/pull/348):
357  Improve performance for capture searches on anchored regex.
358  (Contributed by @ethanpailes. Nice work!)
359* [FEATURE #419](https://github.com/rust-lang/regex/pull/419):
360  Expand literal searching to include Tuned Boyer-Moore in some cases.
361  (Contributed by @ethanpailes. Nice work!)
362
363Bug fixes:
364
365* [BUG](https://github.com/rust-lang/regex/pull/436):
366  The regex compiler plugin has been removed.
367* [BUG](https://github.com/rust-lang/regex/pull/436):
368  `simd` has been bumped to `0.2.1`, which fixes a Rust nightly build error.
369* [BUG](https://github.com/rust-lang/regex/pull/436):
370  Bring the benchmark harness up to date.
371
372
3730.2.3 (2017-11-30)
374==================
375New features:
376
377* [FEATURE #374](https://github.com/rust-lang/regex/pull/374):
378  Add `impl From<Match> for &str`.
379* [FEATURE #380](https://github.com/rust-lang/regex/pull/380):
380  Derive `Clone` and `PartialEq` on `Error`.
381* [FEATURE #400](https://github.com/rust-lang/regex/pull/400):
382  Update to Unicode 10.
383
384Bug fixes:
385
386* [BUG #375](https://github.com/rust-lang/regex/issues/375):
387  Fix a bug that prevented the bounded backtracker from terminating.
388* [BUG #393](https://github.com/rust-lang/regex/issues/393),
389  [BUG #394](https://github.com/rust-lang/regex/issues/394):
390  Fix bug with `replace` methods for empty matches.
391
392
3930.2.2 (2017-05-21)
394==================
395New features:
396
397* [FEATURE #341](https://github.com/rust-lang/regex/issues/341):
398  Support nested character classes and intersection operation.
399  For example, `[\p{Greek}&&\pL]` matches greek letters and
400  `[[0-9]&&[^4]]` matches every decimal digit except `4`.
401  (Much thanks to @robinst, who contributed this awesome feature.)
402
403Bug fixes:
404
405* [BUG #321](https://github.com/rust-lang/regex/issues/321):
406  Fix bug in literal extraction and UTF-8 decoding.
407* [BUG #326](https://github.com/rust-lang/regex/issues/326):
408  Add documentation tip about the `(?x)` flag.
409* [BUG #333](https://github.com/rust-lang/regex/issues/333):
410  Show additional replacement example using curly braces.
411* [BUG #334](https://github.com/rust-lang/regex/issues/334):
412  Fix bug when resolving captures after a match.
413* [BUG #338](https://github.com/rust-lang/regex/issues/338):
414  Add example that uses `Captures::get` to API documentation.
415* [BUG #353](https://github.com/rust-lang/regex/issues/353):
416  Fix RegexSet bug that caused match failure in some cases.
417* [BUG #354](https://github.com/rust-lang/regex/pull/354):
418  Fix panic in parser when `(?x)` is used.
419* [BUG #358](https://github.com/rust-lang/regex/issues/358):
420  Fix literal optimization bug with RegexSet.
421* [BUG #359](https://github.com/rust-lang/regex/issues/359):
422  Fix example code in README.
423* [BUG #365](https://github.com/rust-lang/regex/pull/365):
424  Fix bug in `rure_captures_len` in the C binding.
425* [BUG #367](https://github.com/rust-lang/regex/issues/367):
426  Fix byte class bug that caused a panic.
427
428
4290.2.1
430=====
431One major bug with `replace_all` has been fixed along with a couple of other
432touchups.
433
434* [BUG #312](https://github.com/rust-lang/regex/issues/312):
435  Fix documentation for `NoExpand` to reference correct lifetime parameter.
436* [BUG #314](https://github.com/rust-lang/regex/issues/314):
437  Fix a bug with `replace_all` when replacing a match with the empty string.
438* [BUG #316](https://github.com/rust-lang/regex/issues/316):
439  Note a missing breaking change from the `0.2.0` CHANGELOG entry.
440  (`RegexBuilder::compile` was renamed to `RegexBuilder::build`.)
441* [BUG #324](https://github.com/rust-lang/regex/issues/324):
442  Compiling `regex` should only require one version of `memchr` crate.
443
444
4450.2.0
446=====
447This is a new major release of the regex crate, and is an implementation of the
448[regex 1.0 RFC](https://github.com/rust-lang/rfcs/blob/master/text/1620-regex-1.0.md).
449We are releasing a `0.2` first, and if there are no major problems, we will
450release a `1.0` shortly. For `0.2`, the minimum *supported* Rust version is
4511.12.
452
453There are a number of **breaking changes** in `0.2`. They are split into two
454types. The first type correspond to breaking changes in regular expression
455syntax. The second type correspond to breaking changes in the API.
456
457Breaking changes for regex syntax:
458
459* POSIX character classes now require double bracketing. Previously, the regex
460  `[:upper:]` would parse as the `upper` POSIX character class. Now it parses
461  as the character class containing the characters `:upper:`. The fix to this
462  change is to use `[[:upper:]]` instead. Note that variants like
463  `[[:upper:][:blank:]]` continue to work.
464* The character `[` must always be escaped inside a character class.
465* The characters `&`, `-` and `~` must be escaped if any one of them are
466  repeated consecutively. For example, `[&]`, `[\&]`, `[\&\&]`, `[&-&]` are all
467  equivalent while `[&&]` is illegal. (The motivation for this and the prior
468  change is to provide a backwards compatible path for adding character class
469  set notation.)
470* A `bytes::Regex` now has Unicode mode enabled by default (like the main
471  `Regex` type). This means regexes compiled with `bytes::Regex::new` that
472  don't have the Unicode flag set should add `(?-u)` to recover the original
473  behavior.
474
475Breaking changes for the regex API:
476
477* `find` and `find_iter` now **return `Match` values instead of
478  `(usize, usize)`.** `Match` values have `start` and `end` methods, which
479  return the match offsets. `Match` values also have an `as_str` method,
480  which returns the text of the match itself.
481* The `Captures` type now only provides a single iterator over all capturing
482  matches, which should replace uses of `iter` and `iter_pos`. Uses of
483  `iter_named` should use the `capture_names` method on `Regex`.
484* The `at` method on the `Captures` type has been renamed to `get`, and it
485  now returns a `Match`. Similarly, the `name` method on `Captures` now returns
486  a `Match`.
487* The `replace` methods now return `Cow` values. The `Cow::Borrowed` variant
488  is returned when no replacements are made.
489* The `Replacer` trait has been completely overhauled. This should only
490  impact clients that implement this trait explicitly. Standard uses of
491  the `replace` methods should continue to work unchanged. If you implement
492  the `Replacer` trait, please consult the new documentation.
493* The `quote` free function has been renamed to `escape`.
494* The `Regex::with_size_limit` method has been removed. It is replaced by
495  `RegexBuilder::size_limit`.
496* The `RegexBuilder` type has switched from owned `self` method receivers to
497  `&mut self` method receivers. Most uses will continue to work unchanged, but
498  some code may require naming an intermediate variable to hold the builder.
499* The `compile` method on `RegexBuilder` has been renamed to `build`.
500* The free `is_match` function has been removed. It is replaced by compiling
501  a `Regex` and calling its `is_match` method.
502* The `PartialEq` and `Eq` impls on `Regex` have been dropped. If you relied
503  on these impls, the fix is to define a wrapper type around `Regex`, impl
504  `Deref` on it and provide the necessary impls.
505* The `is_empty` method on `Captures` has been removed. This always returns
506  `false`, so its use is superfluous.
507* The `Syntax` variant of the `Error` type now contains a string instead of
508  a `regex_syntax::Error`. If you were examining syntax errors more closely,
509  you'll need to explicitly use the `regex_syntax` crate to re-parse the regex.
510* The `InvalidSet` variant of the `Error` type has been removed since it is
511  no longer used.
512* Most of the iterator types have been renamed to match conventions. If you
513  were using these iterator types explicitly, please consult the documentation
514  for its new name. For example, `RegexSplits` has been renamed to `Split`.
515
516A number of bugs have been fixed:
517
518* [BUG #151](https://github.com/rust-lang/regex/issues/151):
519  The `Replacer` trait has been changed to permit the caller to control
520  allocation.
521* [BUG #165](https://github.com/rust-lang/regex/issues/165):
522  Remove the free `is_match` function.
523* [BUG #166](https://github.com/rust-lang/regex/issues/166):
524  Expose more knobs (available in `0.1`) and remove `with_size_limit`.
525* [BUG #168](https://github.com/rust-lang/regex/issues/168):
526  Iterators produced by `Captures` now have the correct lifetime parameters.
527* [BUG #175](https://github.com/rust-lang/regex/issues/175):
528  Fix a corner case in the parsing of POSIX character classes.
529* [BUG #178](https://github.com/rust-lang/regex/issues/178):
530  Drop the `PartialEq` and `Eq` impls on `Regex`.
531* [BUG #179](https://github.com/rust-lang/regex/issues/179):
532  Remove `is_empty` from `Captures` since it always returns false.
533* [BUG #276](https://github.com/rust-lang/regex/issues/276):
534  Position of named capture can now be retrieved from a `Captures`.
535* [BUG #296](https://github.com/rust-lang/regex/issues/296):
536  Remove winapi/kernel32-sys dependency on UNIX.
537* [BUG #307](https://github.com/rust-lang/regex/issues/307):
538  Fix error on emscripten.
539
540
5410.1.80
542======
543* [PR #292](https://github.com/rust-lang/regex/pull/292):
544  Fixes bug #291, which was introduced by PR #290.
545
5460.1.79
547======
548* Require regex-syntax 0.3.8.
549
5500.1.78
551======
552* [PR #290](https://github.com/rust-lang/regex/pull/290):
553  Fixes bug #289, which caused some regexes with a certain combination
554  of literals to match incorrectly.
555
5560.1.77
557======
558* [PR #281](https://github.com/rust-lang/regex/pull/281):
559  Fixes bug #280 by disabling all literal optimizations when a pattern
560  is partially anchored.
561
5620.1.76
563======
564* Tweak criteria for using the Teddy literal matcher.
565
5660.1.75
567======
568* [PR #275](https://github.com/rust-lang/regex/pull/275):
569  Improves match verification performance in the Teddy SIMD searcher.
570* [PR #278](https://github.com/rust-lang/regex/pull/278):
571  Replaces slow substring loop in the Teddy SIMD searcher with Aho-Corasick.
572* Implemented DoubleEndedIterator on regex set match iterators.
573
5740.1.74
575======
576* Release regex-syntax 0.3.5 with a minor bug fix.
577* Fix bug #272.
578* Fix bug #277.
579* [PR #270](https://github.com/rust-lang/regex/pull/270):
580  Fixes bugs #264, #268 and an unreported where the DFA cache size could be
581  drastically under estimated in some cases (leading to high unexpected memory
582  usage).
583
5840.1.73
585======
586* Release `regex-syntax 0.3.4`.
587* Bump `regex-syntax` dependency version for `regex` to `0.3.4`.
588
5890.1.72
590======
591* [PR #262](https://github.com/rust-lang/regex/pull/262):
592  Fixes a number of small bugs caught by fuzz testing (AFL).
593
5940.1.71
595======
596* [PR #236](https://github.com/rust-lang/regex/pull/236):
597  Fix a bug in how suffix literals were extracted, which could lead
598  to invalid match behavior in some cases.
599
6000.1.70
601======
602* [PR #231](https://github.com/rust-lang/regex/pull/231):
603  Add SIMD accelerated multiple pattern search.
604* [PR #228](https://github.com/rust-lang/regex/pull/228):
605  Reintroduce the reverse suffix literal optimization.
606* [PR #226](https://github.com/rust-lang/regex/pull/226):
607  Implements NFA state compression in the lazy DFA.
608* [PR #223](https://github.com/rust-lang/regex/pull/223):
609  A fully anchored RegexSet can now short-circuit.
610
6110.1.69
612======
613* [PR #216](https://github.com/rust-lang/regex/pull/216):
614  Tweak the threshold for running backtracking.
615* [PR #217](https://github.com/rust-lang/regex/pull/217):
616  Add upper limit (from the DFA) to capture search (for the NFA).
617* [PR #218](https://github.com/rust-lang/regex/pull/218):
618  Add rure, a C API.
619
6200.1.68
621======
622* [PR #210](https://github.com/rust-lang/regex/pull/210):
623  Fixed a performance bug in `bytes::Regex::replace` where `extend` was used
624  instead of `extend_from_slice`.
625* [PR #211](https://github.com/rust-lang/regex/pull/211):
626  Fixed a bug in the handling of word boundaries in the DFA.
627* [PR #213](https://github.com/rust-lang/pull/213):
628  Added RE2 and Tcl to the benchmark harness. Also added a CLI utility from
629  running regexes using any of the following regex engines: PCRE1, PCRE2,
630  Oniguruma, RE2, Tcl and of course Rust's own regexes.
631
6320.1.67
633======
634* [PR #201](https://github.com/rust-lang/regex/pull/201):
635  Fix undefined behavior in the `regex!` compiler plugin macro.
636* [PR #205](https://github.com/rust-lang/regex/pull/205):
637  More improvements to DFA performance. Competitive with RE2. See PR for
638  benchmarks.
639* [PR #209](https://github.com/rust-lang/regex/pull/209):
640  Release 0.1.66 was semver incompatible since it required a newer version
641  of Rust than previous releases. This PR fixes that. (And `0.1.66` was
642  yanked.)
643
6440.1.66
645======
646* Speculative support for Unicode word boundaries was added to the DFA. This
647  should remove the last common case that disqualified use of the DFA.
648* An optimization that scanned for suffix literals and then matched the regular
649  expression in reverse was removed because it had worst case quadratic time
650  complexity. It was replaced with a more limited optimization where, given any
651  regex of the form `re$`, it will be matched in reverse from the end of the
652  haystack.
653* [PR #202](https://github.com/rust-lang/regex/pull/202):
654  The inner loop of the DFA was heavily optimized to improve cache locality
655  and reduce the overall number of instructions run on each iteration. This
656  represents the first use of `unsafe` in `regex` (to elide bounds checks).
657* [PR #200](https://github.com/rust-lang/regex/pull/200):
658  Use of the `mempool` crate (which used thread local storage) was replaced
659  with a faster version of a similar API in @Amanieu's `thread_local` crate.
660  It should reduce contention when using a regex from multiple threads
661  simultaneously.
662* PCRE2 JIT benchmarks were added. A benchmark comparison can be found
663  [here](https://gist.github.com/anonymous/14683c01993e91689f7206a18675901b).
664  (Includes a comparison with PCRE1's JIT and Oniguruma.)
665* A bug where word boundaries weren't being matched correctly in the DFA was
666  fixed. This only affected use of `bytes::Regex`.
667* [#160](https://github.com/rust-lang/regex/issues/160):
668  `Captures` now has a `Debug` impl.
669