CHANGELOG.md

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[Unreleased]

[2.9.1] - 2024-05-11 - Janosch Müller

Fixed

• fixed unnecessary $LOAD_PATH searches at load time
  • thanks to Koichi ITO

[2.9.0] - 2024-01-07 - Janosch Müller

Added

• all expressions now respond to #negative? / #negated?
  • previously only sets, props, and posix classes did
• implemented #negative? / #negated? for more applicable expressions
  • \B, \D, \H, \S, \W, (?!...), (?<!...)

Fixed

• fixed missing support for grapheme cluster break unicode properties
  • e.g. /\p{Grapheme_Cluster_Break=Extend}/

[2.8.3] - 2023-12-04 - Janosch Müller

Fixed

• fixed scanner errors for insignificant leading zeros in numerical group refs
  • e.g. (a)\k<01>, (a)\g<-01>, (a)?(?(01)b|c)
  • thanks to Markus Schirp for the report

[2.8.2] - 2023-10-10 - Janosch Müller

Fixed

• handle a corner case where parsing redundant number escapes raised an error
  • e.g. parse(/\99/), which in Ruby is a valid Regexp that matches 99
  • thanks to Markus Schirp for the report

[2.8.1] - 2023-06-10 - Janosch Müller

Fixed

• support for extpict unicode property, added in Ruby 2.6
• support for 10 unicode script/block properties added in Ruby 3.2

[2.8.0] - 2023-04-17 - Janosch Müller

Added

• Regexp::Expression::Shared#ends_at
  • e.g. parse(/a +/x)[0].ends_at # => 3
  • e.g. parse(/a +/x)[0].ends_at(include_quantifier = false) # => 1
• Regexp::Expression::Shared#{capturing?,comment?}
  • previously only available on capturing and comment groups
• Regexp::Expression::Shared#{decorative?}
  • true for decorations: comment groups as well as comments and whitespace in x-mode
• Regexp::Expression::Shared#parent
• new format argument :original for Regexp::Expression::Base#to_s
  • includes decorative elements between node and its quantifier
  • e.g. parse(/a (?#comment) +/x)[0].to_s(:original) # => "a (?#comment) +"
  • using it is not needed when calling Root#to_s as Root can't be quantified
• support calling Subexpression#{each_expression,flat_map} with a one-argument block
  • in this case, only the expressions are passed to the block, no indices
• support calling test methods at Expression class level
  • capturing?, comment?, decorative?, referential?, terminal?
  • e.g. Regexp::Expression::CharacterSet.terminal? # => false

Fixed

• Regexp::Expression::Shared#full_length with whitespace before quantifier
  • e.g. parse(/a +/x)[0].full_length used to yield 2, now it yields 3
• Subexpression#to_s output with children with whitespace before their quantifier
  • e.g. parse(/a + /x).to_s used to yield "a+ ", now it yields "a + "
  • calling #to_s on sub-nodes still omits such decorative interludes by default
    • use new #to_s format :original to include it
    • e.g. parse(/a + /x)[0].to_s(:original) # => "a +"
• fixed Subexpression#te behaving differently from other expressions
  • only Subexpression#te used to include the quantifier
  • now #te is the end index without quantifier, as for other expressions
• fixed NoMethodError when calling #starts_at or #ts on empty sequences
  • e.g. Regexp::Parser.parse(/|/)[0].starts_at
  • e.g. Regexp::Parser.parse(/[&&]/)[0][0].starts_at
• fixed nested comment groups breaking local x-options
  • e.g. in /(?x:(?#hello)) /, the x-option wrongly applied to the whitespace
• fixed nested comment groups breaking conditionals
  • e.g. in /(a)(?(1)b|c(?#hello)d)e/, the 2nd conditional branch included "e"
• fixed quantifiers after comment groups being mis-assigned to that group
  • e.g. in /a(?#foo){3}/ (matches 'aaa')
• fixed Scanner accepting two cases of invalid Regexp syntax
  • unmatched closing parentheses ()) and k-backrefs with number 0 (\k<0>)
  • these are a SyntaxError in Ruby, so could only be passed as a String
  • they now raise a Regexp::Scanner::ScannerError
• fixed some scanner errors not inheriting from Regexp::Scanner::ScannerError
• reduced verbosity of inspect / pretty print output

[2.7.0] - 2023-02-08 - Janosch Müller

Added

• Regexp::Lexer.lex now streams tokens when called with a block
  • it can now take arbitrarily large input, just like Regexp::Scanner
  • this also slightly improves Regexp::Parser.parse performance
  • note: Regexp::Parser.parse still does not and will not support streaming
• improved performance of Subexpression#each_expression
• minor improvements to Regexp::Scanner performance
• overall improvement of parse performance: about 10% for large Regexps

Fixed

• parsing of octal escape sequences in sets, e.g. [\141]
  • thanks to Randy Stauner for the report

[2.6.2] - 2023-01-19 - Janosch Müller

Fixed

• fixed SystemStackError when cloning recursive subexpression calls
  • e.g. Regexp::Parser.parse(/a|b\g<0>/).dup

[2.6.1] - 2022-11-16 - Janosch Müller

Fixed

• fixed scanning of two negative lookbehind edge cases
  • (?<!x)y> used to raise a ScannerError
  • (?<!x>)y used to be misinterpreted as a named group
  • thanks to Sergio Medina for the report

[2.6.0] - 2022-09-26 - Janosch Müller

Fixed

• fixed #referenced_expression for \g<0> (was nil, is now the Root exp)
• fixed #reference, #referenced_expression for recursion level backrefs
  • e.g. (a)(b)\k<-1+1>
  • #referenced_expression was nil, now it is the correct Group exp
• detect and raise for two more syntax errors when parsing String input
  • quantification of option switches (e.g. (?i)+)
  • invalid references (e.g. /\k<1>/)
  • these are a SyntaxError in Ruby, so could only be passed as a String

Added

• Regexp::Expression::Base#human_name
  • returns a nice, human-readable description of the expression
• Regexp::Expression::Base#optional?
  • returns true if the expression is quantified accordingly (e.g. with *, {,n})
• added a deprecation warning when calling #to_re on set members

[2.5.0] - 2022-05-27 - Janosch Müller

Added

• Regexp::Expression::Base.construct and .token_class methods
  • see the wiki for details

[2.4.0] - 2022-05-09 - Janosch Müller

Fixed

• fixed interpretation of + and ? after interval quantifiers ({n,n})
  • they used to be treated as reluctant or possessive mode indicators
  • however, Ruby does not support these modes for interval quantifiers
  • they are now treated as chained quantifiers instead, as Ruby does it
  • c.f. #3
• fixed Expression::Base#nesting_level for some tree rewrite cases
  • e.g. the alternatives in /a|[b]/ had an inconsistent nesting_level
• fixed Scanner accepting invalid posix classes, e.g. [[:foo:]]
  • they raise a SyntaxError when used in a Regexp, so could only be passed as String
  • they now raise a Regexp::Scanner::ValidationError in the Scanner

Added

• added Expression::Base#== for (deep) comparison of expressions

• added Expression::Base#parts

  • returns the text elements and subexpressions of an expression
  • e.g. parse(/(a)/)[0].parts # => ["(", #<Literal @text="a"...>, ")"]

• added Expression::Base#te (a.k.a. token end index)

  • Expression::Subexpression always had #te, only terminal nodes lacked it so far

• made some Expression::Base methods available on Quantifier instances, too

  • #type, #type?, #is?, #one_of?, #options, #terminal?
  • #base_length, #full_length, #starts_at, #te, #ts, #offset
  • #conditional_level, #level, #nesting_level , #set_level
  • this allows a more unified handling with Expression::Base instances

• allowed Quantifier#initialize to take a token and options Hash like other nodes

• added a deprecation warning for initializing Quantifiers with 4+ arguments:

  Calling Expression::Base#quantify or Quantifier.new with 4+ arguments is deprecated.

  It will no longer be supported in regexp_parser v3.0.0.

  Please pass a Regexp::Token instead, e.g. replace token, text, min, max, mode with ::Regexp::Token.new(:quantifier, token, text). min, max, and mode will be derived automatically.

  Or do exp.quantifier = Quantifier.construct(token: token, text: str).

  This is consistent with how Expression::Base instances are created.

[2.3.1] - 2022-04-24 - Janosch Müller

Fixed

• removed five inexistent unicode properties from Syntax#features
  • these were never supported by Ruby or the Regexp::Scanner
  • thanks to Markus Schirp for the report

[2.3.0] - 2022-04-08 - Janosch Müller

Added

• improved parsing performance through Syntax refactoring
  • instead of fresh Syntax instances, pre-loaded constants are now re-used
  • this approximately doubles the parsing speed for simple regexps
• added methods to Syntax classes to show relative feature sets
  • e.g. Regexp::Syntax::V3_2_0.added_features
• support for new unicode properties of Ruby 3.2 / Unicode 14.0

[2.2.1] - 2022-02-11 - Janosch Müller

Fixed

• fixed Syntax version of absence groups ((?~...))
  • the lexer accepted them for any Ruby version
  • now they are only recognized for Ruby >= 2.4.1 in which they were introduced
• reduced gem size by excluding specs from package
• removed deprecated test_files gemspec setting
• no longer depend on yaml/psych (except for Ruby <= 2.4)
• no longer depend on set
  • set was removed from the stdlib and made a standalone gem as of Ruby 3
  • this made it a hidden/undeclared dependency of regexp_parser

[2.2.0] - 2021-12-04 - Janosch Müller

Added

• added support for 13 new unicode properties introduced in Ruby 3.1.0

[2.1.1] - 2021-02-23 - Janosch Müller

Fixed

• fixed NameError when requiring only 'regexp_parser/scanner' in v2.1.0
  • thanks to Jared White and Sam Ruby for the report

[2.1.0] - 2021-02-22 - Janosch Müller

Added

• common ancestor for all scanning/parsing/lexing errors
  • Regexp::Parser::Error can now be rescued as a catch-all
  • the following errors (and their many descendants) now inherit from it:
    • Regexp::Expression::Conditional::TooManyBranches
    • Regexp::Parser::ParserError
    • Regexp::Scanner::ScannerError
    • Regexp::Scanner::ValidationError
    • Regexp::Syntax::SyntaxError
  • it replaces ArgumentError in some rare cases (Regexp::Parser.parse('?'))
  • thanks to sandstrom for the cue

Fixed

• fixed scanning of whole-pattern recursion calls \g<0> and \g'0'
  • a regression in v2.0.1 had caused them to be scanned as literals
• fixed scanning of some backreference and subexpression call edge cases
  • e.g. \k<+1>, \g<x-1>
• fixed tokenization of some escapes in character sets
  • ., |, {, }, (, ), ^, $, ?, +, *
  • all of these correctly emitted #type :literal and #token :literal if not escaped
  • if escaped, they emitted e.g. #type :escape and #token :group_open for [\(]
  • the escaped versions now correctly emit #type :escape and #token :literal
• fixed handling of control/metacontrol escapes in character sets
  • e.g. [\cX], [\M-\C-X]
  • they were misread as bunch of individual literals, escapes, and ranges
• fixed some cases where calling #dup/#clone on expressions led to shared state

[2.0.3] - 2020-12-28 - Janosch Müller

Fixed

• fixed error when scanning some unlikely and redundant but valid charset patterns
  • e.g. /[[.a-b.]]/, /[[=e=]]/,
• fixed ancestry of some error classes related to syntax version lookup
  • NotImplementedError, InvalidVersionNameError, UnknownSyntaxNameError
  • they now correctly inherit from Regexp::Syntax::SyntaxError instead of Rubys ::SyntaxError

[2.0.2] - 2020-12-25 - Janosch Müller

Fixed

• fixed FrozenError when calling #to_s on a frozen Group::Passive
  • thanks to Daniel Gollahon

[2.0.1] - 2020-12-20 - Janosch Müller

Fixed

• fixed error when scanning some group names
  • this affected names containing hyphens, digits or multibyte chars, e.g. /(?<a1>a)/
  • thanks to Daniel Gollahon for the report
• fixed error when scanning hex escapes with just one hex digit
  • e.g. /\x0A/ was scanned correctly, but the equivalent /\xA/ was not
  • thanks to Daniel Gollahon for the report

[2.0.0] - 2020-11-25 - Janosch Müller

Changed

• some methods that used to return byte-based indices now return char-based indices
  • the returned values have only changed for Regexps that contain multibyte chars
  • this is only a breaking change if you used such methods directly AND relied on them pointing to bytes
  • affected methods:
  • Regexp::Token #length, #offset, #te, #ts
  • Regexp::Expression::Base #full_length, #offset, #starts_at, #te, #ts
  • thanks to Akinori MUSHA for the report
• removed some deprecated methods/signatures
  • these are rarely used and have been showing deprecation warnings for a long time
  • Regexp::Expression::Subexpression.new with 3 arguments
  • Regexp::Expression::Root.new without a token argument
  • Regexp::Expression.parsed

Added

• Regexp::Expression::Base#base_length
  • returns the character count of an expression body, ignoring any quantifier
• pragmatic, experimental support for chained quantifiers
  • e.g.: /^a{10}{4,6}$/ matches exactly 40, 50 or 60 as
  • successive quantifiers used to be silently dropped by the parser
  • they are now wrapped with passive groups as if they were written (?:a{10}){4,6}
  • thanks to calfeld for reporting this a while back

Fixed

• incorrect encoding output for non-ascii comments
  • this led to a crash when calling #to_s on parse results containing such comments
  • thanks to Michael Glass for the report
• some crashes when scanning contrived patterns such as '\😋'

[1.8.2] - 2020-10-11 - Janosch Müller

Fixed

• fix FrozenError in Expression::Base#repetitions on Ruby 3.0
  • thanks to Thomas Walpole
• removed "unknown future version" warning on Ruby 3.0

[1.8.1] - 2020-09-28 - Janosch Müller

Fixed

• fixed scanning of comment-like text in normal mode
  • this was an old bug, but had become more prevalent in v1.8.0
  • thanks to Tietew for the report
• specified correct minimum Ruby version in gemspec
  • it said 1.9 but really required 2.0 as of v1.8.0

[1.8.0] - 2020-09-20 - Janosch Müller

Changed

• dropped support for running on Ruby 1.9.x

Added

• regexp flags can now be passed when parsing a String as regexp body
  • see the README for details
  • thanks to Owen Stephens
• bare occurrences of \g and \k are now allowed and scanned as literal escapes
  • matches Onigmo behavior
  • thanks for the report to Marc-André Lafortune

Fixed

• fixed parsing comments without preceding space or trailing newline in x-mode
  • thanks to Owen Stephens

[1.7.1] - 2020-06-07 - Ammar Ali

Fixed

• Support for literals that include the unescaped delimiters {, }, and ]. These delimiters are informally supported by various regexp engines.

[1.7.0] - 2020-02-23 - Janosch Müller

Added

• Expression::Base#each_expression and #traverse can now be called without a block
  • this returns an Enumerator and allows chaining, e.g. each_expression.select
  • thanks to Masataka Kuwabara

Fixed

• MatchLength#each no longer ignores the given limit: when called without a block

[1.6.0] - 2019-06-16 - Janosch Müller

Added

• Added support for 16 new unicode properties introduced in Ruby 2.6.2 and 2.6.3

[1.5.1] - 2019-05-23 - Janosch Müller

Fixed

• Fixed #options (and thus #i?, #u? etc.) not being set for some expressions:
  • this affected posix classes as well as alternation, conditional, and intersection branches
  • #options was already correct for all child expressions of such branches
  • this only made an operational difference for posix classes as they respect encoding flags
• Fixed #options not respecting all negative options in weird cases like '(?u-m-x)'
• Fixed Group#option_changes not accounting for indirectly disabled (overridden) encoding flags
• Fixed Scanner allowing negative encoding options if there were no positive options, e.g. '(?-u)'
• Fixed ScannerError for some valid meta/control sequences such as '\C-\\'
• Fixed Expression::Base#match and #=~ not working with a single argument

[1.5.0] - 2019-05-14 - Janosch Müller

Added

• Added #referenced_expression for backrefs, subexp calls and conditionals
  • returns the Group expression that is being referenced via name or number
• Added Expression::Base#repetitions
  • returns a Range of allowed repetitions (1..1 if there is no quantifier)
  • like #quantity but with a more uniform interface
• Added Expression::Base#match_length
  • allows to inspect and iterate over String lengths matched by the Expression

Fixed

• Fixed Expression::Base#clone "direction"
  • it used to dup ivars onto the callee, leaving only the clone referencing the original objects
  • this will affect you if you call #eql?/#equal? on expressions or use them as Hash keys
• Fixed #clone results for Sequences, e.g. alternations and conditionals
  • the inner #text was cloned onto the Sequence and thus duplicated
  • e.g. Regexp::Parser.parse(/(a|bc)/).clone.to_s # => (aa|bcbc)
• Fixed inconsistent #to_s output for Sequences
  • it used to return only the "specific" text, e.g. "|" for an alternation
  • now it includes nested expressions as it does for all other Subexpressions
• Fixed quantification of codepoint lists with more than one entry (\u{62 63 64}+)
  • quantifiers apply only to the last entry, so this token is now split up if quantified

[1.4.0] - 2019-04-02 - Janosch Müller

Added

• Added support for 19 new unicode properties introduced in Ruby 2.6.0

[1.3.0] - 2018-11-14 - Janosch Müller

Added

• Syntax#features returns a Hash of all types and tokens supported by a given Syntax

Fixed

• Thanks to Akira Matsuda
  • eliminated warning "assigned but unused variable - testEof"

[1.2.0] - 2018-09-28 - Janosch Müller

Added

• Subexpression (branch node) includes Enumerable, allowing to #select children etc.

Fixed

• Fixed missing quantifier in Conditional::Expression methods #to_s, #to_re
• Conditional::Condition no longer lives outside the recursive #expressions tree
  • it used to be the only expression stored in a custom ivar, complicating traversal
  • its setter and getter (#condition=, #condition) still work as before

[1.1.0] - 2018-09-17 - Janosch Müller

Added

• Added Quantifier methods #greedy?, #possessive?, #reluctant?/#lazy?
• Added Group::Options#option_changes
  • shows the options enabled or disabled by the given options group
  • as with all other expressions, #options shows the overall active options
• Added Conditional#reference and Condition#reference, indicating the determinative group
• Added Subexpression#dig, acts like Array#dig

Fixed

• Fixed parsing of quantified conditional expressions (quantifiers were assigned to the wrong expression)
• Fixed scanning and parsing of forward-referring subexpression calls (e.g. \g<+1>)
• Root and Sequence expressions now support the same constructor signature as all other expressions

[1.0.0] - 2018-09-01 - Janosch Müller

This release includes several breaking changes, mostly to character sets, #map and properties.

Changed

• Changed handling of sets (a.k.a. character classes or "bracket expressions")
  • see PR #55 / issue #47 for details
  • sets are now parsed to expression trees like other nestable expressions
  • #scan now emits the same tokens as outside sets (no longer :set, :member)
  • CharacterSet#members has been removed
  • new Range and Intersection classes represent corresponding syntax features
  • a new PosixClass expression class represents e.g. [[:ascii:]]
    • PosixClass instances behave like Property ones, e.g. support #negative?
    • #scan emits :(non)posixclass, :<type> instead of :set, :char_(non)<type>
• Changed Subexpression#map to act like regular Enumerable#map
  • the old behavior is available as Subexpression#flat_map
  • e.g. parse(/[a]/).map(&:to_s) == ["[a]"]; used to be ["[a]", "a"]
• Changed expression emissions for some escape sequences
  • EscapeSequence::Codepoint, CodepointList, Hex and Octal are now all used
  • they already existed, but were all parsed as EscapeSequence::Literal
  • e.g. \x97 is now EscapeSequence::Hex instead of EscapeSequence::Literal
• Changed naming of many property tokens (emitted for \p{...})
  • if you work with these tokens, see PR #56 for details
  • e.g. :punct_dash is now :dash_punctuation
• Changed (?m) and the likes to emit as :options_switch token (@4ade4d1)
  • allows differentiating from group-local :options, e.g. (?m:.)
• Changed name of Backreference::..NestLevel to ..RecursionLevel (@4184339)
• Changed Backreference::Number#number from String to Integer (@40a2231)

Added

• Added support for all previously missing properties (about 250)
• Added Expression::UnicodeProperty#shortcut (e.g. returns "m" for \p{mark})
• Added #char(s) and #codepoint(s) methods to all EscapeSequence expressions
• Added #number/#name/#recursion_level to all backref/call expressions (@174bf21)
• Added #number and #number_at_level to capturing group expressions (@40a2231)

Fixed

• Fixed Ruby version mapping of some properties
• Fixed scanning of some property spellings, e.g. with dashes
• Fixed some incorrect property alias normalizations
• Fixed scanning of codepoint escapes with 6 digits (e.g. \u{10FFFF})
• Fixed scanning of \R and \X within sets; they act as literals there

[0.5.0] - 2018-04-29 - Janosch Müller

Changed

• Changed handling of Ruby versions (PR #53)
  • New Ruby versions are now supported by default
  • Some deep-lying APIs have changed, which should not affect most users:
    • Regexp::Syntax::VERSIONS is gone
    • Syntax version names have changed from Regexp::Syntax::Ruby::Vnnn to Regexp::Syntax::Vn_n_n
    • Syntax version classes for Ruby versions without regex feature changes are no longer predefined and are now only created on demand / lazily
    • Regexp::Syntax::supported? returns true for any argument >= 1.8.6

Fixed

• Fixed some use cases of Expression methods #strfregexp and #to_h (@e738107)

Added

• Added full signature support to collection methods of Expressions (@aa7c55a)

[0.4.13] - 2018-04-04 - Ammar Ali

• Added ruby version files for 2.2.10 and 2.3.7

[0.4.12] - 2018-03-30 - Janosch Müller

• Added ruby version files for 2.4.4 and 2.5.1

[0.4.11] - 2018-03-04 - Janosch Müller

• Fixed UnknownSyntaxNameError introduced in v0.4.10 if the gems parent dir tree included a 'ruby' dir

[0.4.10] - 2018-03-04 - Janosch Müller

• Added ruby version file for 2.6.0
• Added support for Emoji properties (available in Ruby since 2.5.0)
• Added support for XPosixPunct and Regional_Indicator properties
• Fixed parsing of Unicode 6.0 and 7.0 script properties
• Fixed parsing of the special Assigned property
• Fixed scanning of InCyrillic_Supplement property

[0.4.9] - 2017-12-25 - Ammar Ali

• Added ruby version file for 2.5.0

[0.4.8] - 2017-12-18 - Janosch Müller

• Added ruby version files for 2.2.9, 2.3.6, and 2.4.3

[0.4.7] - 2017-10-15 - Janosch Müller

• Fixed a thread safety issue (issue #45)
• Some public class methods that were only reliable for internal use are now private instance methods (PR #46)
• Improved the usefulness of Expression::Base#options (issue #43) - #options and derived methods such as #i?, #m? and #x? are now defined for all Expressions that are affected by such flags.
• Fixed scanning of whitespace following (?x) (commit 5c94bd2)
• Fixed a Parser bug where the #number attribute of traditional numerical backreferences was not set correctly (commit 851b620)

[0.4.6] - 2017-09-18 - Janosch Müller

• Added Parser support for hex escapes in sets (PR #36)
• Added Parser support for octal escapes (PR #37)
• Added support for cluster types \R and \X (PR #38)
• Added support for more metacontrol notations (PR #39)

[0.4.5] - 2017-09-17 - Ammar Ali

• Thanks to Janosch Müller](https://github.com/janosch-x):
  • Support ruby 2.2.7 (PR #42)
• Added ruby version files for 2.2.8, 2.3.5, and 2.4.2

[0.4.4] - 2017-07-10 - Ammar Ali

• Thanks to Janosch Müller](https://github.com/janosch-x):
  • Add support for new absence operator (PR #33)
• Thanks to Bartek Bułat:
  • Add support for Ruby 2.3.4 version (PR #40)

[0.4.3] - 2017-03-24 - Ammar Ali

• Added ruby version file for 2.4.1

[0.4.2] - 2017-01-10 - Ammar Ali

• Thanks to Janosch Müller](https://github.com/janosch-x):
  • Support ruby 2.4 (PR #30)
  • Improve codepoint handling (PR #27)

[0.4.1] - 2016-11-22 - Ammar Ali

• Updated ruby version file for 2.3.3

[0.4.0] - 2016-11-20 - Ammar Ali

• Added Syntax.supported? method
• Updated ruby versions for latest releases; 2.1.10, 2.2.6, and 2.3.2

[0.3.6] - 2016-06-08 - Ammar Ali

• Thanks to John Backus:
  • Remove warnings (PR #26)

[0.3.5] - 2016-05-30 - Ammar Ali

• Thanks to John Backus:
  • Fix parsing of /\xFF/n (hex:escape) (PR #24)

[0.3.4] - 2016-05-25 - Ammar Ali

• Thanks to John Backus:
  • Fix warnings (PR #19)
• Thanks to Dana Scheider:
  • Correct error in README (PR #20)
• Fixed mistyped \h and \H character types (issue #21)
• Added ancestry syntax files for latest rubies (issue #22)

[0.3.3] - 2016-04-26 - Ammar Ali

• Thanks to John Backus:
  • Fixed scanning of zero length comments (PR #12)
  • Fixed missing escape:codepoint_list syntax token (PR #14)
  • Fixed to_s for modified interval quantifiers (PR #17)

[0.3.2] - 2016-01-01 - Ammar Ali

• Updated ruby versions for latest releases; 2.1.8, 2.2.4, and 2.3.0
• Fixed class name for UnknownSyntaxNameError exception
• Added UnicodeBlocks support to the parser.
• Added UnicodeBlocks support to the scanner.
• Added expand_members method to CharacterSet, returns traditional or unicode property forms of shothands (\d, \W, \s, etc.)
• Improved meaning and output of %t and %T in strfregexp.
• Added syntax versions for ruby 2.1.4 and 2.1.5 and updated latest 2.1 version.
• Added to_h methods to Expression, Subexpression, and Quantifier.
• Added traversal methods; traverse, each_expression, and map.
• Added token/type test methods; type?, is?, and one_of?
• Added printing method strfregexp, inspired by strftime.
• Added scanning and parsing of free spacing (x mode) expressions.
• Improved handling of inline options (?mixdau:...)
• Added conditional expressions. Ruby 2.0.
• Added keep (\K) markers. Ruby 2.0.
• Added d, a, and u options. Ruby 2.0.
• Added missing meta sequences to the parser. They were supported by the scanner only.
• Renamed Lexer's method to lex, added an alias to the old name (scan)
• Use #map instead of #each to run the block in Lexer.lex.
• Replaced VERSION.yml file with a constant.
• Update tokens and scanner with new additions in Unicode 7.0.

[0.1.6] - 2014-10-06 - Ammar Ali

• Fixed test and gem building rake tasks and extracted the gem specification from the Rakefile into a .gemspec file.
• Added syntax files for missing ruby 2.x versions. These do not add extra syntax support, they just make the gem work with the newer ruby versions.
• Fixed a parser bug where an alternation sequence that contained nested expressions was incorrectly being appended to the parent expression when the nesting was exited. e.g. in /a|(b)c/, c was appended to the root.
• Fixed a bug where character types were not being correctly scanned within character sets. e.g. in [\d], two tokens were scanned; one for the backslash '' and one for the 'd'

[0.1.5] - 2014-01-14 - Ammar Ali

• Added syntax stubs for ruby versions 2.0 and 2.1
• Added clone methods for deep copying expressions.
• Added optional format argument for to_s on expressions to return the text of the expression with (:full, the default) or without (:base) its quantifier.
• Renamed the :beginning_of_line and :end_of_line tokens to :bol and :eol.
• Fixed a bug where alternations with more than two alternatives and one of them ending in a group were being incorrectly nested.
• Improved EOF handling in general and especially from sequences like hex and control escapes.
• Fixed a bug where named groups with an empty name would return a blank token [].
• Fixed a bug where member of a parent set where being added to its last subset.
• Fixed a few mutable string bugs by calling dup on the originals.
• Made ruby 1.8.6 the base for all 1.8 syntax, and the 1.8 name a pointer to the latest (1.8.7 at this time)
• Removed look-behind assertions (positive and negative) from 1.8 syntax
• Added control (\cc and \C-c) and meta (\M-c) escapes to 1.8 syntax
• The default syntax is now the one of the running ruby version in both the lexer and the parser.

[0.1.0] - 2010-11-21 - Ammar Ali

• Initial release