Version: 2026.1.14

    Git issue 596: Specifying {e<=0} causes ca 210× slow-down.

    Added RISC-V wheels.

Version: 2025.11.3

    Git issue 594: Support relative PARNO in recursive subpatterns.

Version: 2025.10.23

    'setup.py' was missing from the source distribution.

Version: 2025.10.22

    Fixed test in main.yml.

Version: 2025.10.21

    Moved tests into subfolder.

Version: 2025.10.20

    Re-organised files.

    Updated to Unicode 17.0.0.

Version: 2025.9.20

    Enable free-threading support in cibuildwheel in another place.

Version: 2025.9.19

    Enable free-threading support in cibuildwheel.

Version: 2025.9.18

    Git issue 565: Support the free-threaded build of CPython 3.13

Version: 2025.9.1

    Git PR 585: Fix AttributeError: 'AnyAll' object has no attribute '_key'

Version: 2025.8.29

    Git issue 584: AttributeError: 'AnyAll' object has no attribute 'positive'

Version: 2025.7.34

    Git issue 575: Issues with ASCII/Unicode modifiers

Version: 2025.7.33

    Updated main.yml and pyproject.toml.

Version: 2025.7.32

    Git issue 580: Regression in v2025.7.31: \P{L} no longer matches in simple patterns

Version: 2025.7.31

    Further updates to main.yml.

Version: 2025.7.30

    Updated main.yml and pyproject.toml.

Version: 2025.7.29

    Git issue 572: Inline ASCII modifier doesn't seem to affect anything

Version: 2025.5.19

    Changed how main.yml skips unwanted Arch builds.

Version: 2025.5.18

    Updated main.yml to build Windows ARM64/aarch64 wheel.

    Updated licence text format in pyproject.toml.

Version: 2025.2.13

    Dropping support for Python 3.8 and removing it from main.yml.

Version: 2025.2.12

    Further fixes to main.yml.

Version: 2025.2.11

    Updated main.yml to Artifacts v4.

Version: 2025.2.10

    Git issue 551: Infinite loop on V1 search

    It's catastrophic backtracking due to the possibilities of full casefolding.

    Replacing `[\s\S]` with `(?s:.)` can help, but a proper fix would be more difficult.

Version: 2024.11.7

    Updated pyproject.toml and setup.py according to PEP 517.

Version: 2024.11.6

    Git issue 546: Partial match not working in some instances with non-greedy capture

Version: 2024.9.14

    Reverted to actions/download-artifact@v3 and actions/upload-artifact@v3 in main.yml because GitHub Actions failed when using them.

Version: 2024.9.13

    Updated to actions/upload-artifact@v4 in main.yml.

Version: 2024.9.12

    Updated to actions/download-artifact@v4 in main.yml.

Version: 2024.9.11

    Updated to Unicode 16.0.0.

Version: 2024.7.24

    Git issue 539: Bug: Partial matching fails on a simple example

Version: 2024.6.22

    Git issue 535: Regex fails Unicode 15.1 GraphemeBreakTest due to missing new GB9c rule implementation

Version: 2024.5.15

    Git issue 530: hangs with fuzzy and optionals

    It's not hanging, it'll finish eventually. It's just an example of catastrophic backtracking.

    The error printed when Ctrl+C is pressed does show a bug, though, which is now fixed.

Version: 2024.5.10

    Updated for Python 3.13.

    <time.h> now needs to be included explicitly because Python.h no longer includes it.

Version: 2024.4.28

    Git issue 527: `VERBOSE`/`X` flag breaks `\N` escapes

Version: 2024.4.16

    Git issue 525: segfault when fuzzy matching empty list

Version: 2023.12.25

    Cannot get release notification action in main.yml to work. Commenting it out for now.

Version: 2023.12.24

    Fixed invalid main.yml.

Version: 2023.12.23

    The escape function no longer escapes \x00. It's not necessary.

    Inline flags can now be turned off and apply to what follows.

    Added \R to match line endings.

Version: 2023.10.3

    Updated to Unicode 15.1.0.

Version: 2023.8.8

    Git issue 508: Regex doesn't build using CPython main (3.13.0a0)
    Removed usage of _PyBytes_Join and did a little tidying of the code that makes the result string.

Version: 2023.6.3

    Git issue 498: Conditional negative lookahead inside positive lookahead fails to match
    Conditional node needed an additional member that points to the true branch.

Version: 2023.5.5

    Removed semicolon after 'else' in 'munge_name'.

Version: 2023.5.4

    Fixed pyproject.toml and setup.py.

Version: 2023.5.3

    pyproject.toml was missing.

Version: 2023.5.2

    Added pyproject.toml.

Version: 2023.3.23

    Git issue 495: Running time for failing fullmatch increases rapidly with input length
    Re-enabled modified repeat guards due to regression in speed caused by excessive backtracking.

Version: 2023.3.22

    Git issue 494: Backtracking failure matching regex `^a?(a?)b?c\1$` against string `abca`
    Disabled repeat guards. They keep causing issues, and it's just simpler to rely on timeouts.

Version: 2022.10.31

    Updated text for supported Unicode and Python versions.

Version: 2022.9.13

    Updated to Unicode 15.0.0.

Version: 2022.9.11

    Updated version.

Version: 2022.8.17

    Git issue 477: \v for vertical spacing

    Added \p{HorizSpace} (\p{H}) and \p{VertSpace} (\p{V}).

Version: 2022.7.25

    Git issue 475: 2022.7.24 improperly released

    The file https://pypi.org/pypi/regex/2022.7.24/json was missing references to most of the wheels, so this is a new release in the hope that it was just a glitch in GitHub Actions.

Version: 2022.7.24

    Git issue 474: regex has no equivalent to re.Match.groups() for captures

    Added 'allcaptures' and 'allspans' methods to match objects.

    Fixed bug where compiling a pattern didn't always check for unused arguments.

Version: 2022.7.9

    Git issue 473: Emoji classified as letter

    The values for GC:Assigned and GC:LC were flipped.

Version: 2022.6.2

    Git issue 472: Revisit compilation flag to prevent adding a single explicitly compiled regex to the cache

    Added 'cache_pattern' parameter to 'compile' function to improve use of the cache.

Version: 2022.4.24

    Git issue 467: Scoped inline flags 'a', 'u' and 'L' affect global flags

    Those flags scan now be scoped.

Version: 2022.3.15

    Git issue 457: Difference with `re`, when repl returns None

    Make regex consistent with re by treating a replacement template of None as ''.

    Also, now rejects invalid ASCII escapes like re module does.

Version: 2022.3.2

    Git issue 453: Document last supported python2 version

    Added a brief reference to the last version to support Python 2 in README.rst.

    Git issue 456: RegexFlag exists in re, but not regex

    Updated the flags to use enum now that regex supports only Python 3.6+.

Version: 2022.1.21

    Added 'python_requires' to setup.py now that Python 2 no longer supported.

Version: 2022.1.18

    Updated version for new release.

Version: 2022.1.18

    * Dropped support for Python 2 and remove all references to Python <3.6, the earliest supported version.

    Removed Features.rst, which was just a duplicate of README.rst.

Version: 2021.11.9

    Git issue 443: 2021.11.9 source release is missing C headers

    Updated version.

Version: 2021.11.9

    Git issue 442: Fuzzy regex matching doesn't seem to test insertions correctly

Version: 2021.11.2

    Git issue 435: Unmatched groups: sub vs subf

    A similar fix also applies to expandf: unmatched groups should expand to an empty string.

Version: 2021.11.2

    Removed unused functions.

    Added long description type to setup.py.

Version: 2021.11.1

    Further changes for migration to Github.

Version: 2021.10.23

    Git issue 433: Disagreement between fuzzy_counts and fuzzy_changes

    Fuzzy changes were sometimes not removed when backtracking.

Version: 2021.10.21

    Removed Apple Silicon build from .travis.yml because it's not currently codesigned by Travis CI.

Version: 2021.10.8

    Git issue 428: match hangs on the following example - possible infinite loop?

    Fixed miscalculation of total error count when there's more than one fuzzy term.

Version: 2021.9.30

    Git issue 427: Possible bug with BESTMATCH

Version: 2021.9.24

    Updated to Unicode 14.0.0.

Version: 2021.8.27

    Git issue 421: 2021.8.27 results in "Fatal Python error: Segmentation fault"

    Fixed problems with use of fast searching tables in opposite direction.

Version: 2021.8.27

    Git issue 420: segmentation fault in finditer (maybe others)

    Fixed a bugs in fast searches in reverse direction.

Version: 2021.8.21

    Updated version.

Version: 2021.8.3

    Forgot to update version!

Version: 2021.7.6

    Additional fix for Git issue 415.

Version: 2021.7.5

    Git issue 415: Fuzzy character restrictions don't apply to insertions at "right edge"

Version: 2021.7.1

    Git issue 407: API is not a drop-in replacement for python's re when it comes to typing

    Now exports Match object as well as Pattern object.

    Git issue 414: Memory optimization questions

    sys.getsizeof returns a more accurate size of a pattern object. It includes the size of internal data, but, as is the norm, does not include the size of public objects.

Version: 2021.4.4

    Git issue 408: regex fails with a quantified backreference but succeeds with repeated backref
    Git issue 407: API is not a drop-in replacement for python's re when it comes to typing

Version: 2021.3.17

    Git issue 403: Fuzzy matching with wrong distance (unnecessary substitutions)

    Reworked the fuzzy matching code.

Version: 2020.11.13

    Git issue 394: Unexpected behaviour in fuzzy matching with limited character set with IGNORECASE flag

Version: 2020.11.11

    Update version.

Version: 2020.11.2

    Updated list of supported Python versions.

    Added .travis.yml file.

Version: 2020.10.28

    Git issue 362: Any LICENSE work for this project?

    Changed licence to Apache 2.0 and added licence file.

Version: 2020.10.23

    Git issue 387: Compilaton flag to avoid storing compiled regexp in internal cache

    Slight reversion/revision. You can prevent explicitly-compiled patterns from being cached by using "cache_all(False)".

Version: 2020.10.22

    Git issue 387: Compilaton flag to avoid storing compiled regexp in internal cache

    No longer caches patterns that are compiled explicitly.

Version: 2020.10.15

    Git issue 386: GCC 10 warnings

    Fixed bugs in fuzzy_match_string_fld and fuzzy_match_group_fld.

    Added more braces around data in some Unicode tables.

Version: 2020.10.11

    Git issue 385: Comments in expressions

    Didn't parse regex comments property when in VERBOSE mode.

Version: 2020.9.27

    Git issue 383: Memory Error - regex.findall

    The problem was caused by a lazy repeat looping forever, growing the backtracking stack. Greedy repeats were OK.

Version: 2020.7.14

    Git issue 377: request: \h for horizontal space

    Added \h as an alias to [[:blank:]].

Version: 2020.6.7

    Git issue 376: Is the \L option as efficient as it can be?

    Improved performance of string sets.

Version: 2020.6.7

    Git issue 376: Is the \L option as efficient as it can be?

    Switched StringSet to use fallback method due to inefficiencies in the engine. Needs more investigation.

Version: 2020.5.14

    Git issue 372: Regression from 2020.4.4 -> 2020.5.7 in non-fuzzy matching pattern

    Changed the 'state' member that's tested in is_repeat_guarded for a fuzzy match. The previously-used member wasn't initialised in a non-fuzzy match. The new test is a better one to use anyway.

Version: 2020.5.13

    Git issue 371: Specifying character set when fuzzy-matching allows characters not in the set

    fuzzy_ext_match and fuzzy_ext_match_group_fld didn't support sets!

Version: 2020.5.7

    Git issue 370: Confusions about Fuzzy matching behavior (prob a bug?)

Version: 2020.4.4

    Updated to Unicode 13.0.0.

Version: 2020.2.20

    Git issue 365: Memory leak occurs in fuzzy match at some substitution use cases

Version: 2020.2.18

    Git issue #364: Contradictory values in fuzzy_counts and fuzzy_changes

Version: 2020.1.7

    Issue 357: New exception "ValueError: unused keyword argument" breaks use case

    Added ignore_unused keyword argument.

    Issue 359: 2020.1.7 source distribution release contains \r\n line endings

    Fixed line endings for source distribution.

    Issue 360: Invalid modeline in `_regex.c`

    Removed vim modeline.

Version: 2020.1.7

    Fix to previous change.

Version: 2019.12.21

    Hg issue 353: fuzzy changes negative indexes

    Fuzzy change positions were off by 1 for deletions.

Version: 2019.12.18

    Another complaint from Linux.

Version: 2019.12.17

    New release and upload because of problem with source distribution.

Version: 2019.12.17

    New release and upload because of previous issues.

Version: 2019.12.17

    Make changes to setup.py.

Version: 2019.12.16

    Discarded changes for Linux.

Version: 2019.12.16

    Backed out changeset: f57e64d2085b

Version: 2019.12.15

    add bdist_wheel command to setup.py

Version: 2019.12.9

    Hg issue 348: '\X' (extended grapheme cluster) can't pass Unicode's GraphemeBreakTest (12.1.0)

    Fixed a couple of bugs in unicode_at_grapheme_boundary.

Version: 2019.10.31

    Made "Additional Features" linkable.

    Updated setup.

    Minor bug fix.

Version: 2019.8.19

    Hg issue 338: specifying allowed characters when fuzzy-matching

    Added character testing to a fuzzy constraint.

Version: 2019.6.8

    Hg issue 333: error when installing regex on PyPy2.7 v7.1.1 on Windows

    PyPy isn't officially supported, but this might fix it!

Version: 2019.6.5

    Updated for Python 3.8.

Version: 2019.6.2

    Updated to Unicode 12.1.0.

Version: 2019.5.25

    Hg issue 329: Wrong group matches when question mark quantifier is used within a look behind

    REPEAT_ONE was backtracking in the wrong direction, so it never hit the limit.

Version: 2019.4.14

    Hg issue 327: .fullmatch() causes MemoryError

    For fullmatch, added check for end/start of string for RE_OP_SUCCESS in try_match.

Version: 2019.4.12

    Missing brace in 'state_fini'.

Version: 2019.4.10

    Hg issue 325: module docstring not accessible

    Additional fix for regex_3/regex.py.

    Hg issue 326: Version is out of sync with PyPI

Version: 2019.3.12

    Hg issue 319: Support for a timespan parameter

    Added timeout parameter in Python 3. TimeoutError was added in Python 3.3, and as Python 2.7 will soon reach EOL, I'm not bothered about supporting timeouts for Python 2.

Version: 2019.3.9

    Hg issue 320: Abnormal performance

    Forgot about negative lookarounds! Previous change now applies only to positive lookarounds.

Version: 2019.3.8

    Hg issue 320: Abnormal performance

    Included firstset from lookaround, where appropriate.

Version: 2019.2.21

    Hg issue 316: __version__ no longer accessible via regex.__version__

Version: 2019.2.20

    Hg issue 314: Import error: "No module named regex._regex_core"

    Was OK for wheels, but not for setup.py.

Version: 2019.2.19

    Hg issue 313: test_regex.py ends up in site-packages/test_regex.py

    Tidied files away into subfolder in site-packages.

Version: 2019.2.18

    Fixed bug in unicode_at_grapheme_boundary.

Version: 2019.2.7

    Moved some StateData declarations to make the code conform to the C89 standard.

Version: 2019.2.6

    Lookarounds no longer save the repeat data. Lookarounds no longer saves captures if they don't contain any groups.

Version: 2019.2.5

    Atomic groups no longer save the repeat data; that proved to be unnecessary.

Version: 2019.2.3

    Further improvements to the new code.

Version: 2019.1.24

    Hg issue 308: infinite search

    Fixed a re-allocation bug.

Version: 2019.1.23

    Major overhaul of code to use simpler stacks. The result is now much easier to understand and maintain!

Version: 2018.11.22

    Hg issue 304: Unreasonable edge case that used to work

    Now moves the minimum number of repeats out of a repeat if it contains a repeat. This allows a repeat guard to be put back, which reduces the chance of catastrophic backtracking.

Version: 2018.11.7

    Hg issue 301: TypeError: character mapping must return integer, None or unicode

    Fixed bug introduced by broken workflow.

Version: 2018.11.6

    Hg issue 300: segmentation fault

    Fixed a problem with not recording all fuzzy changes.

    Also fixed the check for prefix/suffix in branches: when fuzzy subpatterns were compared, their constraints weren't compared.

Version: 2018.11.3

    Hg issue 299

    Reworked the fix to perform a normal match and then fall back to a partial match if that was originally requested.

Version: 2018.11.2

    Hg issue 299: Partial gives misleading results with "open ended" regexp

    Added checks for end of text at start and end of repeats.

Version: 2018.8.29

    Hg issue 293: scx (Script Extensions) property currently matches incorrectly

    One of the tables for Script Extensions was partly incorrectly ordered.

Version: 2018.8.17

    Hg issue 291: Include Script Extensions as a supported Unicode property

    Added the Unicode Script Extensions property.

Version: 2018.7.11

    Hg issue #289: Regex and Python typing

    Added types for Pattern and Match.

    Hg issue #290: Turkish locale causes import of regex to fail

    str (bytestring) in Python 2 is locale-sensitive. Added a function to uppercase ASCII-range letters in a locale-insensitive way.

Version: 2018.6.21

    Hg issue 286: Regex matches with `re` but not with `regex` module

Version: 2018.6.20

    The reported positions of fuzzy changes were sometimes incorrect.

Version: 2018.6.9

    Updated Unicode word and grapheme boundaries for Unicode 11.0.0, which I had overlooked... :-(

Version: 2018.6.6

    Correction to filenames.

Version: 2018.6.5

    Updated to Unicode 11.0.0.

Version: 2018.2.21

    Hg issue 276: Partial Matches yield incorrect matches and bounds

    Fixed an off-by-one bug where a lazy repeat is followed by a character (quick check).

Version: 2018.2.8

    Hg issue 273: Missing unicode normalization quick check properties

    The Unicode normalization quick check properties weren't handled correctly.

Version: 2018.2.3

    Hg issue 271: Comment logic different between Re and Regex
    Hg issue 273: Missing unicode normalization quick check properties

    Made comments consistent with re module.

    Added more Unicode properties.

Version: 2018.1.10

    Further changes to match re module's behaviour on zero-width matching for Python 3.7.

    Changes to the locations of the source files.

Version: 2017.12.12

    Hg issue 268: Update the escape() documentation

    Added documentation for escape.

    Hg issue 269: Building a bdist using setuptools throws an error.

    Moved source files from subfolders to main folders for Python versions.

Version: 2017.12.9

    Further changes to match re module's behaviour on zero-width matching for Python 3.7.

Version: 2017.12.5

    Hg issue 266: fuzzy match alignment recovery

    Added 'fuzzy_changes' attribute to match object to indicate positions of changes in fuzzy match.

    Stopped supporting Python 2.5 and Python 3.1-3.2.

    Made changes to zero-width matching for Python 3.7.

Version: 2017.11.9

    Hg issue 264: Failure to import regex in pypy3-5.8.0

Version: 2017.11.8

    Hg issue 264: Failure to import regex in pypy3-5.8.0
    Hg issue 265: Invalid pointer in munmap_chunk (core dump) for specific inputs

Version: 2017.9.23

    Hg issue 253: Run into error under PyPy 5.8.0

Version: 2017.8.1

    Hg issue #240: Unable to build the project from source on OSX with PyPy3.5-5.7.1-beta

    Needed to compensate for the differences between CPython and PyPy.

Version: 2017.4.6

    Added setup.py for building from the Hg working directory.

Version: 2017.4.6

    Hg issue 236: Incorrect references to bugs.python.org issues

Version: 2017.2.8

    Failed to build on AIX using xlc because FALSE and TRUE were already #define'd. Replaced enum {FALSE, TRUE} with #define's.

Version: 2017.1.17

    Hg issue 230: Is it a bug of (?(DEFINE)...)

    Capture groups in (?(DEFINE)...) shouldn't be treated as 'visible' capture groups by .findall.

Version: 2017.1.14

    Hg issue 227: Performance trap of (?V1i) flags

    Further improvements. It now tries to split full case-folded literals into simple and full case-folded literals where full case-folding isn't needed because simple case-folding is faster.

Version: 2017.1.13

    Hg issue 227: Performance trap of (?V1i) flags

Version: 2016.12.27

    Hg issue 227: Incorrect behavior for ? operator with UNICODE + IGNORECASE

    'end_pos' wasn't always initialised in 'locate_required_string'.

Version: 2016.11.21

    Hg issue 226: Error matching at start of string

    Fuzzy matching of zero-width items wasn't quite right.

Version: 2016.11.18

    Hg issue 225: BESTMATCH in fuzzy match not working

Version: 2016.10.22

    Hg issue 221: Got an exception using PyPy

    pypy2-v5.4.1 appears not to support the buffer protocol on bytestrings (str in Python 2), so added code to handle them analogously to how unicode strings are handled.

Version: 2016.10.20

    Make setup use setuptools if it's available.

Version: 2016.10.12

    Hg issue 221: Got an exception using PyPy

    Added check for error in fold_case which, I hope, will reveal the exception that it's not reporting.

Version: 2016.9.22

    Hg issue 220: Misbehavior of group capture with OR operand

    Repeats should not be factored out of branches because a branch should be exhausted before trying the next one.

Version: 2016.9.13

    Also supported on Python 3.6.

Version: 2016.8.27

    Hg issue 219: Unicode word boundries

    For a Unicode word boundary (UAX #29), apostrophe in rule WB5a should include both U+0027 (APOSTROPHE) and U+2019 (RIGHT SINGLE QUOTATION MARK /
     * curly apostrophe).

Version: 2016.7.21

    Hg issue 217: Core dump in conditional ahead match and matching \! character

    Fixed bug where it incorrectly tried to restore saved groups when none saved.

Version: 2016.7.14

    Hg Issue 216: Invalid match when using negative lookbehind and pipe

    The creation and position of a branch firstset wasn't always correct.

Version: 2016.6.25

    Updated to support Unicode 9.0.0.

Version: 2016.6.19

    Hg issue 214: tests failure when using python debug flavor

    Further tweaks re error handling.

Version: 2016.6.14

    Hg issue 213: Segmentation Fault

    Info about atomic groups wasn't pushed properly.

Version: 2016.6.5

    Hg issue 212: Unexpected matching difference with .*? between re and regex

    In 'add_repeat_guards', it wasn't propagating the status from the tail back towards the head across default nodes, so the guards weren't always correct.

Version: 2016.6.2

    Hg issue 211: Segmentation fault with recursive matches and atomic groups

    It wasn't saving the call frame and then restoring it when backtracking out of atomic groups.

Version: 2016.5.23

    Hg issue 206: Incompatible with re if single { in the pattern

    Brought the regex module's handling more in line with the re module. It now more readily treats an invalid fuzzy constraint as a literal.

Version: 2016.5.15

    Hg issue 208: Named list, (?ri) flags, Backreference

    Fixed more issues with the alignment of text in a buffer when using named lists.

    Also changed how a compiled regex is pickled to use a bytestring for the packed code list. (It was actually pickling an unpacked list of ints.)

Version: 2016.5.14

    Hg issue 205: Named list and (?ri) flags

    string_set_match_ign_fwdrev wasn't taking into account that it fills the folded buffer from the end when searching in reverse.

Version: 2016.5.13

    Hg issue 204: confusion of (?aif) flags

    The FULLCASE flag is now ignored if the ASCII flag is turned on.

Version: 2016.4.25

    Hg issue 203: partial matching bug

    The text position wasn't always set correctly before returning the status.

Version: 2016.4.16

    Hg issue 201: ENHANCEMATCH crashes interpreter

    Fixed an issue with restoring group captures.

Version: 2016.4.7

    Hg issue 199: Segfault in re.compile

    Removed copies of groups that weren't called.

Version: 2016.4.3

    Hg issue 197: ValueError in regex.compile
    Hg issue 198: ValueError in regex.compile

    It wasn't catching ValueError and then raising regex.error.

Version: 2016.4.2

    Hg issue 196: Fuzzy matching on repeated regex not working as expected

    Also reduced memory usage of pickle data.

Version: 2016.3.31

    # Hg issue #194: .FULLCASE and Backreference

    Capture groups failed to match when using full case folding because of a bug in the handling of "I", which needs to be treated specially to cope with the Turkic I).

Version: 2016.3.26

    Hg issue #193: Alternation and .REVERSE flag.

    The firstset before a branch was at the wrong end for a reverse pattern.

    Added back some tests that were accidentally omitted.

Version: 2016.3.24

    Hg issue 192: Named lists reverse matching doesn't work with IGNORECASE and V1

    string_set_match_fld_fwdrev wasn't taking into account that it fills the folded buffer from the end when searching in reverse.

Version: 2016.3.2

    Hg issue 190: Regression? Neverending regexp when upgrading to latest version.

    The fix for Hg issue 187 wasn't quite right. Managed to remove recursion entirely from 'add_repeat_guards'.

Version: 2016.2.25

    Hg issue 188: Crash during search

    Stopped calling 'try_match' recursively when the tail of a branch is a branch. Increasing alternatives to 40000 caused the stack to overflow.

Version: 2016.2.24

    Hg issue 187: Crash on Anaconda Python if large number of pattern

    Remove the recursion in 'use_nodes'. Increasing alternatives to 50000 caused the stack to overflow.

Version: 2016.2.23

    Hg issue 187: Crash on Anaconda Python if large number of pattern

    Reduced the amount of recursion in 'add_repeat_guards'. The large number of alternatives (25154) caused the stack to overflow.

Version: 2016.1.10

    Hg issue 177: Build fails on pypy (OS X 10.11, clang)

    Stripped out the #if...#endif that was added for Hg issue 135, which is no longer needed by more recent versions of PyPy.

Version: 2015.11.22

    Hg issue 180: bug of POSIX matching

    Fixed bug where the groups aren't always correct with POSIX matching.

Version: 2015.11.14

    Hg issue 172: Performance of V1 mode

    Fixed bug where RE_FLAG_FULLCASE not turned off when RE_FLAG_IGNORECASE turned off, leading to omission of first set.

Version: 2015.11.12

    Hg issue 171: Weird performance of V1 mode

    Fixed bug where RE_FLAG_FULLCASE not turned off when RE_FLAG_IGNORECASE turned off for required string, leading to required string not being used.

Version: 2015.11.9

    Hg issue 169: Performance

    Further tweaks to fuzzy matching.

Version: 2015.11.8

    Hg issue 167: Performance of Backreference

    No longer saves/restores groups or repeats around a lookaround if it doesn't contain any.

Version: 2015.11.7

    Hg issue 166: Performance

    Improved the performance of fuzzy matching.

Version: 2015.11.5

    Hg issue 165: Performance / hung search

    Made changes to fuzzy matching code, including refactoring different kind of fuzzy matching (exact/simple/enhanced/best).

Version: 2015.10.28

    Hg issue 163: allow lookarounds in conditionals

    Added support for a lookaround in a conditional pattern, e.g. r'(?(?=\d)\d+\b|\w+)'.

Version: 2015.10.22

     Hg issue 161: Unexpected fuzzy match results

     Fixed the bug and did some related tidying up.

Version: 2015.10.5

    Hg issue 158: Group issue with (?(DEFINE)...)

    The groups and repeats weren't restored properly when a lookaround completed and it contained a group call.

Version: 2015.10.1

    Hg issue 157: regression: segfault on complex lookaround

    Nested lookarounds/atomic groups didn't restore state correctly.

Version: 2015.9.28

    Hg issue 156: regression on atomic grouping

    It didn't initialise min_width when building the atomic group.

Version: 2015.9.23

    Hg issue 154: Segmentation fault 11 when working with an atomic group

Version: 2015.9.15

    Hg issue 150: Have an option for POSIX-compatible longest match of alternates

    Added POSIX matching (leftmost longest).

Version: 2015.7.20

    Hg issue #147: Fuzzy match can return match points beyond buffer end

    It wasn't checking for the edge of the text when case-folding and it was also advancing even when case-folding had failed.

Version: 2015.7.12

    Hg issue #146: Forced-fail (?!) works improperly in conditional

    Empty negative lookarounds weren't optimised correctly.

    The capture groups weren't being cleared before retrying after failure.

Version: 2015.6.24

    Hg issue #144: Latest version problem with matching 'R|R'

    The prefix of a set of branches was omitted.

Version: 2015.6.21

    Hg issue #143: Partial matches have incorrect span if prefix is '.' wildcard

    Didn't set state->match_pos if search_start returned a partial match status.

Version: 2015.6.19

    Updated to Unicode 8.0.

    Some performance tweaks.

Version: 2015.6.15

    Removed a few lines that should've been removed in the previous fix!

Version: 2015.6.14

    Fixed a bug where it could sometimes search for the same required string multiple times.

Version: 2015.6.10

    Hg issue #141: Crash on a certain partial match

    It didn't check the result of 'try_match' correctly in certain places (the status returned isn't limited to success and failure).

Version: 2015.6.9

    Hg issue #140: Replace with REVERSE and groups has unexpected behavior

    subx needed to add the template items to the list in reverse order when searching backwards because the list will be reversed after completion.

Version: 2015.6.4

    Hg issue #98: regex module is not thread safe because of _cache

    Now iterates over a snapshot of the cache keys in case the dict resizes.

Version: 2015.6.2

    Hg issue #139: Regular expression with multiple wildcards where first should match empty string does not always work

    The problem was caused by a negative-character in the firstset, eg "[^a]".

    Fixed.

Version: 2015.5.28

    Hg issue #137: Posix character class :punct: does not seem to be supported

    It _is_ supported.

    Corrected Posix-style properties for 'alnum', 'digit', 'punct' and 'xdigit' which are different from that of Unicode. Now also available as \p[posix_alnum}, etc.

    Hg issue  #138: grapheme anchored search not working properly

    Fixed.

Version: 2015.5.10

    Hg issue #136: Use a DFA when possible

    Made a slight tweak so that it now treats an optional subpattern like a repeated subpattern (e.g. "(?:xyz)?" -> "(?:xyz){0,1}") to make use of the repeat guards.

    The advantage over DFA is that it'll work even for those patterns that aren't compatible with DFA.

Version: 2015.5.7

    Hg issue 135: PyPy Support (with patch)

    It should now build on PyPy.

Version: 2015.3.18

    Hg issue 133: support for captures() in expandf().

    Now supported in expandf and subf.

    Issue 23692: Undocumented feature prevents re module from finding certain matches

    This also applied to regex which failed to take into account group references by group capture testa, e.g. "(?(1)...|...)", when guarding against excessive repeats.

Version: 2014.12.24

    Hg issue 132: index out of range on null property \p{}

    It's now reported as an unknown property.

Version: 2014.12.15

    Hg issue 131: nested sets behaviour

    The set difference operator '--' wasn't handled correctly after an implicit set union.

Version: 2014.11.14

    Unreported issue: no such builtin as 'ascii' in Python 2. Fixed.

Version: 2014.11.13

    Hg issue 127: Infinite loop is found

    Not an infinite loop, but slow because of repeated backtracking on a very long chunk of text.

    This fix reduces the amount of backtracking and re-matching.

Version: 2014.11.3

    Hg issue 125: Reference to entire match (\g<0>) in Pattern.sub() doesn't work as of 2014.09.22 release.

Version: 2014.10.24

    Reverted licence.

Version: 2014.10.23

    Fixed bug in determining line number in regex.

    Changed licence to Apache License 2.0 and included copy in release.

Version: 2014.10.9

    Issue 22578: Add additional attributes to re.error

    Added the attributes .msg, .pattern, .pos, .lineno and .colno to the regex error class.

Version: 2014.10.7

    Fixed bug in partial matching when required string occurs after repeat.

Version: 2014.9.22

    Issue #22437: Added support for referring to a group by number using (?P=...). This is in addition to the existing \g<...>.

    Fixed bug in handling of cache for locale-sensitive patterns.

Version: 2014.9.18

    Adjusted line-endings in PKG-INFO.

Version: 2014.8.15

    Hg issue 115: Infinite loop when processing backreferences

Version: 2014.6.28

    Updated to Unicode 7.0.

Version: 2014.5.23

    Fixed fuzzy counts that were wrong when using BESTMATCH or ENHANCEMATCH flags.

Version: 2014.5.17

    Hg issue 112 in mrab-regex-hg: re: OK, but regex: SystemError

Version: 2014.4.10

    Hg issue 102: Partial matches
    Hg issue 109: Edit distance of fuzzy match

    Added partial matches.
    Added .fuzzy_counts attribute to match objects.

Version: 2014.2.19

    Unicode properties sometimes failed to match when the IGNORECASE flag was set.

Version: 2014.2.16

    Hg issue 108: Fails to build from source on s390x

Version: 2014.1.30

    Hg issue 106: * operator not working correctly with sub()

    Made to conform more to re module in version 0 behaviour.

Version: 2014.1.20

    Hg issue 105: FAIL: test_case_folding (__main__.RegexTests) with py2.7

    data.fold_len wasn't initialised.

    Also, deleted some unused functions.

Version: 2014.1.10

    Issue #17087: Improve the repr for regular expression match objects

Version: 2013.12.31

    Hg issue 101: findall() broken (seems like memory corruption)

    state->req_pos wasn't initialised when the required string is an initial string.

Version: 2013.11.29

    Hg issue 100: strange results from regex.search

Version: 2013.10.25

    Hg issue 98: regex module is not thread safe because of _cache

Version: 2013.10.24

    Further fixes for Hg issue 96.

    It should now use correctly use sets for named lists, except when there's fuzzy matching.

Version: 2013.10.23

    Hg issue 96: compile '\L<...>' with 'i' flag was very slow

Version: 2013.10.22

    Hg issue 95: 'pos' for regex.error

Version: 2013.10.21

    Python crashes when executing regex updates pattern.findall

Version: 2013.10.12

    Updated to Unicode 6.3.

Version: 2013.10.4

    Issue #18468: re.group() should never return a bytearray

    Applies to Python 3.4 and later for compatibility with the re module.

    Also, some performance improvements.

Version: 2013.8.4

    Update for Python 3.4a1 release.

Version: 2013.6.26

    Performance improvements.

Version: 2013.6.5

    Hg issue 92: running the following regex causes a segfault

Version: 2013.5.21

    Hg issue 91: match.expand is extremely slow

    Also tidied up code.

Version: 2013.3.11

    Hg issue 89: Certain regexes extremely slow compared to re module

    Disabled one of the optimisations that appears to cause performance problems.

Version: 2013.2.22

    Fixed issue with LOCALE flag not working properly.

Version: 2013.2.16

    Fixed a locale-specific test. Whether b'\xE0' is a word character depends on the locale.

Version: 2013.1.26

    Another fix for Hg issue 87: Allow duplicate names of groups
    It didn't correctly handle a name group within a group of the same name.

Version: 2013.1.25

    Second attempt to fix

Version: 2013.1.24

    Hg issue 86: Enhance API of captures() to enable retrieval of ALL groups at once, as a dictionary
        Added capturesdict() method to match object.

    Hg issue 87: Allow duplicate names of groups
        Now allowed.

    Hg issue 88: regex.match() hangs
        Fixed.

Version: 2013.1.20

    Hg issue 85: Non-conformance to Unicode UAX#29 re: ZWJ / ZWNJ

Version: 2012.12.16

    Hg issue 83: slash handling in presence of a quantifier

    The bug was not limited just slash!

Version: 2012.11.20

    Updated to Unicode 6.2.

Version: 2012.11.13

    Issue 16443: Add docstrings to regular expression match objects

Version: 2012.11.5

    Further performance improvements.

Version: 2012.10.31

    Performance improvements.

Version: 2012.10.17

    Added "fullmatch" method (issue #16203).

    Fixed bug (Hg issue #80). Now raises the correct error.

Version: 2012.10.8

    Added subf, subfn and expandf methods.

    Performed some refactoring.

Version: 2012.9.4

    Hg issue 78: "Captures" doesn't work for recursive calls

Version: 2012.8.25

    Added 'detach_string' method to match object.

    Made objects copyable.

Version: 2012.8.3

    Speed improvements.

Version: 2012.7.10

    Fixed bug in debug output in Python 2 version.

    Also expanded fuzzy info in debug output.

Version: 2012.7.9

    Hg issue 75: DEBUG flag

    Also made the debug output a little more readable by showing string literals and property names/values.

Version: 2012.7.8

    Hg issue 73: conditional patterns

Version: 2012.7.5

    Hg issue 71: non-greedy quantifier in lookbehind

Version: 2012.6.13

    Hg issue 69: Changing DEFAULT_VERSION does not actually work.

    DEFAULT_VERSION isn't part of the public API, but changing it should now work as expected.

Version: 2011.5.14

    Fixed bug in case-insensitive set.

Version: 2011.3.15

    Shared iterators now work in both Python 3 and Python 2.

