Update NEWS for Ruby 2.8.0 (tentative; to be 3.0.0)

1 files changed, 2 insertions, 799 deletions

diff --git a/NEWS b/NEWS
index 4ff6cf09dc..15f5f14eb8 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,6 @@
 # -*- rdoc -*-
 
-= NEWS for Ruby 2.7.0
+= NEWS for Ruby 2.8.0 (tentative; to be 3.0.0)
 
 This document is a list of user visible feature changes made between
 releases except for bug fixes.
@@ -10,819 +10,22 @@ information is supplied with.  For a full list of changes with all
 sufficient information, see the ChangeLog file or Redmine
 (e.g. <tt>https://bugs.ruby-lang.org/issues/$FEATURE_OR_BUG_NUMBER</tt>).
 
-== Changes since the 2.6.0 release
+== Changes since the 2.7.0 release
 
 === Language changes
 
-==== Pattern matching
-
-* Pattern matching is introduced as an experimental feature. [Feature #14912]
-
-    case [0, [1, 2, 3]]
-    in [a, [b, *c]]
-      p a #=> 0
-      p b #=> 1
-      p c #=> [2, 3]
-    end
-
-    case {a: 0, b: 1}
-    in {a: 0, x: 1}
-      :unreachable
-    in {a: 0, b: var}
-      p var #=> 1
-    end
-
-    case -1
-    in 0 then :unreachable
-    in 1 then :unreachable
-    end #=> NoMatchingPatternError
-
-    json = <<END
-    {
-      "name": "Alice",
-      "age": 30,
-      "children": [{ "name": "Bob", "age": 2 }]
-    }
-    END
-
-    JSON.parse(json, symbolize_names: true) in {name: "Alice", children: [{name: name, age: age}]}
-
-    p name #=> "Bob"
-    p age  #=> 2
-
-    JSON.parse(json, symbolize_names: true) in {name: "Alice", children: [{name: "Charlie", age: age}]}
-    #=> NoMatchingPatternError
-
-* See the following slides for more details:
-  * https://speakerdeck.com/k_tsj/pattern-matching-new-feature-in-ruby-2-dot-7
-  * Note that the slides are slightly obsolete.
-
-* The warning against pattern matching can be suppressed with
-  {-W:no-experimental option}[#label-Warning+option].
-
-==== The spec of keyword arguments is changed towards 3.0
-
-* Automatic conversion of keyword arguments and positional arguments is
-  deprecated, and conversion will be removed in Ruby 3.  [Feature #14183]
-
-  * When a method call passes a Hash at the last argument, and when it
-    passes no keywords, and when the called method accepts keywords,
-    a warning is emitted.  To continue treating the hash as keywords,
-    add a double splat operator to avoid the warning and ensure
-    correct behavior in Ruby 3.
-
-      def foo(key: 42); end; foo({key: 42})   # warned
-      def foo(**kw);    end; foo({key: 42})   # warned
-      def foo(key: 42); end; foo(**{key: 42}) # OK
-      def foo(**kw);    end; foo(**{key: 42}) # OK
-
-  * When a method call passes keywords to a method that accepts keywords,
-    but it does not pass enough required positional arguments, the
-    keywords are treated as a final required positional argument, and a
-    warning is emitted.  Pass the argument as a hash instead of keywords
-    to avoid the warning and ensure correct behavior in Ruby 3.
-
-      def foo(h, **kw); end; foo(key: 42)      # warned
-      def foo(h, key: 42); end; foo(key: 42)   # warned
-      def foo(h, **kw); end; foo({key: 42})    # OK
-      def foo(h, key: 42); end; foo({key: 42}) # OK
-
-  * When a method accepts specific keywords but not a keyword splat, and
-    a hash or keywords splat is passed to the method that includes both
-    Symbol and non-Symbol keys, the hash will continue to be split, and
-    a warning will be emitted.  You will need to update the calling code
-    to pass separate hashes to ensure correct behavior in Ruby 3.
-
-      def foo(h={}, key: 42); end; foo("key" => 43, key: 42)   # warned
-      def foo(h={}, key: 42); end; foo({"key" => 43, key: 42}) # warned
-      def foo(h={}, key: 42); end; foo({"key" => 43}, key: 42) # OK
-
-  * If a method does not accept keywords, and is called with keywords,
-    the keywords are still treated as a positional hash, with no warning.
-    This behavior will continue to work in Ruby 3.
-
-      def foo(opt={});  end; foo( key: 42 )   # OK
-
-* Non-symbols are allowed as keyword argument keys if the method accepts
-  arbitrary keywords. [Feature #14183]
-
-  * Non-Symbol keys in a keyword arguments hash were prohibited in 2.6.0,
-    but are now allowed again.  [Bug #15658]
-
-      def foo(**kw); p kw; end; foo("str" => 1) #=> {"str"=>1}
-
-* <code>**nil</code> is allowed in method definitions to explicitly mark
-  that the method accepts no keywords. Calling such a method with keywords
-  will result in an ArgumentError. [Feature #14183]
-
-    def foo(h, **nil); end; foo(key: 1)       # ArgumentError
-    def foo(h, **nil); end; foo(**{key: 1})   # ArgumentError
-    def foo(h, **nil); end; foo("str" => 1)   # ArgumentError
-    def foo(h, **nil); end; foo({key: 1})     # OK
-    def foo(h, **nil); end; foo({"str" => 1}) # OK
-
-* Passing an empty keyword splat to a method that does not accept keywords
-  no longer passes an empty hash, unless the empty hash is necessary for
-  a required parameter, in which case a warning will be emitted.  Remove
-  the double splat to continue passing a positional hash.  [Feature #14183]
-
-    h = {}; def foo(*a) a end; foo(**h) # []
-    h = {}; def foo(a) a end; foo(**h)  # {} and warning
-    h = {}; def foo(*a) a end; foo(h)   # [{}]
-    h = {}; def foo(a) a end; foo(h)    # {}
-
-* Above warnings can be suppressed also with {-W:no-deprecated option}[#label-Warning+option].
-
-==== Numbered parameters
-
-* Numbered parameters as default block parameters are introduced.
-  [Feature #4475]
-
-    [1, 2, 10].map { _1.to_s(16) }    #=> ["1", "2", "a"]
-    [[1, 2], [3, 4]].map { _1 + _2 }  #=> [3, 7]
-
-  You can still define a local variable named +_1+ and so on,
-  and that is honored when present, but renders a warning.
-
-    _1 = 0            #=> warning: `_1' is reserved for numbered parameter; consider another name
-    [1].each { p _1 } # prints 0 instead of 1
-
-==== proc/lambda without block is deprecated
-
-* Proc.new and Kernel#proc with no block in a method called with a block will
-  now display a warning.
-
-    def foo
-      proc
-    end
-    foo { puts "Hello" } #=> warning: Capturing the given block using Kernel#proc is deprecated; use `&block` instead
-
-  This warning can be suppressed with {-W:no-deprecated option}[#label-Warning+option].
-
-* Kernel#lambda with no block in a method called with a block raises an exception.
-
-    def bar
-      lambda
-    end
-    bar { puts "Hello" } #=> tried to create Proc object without a block (ArgumentError)
-
-==== Other miscellaneous changes
-
-* A beginless range is experimentally introduced.  It might be useful
-  in +case+, new call-sequence of the <code>Comparable#clamp</code>,
-  constants and DSLs.  [Feature #14799]
-
-     ary[..3]  # identical to ary[0..3]
-
-     case RUBY_VERSION
-     when ..."2.4" then puts "EOL"
-     # ...
-     end
-
-     age.clamp(..100)
-
-     where(sales: ..100)
-
-* Setting <code>$;</code> to a non-nil value will now display a warning. [Feature #14240]
-  This includes the usage in String#split.
-  This warning can be suppressed with {-W:no-deprecated option}[#label-Warning+option].
-
-* Setting <code>$,</code> to a non-nil value will now display a warning. [Feature #14240]
-  This include the usage in Array#join.
-  This warning can be suppressed with {-W:no-deprecated option}[#label-Warning+option].
-
-* Quoted here-document identifiers must end within the same line.
-
-     <<"EOS
-     " # This had been warned since 2.4; Now it raises a SyntaxError
-     EOS
-
-* The flip-flop syntax deprecation is reverted. [Feature #5400]
-
-* Comment lines can be placed between fluent dot now.
-
-    foo
-      # .bar
-      .baz # => foo.baz
-
-* Calling a private method with a literal +self+ as the receiver
-  is now allowed. [Feature #11297] [Feature #16123]
-
-* Modifier rescue now operates the same for multiple assignment as single
-  assignment. [Bug #8279]
-
-    a, b = raise rescue [1, 2]
-    # Previously parsed as: (a, b = raise) rescue [1, 2]
-    # Now parsed as:         a, b = (raise rescue [1, 2])
-
-* +yield+ in singleton class syntax will now display a warning. This behavior
-  will soon be deprecated. [Feature #15575].
-
-   def foo
-     class << Object.new
-       yield #=> warning: `yield' in class syntax will not be supported from Ruby 3.0. [Feature #15575]
-     end
-   end
-   foo { p :ok }
-
-  This warning can be suppressed with {-W:no-deprecated option}[#label-Warning+option].
-
-* Argument forwarding by <code>(...)</code> is introduced. [Feature #16253]
-
-    def foo(...)
-      bar(...)
-    end
-
-  All arguments to +foo+ are forwarded to +bar+, including keyword and
-  block arguments.
-  Note that the parentheses are mandatory.  <code>bar ...</code> is parsed
-  as an endless range.
-
-* Access and setting of <code>$SAFE</code> will now always display a warning.
-  <code>$SAFE</code> will become a normal global variable in Ruby 3.0.
-  [Feature #16131]
-
-* <code>Object#{taint,untaint,trust,untrust}</code> and related functions in the C-API
-  no longer have an effect (all objects are always considered untainted), and will now
-  display a warning in verbose mode. This warning will be disabled even in non-verbose mode in
-  Ruby 3.0, and the methods and C functions will be removed in Ruby 3.2. [Feature #16131]
-
-* Refinements take place at Object#method and Module#instance_method. [Feature #15373]
-
 === Command line options
 
-==== Warning option
-
-The +-W+ option has been extended with a following +:+, to manage categorized
-warnings.  [Feature #16345] [Feature #16420]
-
-* To suppress deprecation warnings:
-
-    $ ruby -e '$; = ""'
-    -e:1: warning: `$;' is deprecated
-
-    $ ruby -W:no-deprecated -e '$; = //'
-
-* It works with the +RUBYOPT+ environment variable:
-
-    $ RUBYOPT=-W:no-deprecated ruby -e '$; = //'
-
-* To suppress experimental feature warnings:
-
-    $ ruby -e '0 in a'
-    -e:1: warning: Pattern matching is experimental, and the behavior may change in future versions of Ruby!
-
-    $ ruby -W:no-experimental -e '0 in a'
-
-* To suppress both by using +RUBYOPT+, set space separated values:
-
-    $ RUBYOPT='-W:no-deprecated -W:no-experimental' ruby -e '($; = "") in a'
-
-See also Warning in {Core classes updates}[#label-Core+classes+updates+-28outstanding+ones+only-29].
-
 === Core classes updates (outstanding ones only)
 
-Array::
-
-  New methods::
-
-    * Added Array#intersection. [Feature #16155]
-
-    * Added Array#minmax, with a faster implementation than Enumerable#minmax. [Bug #15929]
-
-Comparable::
-
-  Modified method::
-
-    * Comparable#clamp now accepts a Range argument. [Feature #14784]
-
-        -1.clamp(0..2) #=> 0
-         1.clamp(0..2) #=> 1
-         3.clamp(0..2) #=> 2
-        # With beginless and endless ranges:
-        -1.clamp(0..)  #=> 0
-         3.clamp(..2)  #=> 2
-
-
-Complex::
-
-  New method::
-
-    * Added Complex#<=>.
-      So <code>0 <=> 0i</code> will not raise NoMethodError. [Bug #15857]
-
-Dir::
-
-  Modified methods::
-
-    * Dir.glob and Dir.[] no longer allow NUL-separated glob pattern.
-      Use Array instead.  [Feature #14643]
-
-Encoding::
-
-  New encoding::
-
-    * Added new encoding CESU-8. [Feature #15931]
-
-Enumerable::
-
-  New methods::
-
-    * Added Enumerable#filter_map.  [Feature #15323]
-
-        [1, 2, 3].filter_map {|x| x.odd? ? x.to_s : nil } #=> ["1", "3"]
-
-    * Added Enumerable#tally.  [Feature #11076]
-
-        ["A", "B", "C", "B", "A"].tally #=> {"A"=>2, "B"=>2, "C"=>1}
-
-Enumerator::
-
-  New methods::
-
-    * Added Enumerator.produce to generate an Enumerator from any custom
-      data transformation.  [Feature #14781]
-
-        require "date"
-        dates = Enumerator.produce(Date.today, &:succ) #=> infinite sequence of dates
-        dates.detect(&:tuesday?) #=> next Tuesday
-
-    * Added Enumerator::Lazy#eager that generates a non-lazy enumerator
-      from a lazy enumerator.  [Feature #15901]
-
-        a = %w(foo bar baz)
-        e = a.lazy.map {|x| x.upcase }.map {|x| x + "!" }.eager
-        p e.class               #=> Enumerator
-        p e.map {|x| x + "?" }  #=> ["FOO!?", "BAR!?", "BAZ!?"]
-
-    * Added Enumerator::Yielder#to_proc so that a Yielder object
-      can be directly passed to another method as a block
-      argument.  [Feature #15618]
-
-Fiber::
-
-  New method::
-
-    * Added Fiber#raise that behaves like Fiber#resume but raises an
-      exception on the resumed fiber.  [Feature #10344]
-
-File::
-
-  Modified method::
-
-    * File.extname now returns a dot string for names ending with a dot on
-      non-Windows platforms.  [Bug #15267]
-
-          File.extname("foo.") #=> "."
-
-FrozenError::
-
-  New method::
-
-    * Added FrozenError#receiver to return the frozen object on which
-      modification was attempted.  To set this object when raising
-      FrozenError in Ruby code, FrozenError.new accepts a +:receiver+
-      option.  [Feature #15751]
-
-GC::
-
-  New method::
-
-    * Added GC.compact method for compacting the heap.
-      This function compacts live objects in the heap so that fewer pages may
-      be used, and the heap may be more CoW (copy-on-write) friendly. [Feature #15626]
-
-      Details on the algorithm and caveats can be found here:
-      https://bugs.ruby-lang.org/issues/15626
-
-IO::
-
-  New method::
-
-    * Added IO#set_encoding_by_bom to check the BOM and set the external
-      encoding.  [Bug #15210]
-
-Integer::
-
-  Modified method::
-
-    * Integer#[] now supports range operations.  [Feature #8842]
-
-         0b01001101[2, 4]  #=> 0b0011
-         0b01001100[2..5]  #=> 0b0011
-         0b01001100[2...6] #=> 0b0011
-         #   ^^^^
-
-Method::
-
-  Modified method::
-
-    * Method#inspect shows more information. [Feature #14145]
-
-Module::
-
-  New methods::
-
-    * Added Module#const_source_location to retrieve the location where a
-      constant is defined.  [Feature #10771]
-
-    * Added Module#ruby2_keywords for marking a method as passing keyword
-      arguments through a regular argument splat, useful when delegating
-      all arguments to another method in a way that can be backwards
-      compatible with older Ruby versions.  [Bug #16154]
-
-  Modified methods::
-
-    * Module#autoload? now takes an +inherit+ optional argument, like
-      Module#const_defined?.  [Feature #15777]
-
-    * Module#name now always returns a frozen String. The returned String is
-      always the same for a given Module. This change is
-      experimental. [Feature #16150]
-
-NilClass / TrueClass / FalseClass::
-
-  Modified methods::
-
-    * NilClass#to_s, TrueClass#to_s, and FalseClass#to_s now always return a
-      frozen String. The returned String is always the same for each of these
-      values. This change is experimental. [Feature #16150]
-
-ObjectSpace::WeakMap::
-
-  Modified method::
-
-    * ObjectSpace::WeakMap#[]= now accepts special objects as either key or
-      values.  [Feature #16035]
-
-Proc::
-
-  New method::
-
-    * Added Proc#ruby2_keywords for marking the proc as passing keyword
-      arguments through a regular argument splat, useful when delegating
-      all arguments to another method or proc in a way that can be backwards
-      compatible with older Ruby versions.  [Feature #16404]
-
-Range::
-
-  New method::
-
-    * Added Range#minmax, with a faster implementation than Enumerable#minmax.
-      It returns a maximum that now corresponds to Range#max. [Bug #15807]
-
-  Modified method::
-
-    * Range#=== now uses Range#cover? for String arguments, too (in Ruby 2.6, it was
-      changed from Range#include? for all types except strings). [Bug #15449]
-
-
-RubyVM::
-
-  Removed method::
-
-    * +RubyVM.resolve_feature_path+ moved to
-      <code>$LOAD_PATH.resolve_feature_path</code>.  [Feature #15903] [Feature #15230]
-
-String::
-
-  Unicode::
-
-    * Update Unicode version and Emoji version from 11.0.0 to
-      12.0.0.  [Feature #15321]
-
-    * Update Unicode version to 12.1.0, adding support for
-      U+32FF SQUARE ERA NAME REIWA.  [Feature #15195]
-
-    * Update Unicode Emoji version to 12.1. [Feature #16272]
-
-Symbol::
-
-  New methods::
-
-    * Added Symbol#start_with? and Symbol#end_with? methods.  [Feature #16348]
-
-Time::
-
-  New methods::
-
-    * Added Time#ceil method.  [Feature #15772]
-
-    * Added Time#floor method.  [Feature #15653]
-
-  Modified method::
-
-    * Time#inspect is separated from Time#to_s and it shows
-      the time's sub second.  [Feature #15958]
-
-UnboundMethod::
-
-  New method::
-
-    * Added UnboundMethod#bind_call method.  [Feature #15955]
-
-      <code>umethod.bind_call(obj, ...)</code> is semantically equivalent
-      to <code>umethod.bind(obj).call(...)</code>.  This idiom is used in
-      some libraries to call a method that is overridden.  The added
-      method does the same without allocation of an intermediate Method
-      object.
-
-          class Foo
-            def add_1(x)
-              x + 1
-            end
-          end
-          class Bar < Foo
-            def add_1(x) # override
-              x + 2
-            end
-          end
-
-          obj = Bar.new
-          p obj.add_1(1) #=> 3
-          p Foo.instance_method(:add_1).bind(obj).call(1) #=> 2
-          p Foo.instance_method(:add_1).bind_call(obj, 1) #=> 2
-
-Warning::
-
-  New methods::
-
-    * Added Warning.[] and Warning.[]= to manage emitting/suppressing
-      some categories of warnings.  [Feature #16345] [Feature #16420]
-
-$LOAD_PATH::
-
-  New method::
-
-    * Added <code>$LOAD_PATH.resolve_feature_path</code>.  [Feature #15903] [Feature #15230]
-
 === Stdlib updates (outstanding ones only)
 
-Bundler::
-
-  * Upgrade to Bundler 2.1.2.
-    See https://github.com/bundler/bundler/releases/tag/v2.1.2
-
-CGI::
-
-  * CGI.escapeHTML becomes 2~5x faster when there is at least one escaped character.
-    See https://github.com/ruby/ruby/pull/2226
-
-CSV::
-
-  * Upgrade to 3.1.2.
-    See https://github.com/ruby/csv/blob/master/NEWS.md.
-
-Date::
-
-  * Date.jisx0301, Date#jisx0301, and Date.parse support the new Japanese
-    era.  [Feature #15742]
-
-Delegator::
-
-  * Object#DelegateClass accepts a block and module_evals it in the context
-    of the returned class, similar to Class.new and Struct.new.
-
-ERB::
-
-  * Prohibit marshaling ERB instance.
-
-IRB::
-
-  * Introduce syntax highlighting inspired by the Pry gem to Binding#irb
-    source lines, REPL input, and inspect output of some core-class objects.
-
-  * Introduce multiline editing mode provided by Reline.
-
-  * Show documentation when completion.
-
-  * Enable auto indent and save/load history by default.
-
-JSON::
-
-  * Upgrade to 2.3.0.
-
-Net::FTP::
-
-  * Add Net::FTP#features to check available features, and Net::FTP#option to
-    enable/disable each of them.  [Feature #15964]
-
-Net::HTTP::
-
-  * Add +ipaddr+ optional parameter to Net::HTTP#start to replace the address for
-    the TCP/IP connection. [Feature #5180]
-
-Net::IMAP::
-
-  * Add Server Name Indication (SNI) support.  [Feature #15594]
-
-open-uri::
-
-  * Warn open-uri's "open" method at Kernel.
-    Use URI.open instead.  [Misc #15893]
-
-  * The default charset of "text/*" media type is UTF-8 instead of
-    ISO-8859-1.  [Bug #15933]
-
-OptionParser::
-
-  * Now show "Did you mean?" for unknown options.  [Feature #16256]
-
-    test.rb:
-
-      require "optparse"
-      OptionParser.new do |opts|
-        opts.on("-f", "--foo", "foo") {|v| }
-        opts.on("-b", "--bar", "bar") {|v| }
-        opts.on("-c", "--baz", "baz") {|v| }
-      end.parse!
-
-    example:
-
-      $ ruby test.rb --baa
-      Traceback (most recent call last):
-      test.rb:7:in `<main>': invalid option: --baa (OptionParser::InvalidOption)
-      Did you mean?  baz
-                     bar
-
-Pathname::
-
-  * Pathname.glob now delegates 3 arguments to Dir.glob
-    to accept +base+ keyword. [Feature #14405]
-
-Racc::
-
-  * Merge 1.4.15 from upstream repository and added cli of racc.
-
-Reline::
-
-  * New stdlib that is compatible with the readline stdlib but is
-    implemented in pure Ruby. It also provides a multiline editing mode.
-
-REXML::
-
-  * Upgrade to 3.2.3.
-    See https://github.com/ruby/rexml/blob/master/NEWS.md.
-
-RSS::
-
-  * Upgrade to RSS 0.2.8.
-    See https://github.com/ruby/rss/blob/master/NEWS.md.
-
-RubyGems::
-
-  * Upgrade to RubyGems 3.1.2.
-    * https://github.com/rubygems/rubygems/releases/tag/v3.1.0
-    * https://github.com/rubygems/rubygems/releases/tag/v3.1.1
-    * https://github.com/rubygems/rubygems/releases/tag/v3.1.2
-
-StringScanner::
-
-  * Upgrade to 1.0.3.
-    See https://github.com/ruby/strscan/blob/master/NEWS.md.
-
 === Compatibility issues (excluding feature bug fixes)
 
-* The following libraries are no longer bundled gems.
-  Install corresponding gems to use these features.
-  * CMath (cmath gem)
-  * Scanf (scanf gem)
-  * Shell (shell gem)
-  * Synchronizer (sync gem)
-  * ThreadsWait (thwait gem)
-  * E2MM (e2mmap gem)
-
-Proc::
-  * The Proc#to_s format was changed. [Feature #16101]
-
-Range::
-  * Range#minmax used to iterate on the range to determine the maximum.
-    It now uses the same algorithm as Range#max. In rare cases (e.g.
-    ranges of Floats or Strings), this may yield different results. [Bug #15807]
-
 === Stdlib compatibility issues (excluding feature bug fixes)
 
-* Promote stdlib to default gems
-  * The following default gems were published on rubygems.org
-    * benchmark
-    * cgi
-    * delegate
-    * getoptlong
-    * net-pop
-    * net-smtp
-    * open3
-    * pstore
-    * readline
-    * readline-ext
-    * singleton
-  * The following default gems were only promoted at ruby-core,
-    but not yet published on rubygems.org.
-    * monitor
-    * observer
-    * timeout
-    * tracer
-    * uri
-    * yaml
-* The <tt>did_you_mean</tt> gem has been promoted up to a default gem from a bundled gem
-
-pathname::
-
-  * Kernel#Pathname when called with a Pathname argument now returns
-    the argument instead of creating a new Pathname. This is more
-    similar to other Kernel methods, but can break code that modifies
-    the return value and expects the argument not to be modified.
-
-profile.rb, Profiler__::
-
-  * Removed from standard library. It was unmaintained since Ruby 2.0.0.
-
 === C API updates
 
-* Many <code>*_kw</code> functions have been added for setting whether
-  the final argument being passed should be treated as keywords. You
-  may need to switch to these functions to avoid keyword argument
-  separation warnings, and to ensure correct behavior in Ruby 3.
-
-* The <code>:</code> character in rb_scan_args format string is now
-  treated as keyword arguments. Passing a positional hash instead of
-  keyword arguments will emit a deprecation warning.
-
-* C API declarations with +ANYARGS+ are changed not to use +ANYARGS+.
-  See https://github.com/ruby/ruby/pull/2404
-
 === Implementation improvements
 
-Fiber::
-
-  * Allow selecting different coroutine implementations by using
-    +--with-coroutine=+, e.g.
-
-         $ ./configure --with-coroutine=ucontext
-         $ ./configure --with-coroutine=copy
-
-  * Replace previous stack cache with fiber pool cache. The fiber pool
-    allocates many stacks in a single memory region. Stack allocation
-    becomes O(log N) and fiber creation is amortized O(1). Around 10x
-    performance improvement was measured in micro-benchmarks.
-    https://github.com/ruby/ruby/pull/2224
-
-File::
-  * File.realpath now uses realpath(3) on many platforms, which can
-    significantly improve performance. [Feature #15797]
-
-Hash::
-  * Change data structure of small Hash objects. [Feature #15602]
-
-Monitor::
-  * Monitor class is written in C-extension. [Feature #16255]
-
-Thread::
-
-  * VM stack memory allocation is now combined with native thread stack,
-    improving thread allocation performance and reducing allocation related
-    failures. Around 10x performance improvement was measured in micro-benchmarks.
-
-JIT::
-
-  * JIT-ed code is recompiled to less-optimized code when an optimization assumption is invalidated.
-
-  * Method inlining is performed when a method is considered as pure.
-    This optimization is still experimental and many methods are NOT considered as pure yet.
-
-  * The default value of +--jit-max-cache+ is changed from 1,000 to 100.
-
-  * The default value of +--jit-min-calls+ is changed from 5 to 10,000.
-
-RubyVM::
-
-  * Per-call-site method cache, which has been there since around 1.9, was
-    improved: cache hit rate raised from 89% to 94%.
-    See https://github.com/ruby/ruby/pull/2583
-
-RubyVM::InstructionSequence::
-
-  * RubyVM::InstructionSequence#to_binary method generates compiled binary.
-    The binary size is reduced. [Feature #16163]
-
 === Miscellaneous changes
-
-* Support for IA64 architecture has been removed. Hardware for testing was
-  difficult to find, native fiber code is difficult to implement, and it added
-  non-trivial complexity to the interpreter. [Feature #15894]
-
-* Require compilers to support C99. [Misc #15347]
-
-  * Details of our dialect: https://bugs.ruby-lang.org/projects/ruby-trunk/wiki/C99
-
-* Ruby's upstream repository is changed from Subversion to Git.
-
-  * https://git.ruby-lang.org/ruby.git
-
-  * RUBY_REVISION class is changed from Integer to String.
-
-  * RUBY_DESCRIPTION includes Git revision instead of Subversion's one.
-
-* Support built-in methods in Ruby with the <code>_\_builtin_</code> syntax. [Feature #16254]
-
-  Some methods are defined in *.rb (such as trace_point.rb).
-  For example, it is easy to define a method which accepts keyword arguments.