0.28.0

Language changes

• (breaking-change) Enum declaration members can no longer be separated by a space, only by a newline, ; or ,, the latter being deprecated and reformatted to a newline. (#7607, #7618, thanks @asterite, and @j8r)
• Add begin-less and end-less ranges: array[5..]. (#7179, thanks @asterite)
• Add offsetof(Type, @ivar) expression. (#7589, thanks @malte-v)

Macros

• Add Type#annotations to list all annotations and not just the last of each kind. (#7326, thanks @Blacksmoke16)
• Add ArrayLiteral#sort_by macro method. (#3947, thanks @jreinert)

Standard library

• (breaking-change) Allow creating None enum flag with Enum.from_value. (#6516, thanks @bew)
• (breaking-change) Add deprecation message to PartialComparable. Its behaviour has been fully integrated into Comparable. (#7664, thanks @straight-shoota)
• (performance) Optimize dwarf line numbers decoding. (#7413, thanks @asterite)
• Fix Signal::CHLD.reset not clearing previous handler. (#7409, thanks @asterite)
• Add lazy versions of Object.getter? and Object.property? macros. (#7322, thanks @Sija)
• Allow returning other values than -1, 0 and 1 by Comparable#<=>. (#7277, thanks @r00ster91)
• Add missing require statements to samples in the API docs. (#7564, thanks @Maroo-b)
• Fix example codes in multiple places. (#7569, thanks @maiha)
• Add documentation for @[Flags] and @[Link] annotations. (#7665, thanks @bcardiff)
• Add documentation for Bool. (#7651, thanks @wontruefree)
• Refactor to avoid usage of the thread-local $errno GLIBC_PRIVATE symbol. (#7496, thanks @felixvf)
• Refactor to have similar signatures accross the stdlib for #to_s and #inspect. (#7528, thanks @wontruefree)

Numeric

• (breaking-change) Add deprecation message to Int#/. It will return a Float in 0.29.0. Use Int#// for integer division. (#7639, thanks @bcardiff)
• Change Number#inspect to not show the type suffixes. (#7525, thanks @asterite)
• Add Int#leading_zeros_count and Int#trailing_zeros_count. (#7520, thanks @Sija)
• Add Big*#//, BigInt#&-ops and missing #floor, #ceil, #trunc. (#7638, thanks @bcardiff)
• Improve OverflowError message. (#7375, thanks @r00ster91)

Text

• (performance) Optimize String#compare in case of ASCII only. (#7352, thanks @r00ster91)
• Add methods for human-readable formatting of numbers: Number#format, Number#humanize, and Int#humanize_bytes. (#6314, thanks @straight-shoota)
• Add String#rchop? and String#lchop?. (#7328, thanks @j8r)
• Add options argument to String#camelcase and String#underscore. (#7374, thanks @r00ster91)
• Add docs to Unicode::CaseOptions. (#7513, thanks @r00ster91)
• Improve specs and docs for String#each_line and IO#each_line. (#7419, thanks @straight-shoota)

Collections

• (breaking-change) Let Array#sort only use <=>, and let <=> return nil for partial comparability. (#6611, thanks @asterite)
• (breaking-change) Drop Iterator#rewind. Implement #cycle by storing elements in an array. (#7440, thanks @asterite)
• (performance) Add Enumerable#each_cons support for Deque as a reuse buffer. (#7233, thanks @yxhuvud)
• (performance) Change Range#bsearch / 2 to >> 1 for faster performance. (#7531, thanks @Fryguy)
• Fix Slice#clone for non-primitive types and deep copy. (#7591, thanks @straight-shoota)
• Move Indexable#zip and Indexable#zip? to Enumerable and make it work with any number of Indexable or Iterable or Iterator. (#7453, thanks @asterite)
• Add Slice#[](Range). (#7439, thanks @asterite)
• Add nillable range fetching #[]?(Range) to Array and String. (#7338, thanks @j8r)
• Add Set#add?. (#7495, thanks @Sija)
• Improve documentation of Hash regarding ordering of items. (#7594, thanks @straight-shoota)

Serialization

• (breaking-change) Change return type of YAML#libyaml_version to SemanticVersion. (#7555, thanks @asterite)
• Fix support for libxml2 2.9.9. (#7477, thanks @asterite)
• Fix support for libyaml 0.2.2. (#7555, thanks @asterite)
• Add BigDecimal.from_yaml. (#7398, thanks @Sija)

Time

• (breaking-change) Rename Time constructors. Deprecate Time.now to encourage usage Time.utc or Time.local (#5346, #7586, thanks @straight-shoota)
• (breaking-change) Rename Time#add_span to Time#shift for changing a time instance by calendar units and handle other units. (#6598, thanks @straight-shoota)
• (breaking-change) Change Time#date to return a Tuple of {year, month, day}. Use Time#at_beginning_of_day if a Time instance is wanted. (#5822, thanks @straight-shoota)
• Fix Windows monotonic time bug. (#7377, thanks @domgetter)
• Refactor Time methods. (#6581, thanks @straight-shoota)

Files

• (breaking-change) Remove IO#flush_on_newline and only sync on STDOUT/STDIN/STDERR when they are TTY devices. (#7470, thanks @asterite)
• Add Path type. (#5635, thanks @straight-shoota)

Networking

• (breaking-change) Move HTTP::Multipart to MIME::Multipart. (#7085, thanks @m1lt0n)

• (breaking-change) Stop parsing JSON in OAuth2 errors. (#7467, thanks @asterite)

• (breaking-change) Fix RequestProcessor connection reuse logic. (#7055, thanks @straight-shoota)

• (breaking-change) Replace HTTP.default_status_message_for(Int) with HTTP::Status.new(Int).description. (#7247, thanks @dwightwatson)

• (breaking-change) Fix issues in URI implementation. URI#opaque method is merged into URI#path, which no longer returns Nil. #parse/#to_s normalization and default port handling has changed. (#6323, thanks @straight-shoota)

• Fix write buffering in OpenSSL sockets. (#7460, thanks @carlhoerberg)

• Fix leaks in HTTP::Server #bind_* and specs. (#7197, thanks @straight-shoota)

• Add HTTP::Request#remote_address. (#7610, thanks @asterite)

• Add HTTP::Status and Response#status. (#7247, #7682, thanks @dwightwatson, and @bcardiff)

• Add support for OAuth 2.0 resource owner password credentials grant type. (#7424, thanks @Blacksmoke16)

• Add support for IIS date format in cookies. (#7405, thanks @Sija)

• Allow calls to IO::Syscall#wait_readable and IO::Syscall#wait_writable. (#7366, thanks @stakach)

• Fix spec of HTTP::Client to not write server response after timeout. (#7402, thanks @asterite)

• Fix spec of TCP::Server for musl. (#7484, thanks @straight-shoota)

Crypto

• (breaking-change) Use OpenSSL::Algorithm instead of symbols for digest/hexdigest. Expose LibCrypt's PKCS5_PBKDF2_HMAC. (#7264, thanks @mniak)

Concurrency

• Add multi-threading ready GC when compiling with -D preview_mt. (#7546, thanks @bcardiff, @waj, and @ysbaddaden)
• Ship patched bdw-gc for multi-threading support. (#7622, thanks @bcardiff, and @ysbaddaden)
• Refactor to extract Fiber::StackPool from Fiber. (#7417, thanks @ysbaddaden)
• Refactor IO::Syscall as IO::Evented. (#7505, thanks @ysbaddaden)

System

• Add command and args to execvp error message. (#7511, thanks @straight-shoota)
• Refactor signals handling in a separate fiber. (#7469, thanks @asterite)

Spec

• Improve how running specs are cancelled upon CTRL+C. (#7426, thanks @asterite)
• Allow pending and it to accept constants. (#7646, thanks @straight-shoota)

Compiler

• (performance) Avoid fork and spawn when --threads=1. (#7397, thanks @asterite)
• Fix exception type thrown on missing require. (#7386, thanks @asterite)
• Fix ICE when assigning a constant inside a multi-assign. (#7468, thanks @asterite)
• Fix parsing and behaviour of ->foo.[] and other operators . (#7334, thanks @asterite)
• Fix parsing bug in asm with 3 colons and a variable. (#7627, thanks @r00ster91)
• Opt-in detection of calls to @[Deprecated] methods. (#7596, #7626, #7661, thanks @bcardiff)
• Add CRYSTAL_LIBRARY_PATH for lookup static libraries. (#7562, thanks @bcardiff)
• Improve error messages by adding the scope (and with ... yield scope, if any) on undefined method error. (#7384, thanks @asterite)
• Suggest next when trying to break from captured block . (#7406, thanks @r00ster91)
• Add detection of linux environment in compiler config. (#7479, thanks @straight-shoota)
• Pending leftovers to support // and &-ops in multiple places. (#7628, thanks @bcardiff)
• Refactor Crystal::Config.version to use read_file macro. (#7081, thanks @Sija)
• Rewrite macro spec without executing a shell command. (#6962, thanks @asterite)
• Fix typo in internals. (#7592, thanks @toshokan)

Language semantics

• Fix issues with as, as? and unions and empty types. (#7475, thanks @asterite)
• Fix method lookup when restrictions of instantiated and non-instantiated generic types are used. (#7537, thanks @bew)
• Fix method lookup when free vars and explicit types are used. (#7536, #7580, thanks @bew)
• When declaring a protected initialize, define a protected new. (#7510, thanks @asterite)
• Fix named args type matching. (#7529, thanks @asterite)
• Merge procs with the same arguments type and Nil | T return type to Nil return type. (#7527, thanks @asterite)
• Fix passing recursive alias to proc. (#7568, thanks @asterite)

Tools

• Suggest the user to run the formatter in travis.yml. (#7138, thanks @KCErb)

Formatter

• Fix formatting of 1\n.as(Int32). (#7347, thanks @asterite)
• Fix formatting of nested array elements. (#7450, thanks @makenowjust)
• Fix formatting of comments and enums. (#7605, thanks @asterite)
• Fix CLI handling of absolute paths input. (#7560, thanks @RX14)

Doc generator

• Don't include private constants. (#7575, thanks @r00ster91)
• Include Crystal built-in constants. (#7623, thanks @bcardiff)
• Add compile-time flag to docs generator. (#6668, #7438, thanks @straight-shoota)
• Display deprecated label when @[Deprecated] is used. (#7653, thanks @bcardiff)

Playground

• Change the font-weight used for better readability. (#7552, thanks @Maroo-b)

Others

• CI improvements and housekeeping. (#7359, #7381, #7388, #7387, #7390, #7622, thanks @bcardiff)
• Smoke test linux 64 bits package using docker image recent build. (#7389, thanks @bcardiff)
• Mention git pre-commit hook in CONTRIBUTING.md. (#7617, thanks @straight-shoota)
• Fix misspellings throughout the codebase. (#7361, thanks @Sija)
• Use chars instead of strings throughout the codebase. (#6237, thanks @r00ster91)
• Fix GC finalization warning in Thread specs. (#7403, thanks @asterite)
• Remove generated docs from linux packages. (#7519, thanks @straight-shoota)