ruby/NEWS

# -*- rdoc -*-

= NEWS for Ruby 2.5.0

This document is a list of user visible feature changes made between
releases except for bug fixes.

Note that each entry is kept so brief that no reason behind or
reference 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 2.4.0 release

=== Language changes

* Top-level constant look-up is removed.  [Feature #11547]

* rescue/else/ensure are allowed inside do/end blocks.  [Feature #12906]

* refinements take place in string interpolations.  [Feature #13812]

=== Core classes updates (outstanding ones only)

* Array

  * Array#append  [Feature #12746]
  * Array#prepend  [Feature #12746]

* Data

  * Now deprecated [Feature #3072]

* Dir

  * Dir.glob provides new optional keyword argument, :base.
    [Feature #13056]
  * Dir.children  [Feature #11302]
  * Dir.each_child  [Feature #11302]

* File

  * :newline option to File.open implies text mode now.  [Bug #13350]
  * File#path now raises an IOError for files opened with
    File::Constants::TMPFILE option. [Feature #13568]
  * File.stat, File.exist?, and other rb_stat()-using methods release GVL
    [Bug #13941]
  * File.rename releases GVL [Feature #13951]
  * Add File.lutime  [Feature #4052]

* Hash

  * Hash#transform_keys  [Feature #13583]
  * Hash#transform_keys!  [Feature #13583]
  * Hash#slice  [Feature #8499]

* IO

  * IO#pread  [Feature #4532]
  * IO#pwrite  [Feature #4532]
  * IO#copy_stream tries copy offload with copy_file_range(2) [Feature #13867]
  * IO#write accepts multiple arguments  [Feature #9323]

* IOError

  * exception message "stream closed" is changed  [Bug #13405]

* Integer

  * Integer.sqrt  [Feature #13219]
  * Integer#step does no longer rescue exceptions when given
    a step value which cannot be compared with #> to 0. [Feature #7688]
  * Integer#{round,floor,ceil,truncate} now always return an Integer.
    [Bug #13420]
  * Integer#pow now has an optional modulo argument for calculating modular
    exponentiation.  [Feature #12508] [Feature #11003]

* Kernel

  * Kernel#yield_self  [Feature #6721]
  * Kernel#pp [Feature #14123]

* Module
  * Module#attr, attr_accessor, attr_reader, attr_writer are now public [#14132]
  * Module#define_method, alias_method, undef_method, remove_method are now public [#14133]

* Numeric

  * Numerical comparison operators (<,<=,>=,>) no longer rescue exceptions
    of #coerce. Return nil in #coerce if the coercion is impossible.
    [Feature #7688]

* Process

  * Precision of Process.times is improved if getrusage(2) exists. [Feature #11952]

* Range
  * Range#initialize no longer rescue exceptions when comparing begin and
    end with #<=> and raise a "bad value for range" ArgumentError
    but instead let the exception from the #<=> call go through.
    [Feature #7688]

* Regexp
  * Update to Onigmo 6.1.3-669ac9997619954c298da971fcfacccf36909d05.
    * Support absent operator https://github.com/k-takata/Onigmo/issues/82

* String

  * String#-@ deduplicates unfrozen strings.  Already-frozen
    strings remain unchanged for compatibility.  [Feature #13077]
  * -"literal" (String#-@) optimized to return the same object
    (same as "literal".freeze in Ruby 2.1+) [Feature #13295]
  * String#{casecmp,casecmp?} now return nil for non-string arguments
    instead of raising a TypeError. [Bug #13312]
  * String#delete_prefix is added to remove prefix [Feature #12694]
  * String#delete_prefix! is added to remove prefix destructively [Feature #12694]
  * String#delete_suffix is added to remove suffix [Feature #13665]
  * String#delete_suffix! is added to remove suffix destructively [Feature #13665]
  * String#each_grapheme_cluster and String#grapheme_clusters is added to
    enumerate grapheme clusters [Feature #13780]
  * String#start_with? supports regexp [Feature #13712]

* Regexp/String: Update Unicode version from 9.0.0 to 10.0.0 [Feature #13685]

* Thread

  * Thread#fetch  [Feature #13009]

  * Description set by Thread#name= is now visible on Windows 10.

* Time

  * Time#at receives 3rd argument which specifies the unit of 2nd argument.
    [Feature #13919]

* KeyError

  * KeyError#receiver [Feature #12063]
  * KeyError#key      [Feature #12063]

=== Stdlib updates (outstanding ones only)

* Bundler

  * Add Bundler to Standard Library. [Feature #12733]

* DRb
  * ACL::ACLEntry.new no longer suppresses IPAddr::InvalidPrefixError.

* ERB
  * Add ERB#result_with_hash to render a template with local variables passed
    with a Hash object. [Feature #8631]
  * Default template file encoding is changed from ASCII-8BIT to UTF-8 in erb
    command. [Bug #14095]

  * Carriage returns are changed to be trimmed properly if trim_mode is specified
    and used. Duplicated newlines will be removed on Windows. [Bug #5339] [Bug #11464]

* IPAddr
  * New methods are added:
    * IPAddr#prefix
    * IPAddr#loopback?
    * IPAddr#private? [Feature #11666]
    * IPAddr#link_local? [Feature #10912]
  * IPAddr now rejects invalid address mask. [Bug #13399]
  * IPAddr#ipv4_compat and #ipv4_compat? are deprecated. [Bug #13769]

* IRB
  * `binding.irb` automatically requires irb and runs [Bug #13099] [experimental]
  * Show source around `binding.irb` on session start [Feature #14124]

* Net::HTTP
  * Net::HTTP.new supports no_proxy parameter [Feature #11195]

  * Net::HTTP#min_version/max_version [Feature #9450]

  * Add more HTTP status classes

  * Net::HTTP::STATUS_CODES is added as HTTP Status Code Repository [Misc #12935]

  * Net::HTTP#proxy_user and Net::HTTP#proxy_pass now reflects http_proxy
    environment variable if the system's environment variable is multiuser
    safe. [Bug #12921]

* Pathname
  * New method:
    * Pathname#glob [Feature #7360]

* Psych

  * Update to Psych 3.0.0.
    * Add :symbolize_names option to Psych.load, Psych.safe_load like JSON.parse
      https://github.com/ruby/psych/pull/333, https://github.com/ruby/psych/pull/337
    * Add Psych::Handler#event_location
      https://github.com/ruby/psych/pull/326
    * Make frozen string literal = true
      https://github.com/ruby/psych/pull/320
    * Preserve time zone offset when deserializing times
      https://github.com/ruby/psych/pull/316
    * Remove deprecated method aliases for syck gem
      https://github.com/ruby/psych/pull/312

* RbConfig
  * New constants:
    * RbConfig::LIMITS is added to provide the limits of C types.
      This is available when rbconfig/sizeof is required.

* Ripper
  * New method:
    * Ripper#state is added to tell the state of scanner. [Feature #13686]

  * New constants:
    * Ripper::EXPR_BEG and so on for Ripper#state.

* RDoc

  * Update to RDoc 6.0.0.beta3.
    * Replaced IRB based lexer with Ripper. It much improves the speed of generating document.
    * https://github.com/ruby/rdoc/pull/512

* Rubygems

  * Update to Rubygems 2.7.0.
    * http://blog.rubygems.org/2017/11/01/2.7.0-released.html
    * http://blog.rubygems.org/2017/08/27/2.6.13-released.html
    * http://blog.rubygems.org/2017/10/09/unsafe-object-deserialization-vulnerability.html

* SecureRandom
  * New methods:
    * SecureRandom.alphanumeric

* Set
  * Add Set#to_s as alias to #inspect [Feature #13676]
  * Add Set#=== as alias to #include? [Feature #13801]
  * Add Set#reset [Feature #6589]

* StringIO
  * StringIO#write accepts multiple arguments

* StringScanner
  * Add StringScanner#size, StringScanner#captures, StringScanner#values_at  [Feature #836]

* WEBrick

  * Add Server Name Indication (SNI) support [Feature #13729]

* Zlib
  * Zlib::GzipWriter#write accepts multiple arguments

=== Compatibility issues (excluding feature bug fixes)

* BasicSocket#read_nonblock and BasicSocket#write_nonblock no
  longer sets the O_NONBLOCK file description flag as side effect
  (on Linux only) [Feature #13362]

* Net::HTTP
  * Net::HTTP#start now pass :ENV to p_addr by default. [Bug #13351]
    To avoid this, pass nil explicitly.

* Random.raw_seed renamed to become Random.urandom.  It is now
  applicable to non-seeding purposes due to [Bug #9569].

* Socket::Ifaddr#vhid is added [Feature #13803]

* ConditionVariable, Queue and SizedQueue reimplemented for speed.
  They no longer subclass Struct. [Feature #13552]

=== Stdlib compatibility issues (excluding feature bug fixes)

* mathn.rb
  Removed from stdlib. [Feature #10169]

* Rubygems
  * Removed "ubygems.rb" file from stdlib. It's needless since Ruby 1.9.

=== C API updates

=== Supported platform changes

* Drop to support NaCl platform
  * https://bugs.chromium.org/p/chromium/issues/detail?id=239656#c160

=== Implementation improvements

* (This might not be a "user visible feature change" but) Hash class's
  hash function is now SipHash13. [Feature #13017]

* SecureRandom now prefers OS-provided sources than OpenSSL. [Bug #9569]

* Mutex rewritten to be smaller and faster [Feature #13517]

* Performance of block passing using block parameters is improved by
  lazy Proc allocation [Feature #14045]

* Dynamic instrumentation for TracePoint hooks instead of using "trace"
  instruction to avoid overhead [Feature #14104]

=== Miscellaneous changes

* Print backtrace and error message in reverse order if STDERR is unchanged and a tty.
  [Feature #8661] [experimental]

* Print error message in bold/underlined text if STDERR is unchanged and a tty.
  [Feature #14140] [experimental]

* configure option --with-ext now mandates its arguments.  So for
  instance if you run ./configure --with-ext=openssl,+ then the
  openssl library is guaranteed compiled, otherwise the build fails
  abnormally.

  Note however to always add the ",+" at the end of the argument.
  Otherwise nothing but openssl are built.  [Feature #13302]