# -*- 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]

* 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]

* Hash

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

* IO

  * IO#pread  [Feature #4532]
  * IO#pwrite  [Feature #4532]

* 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]

* Kernel

  * Kernel#yield_self  [Feature #6721]

* Net::HTTP

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

* 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 6.1.1.
    * 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]

* Regexp/String: Updated 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]

* ERB
  * Add ERB#result_with_hash to render a template with local variables passed
    with a Hash object. [Feature #8631]

  * 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]

* Net::HTTP
  * 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]

* RbConfig
  * New constants:
    * RbConfig::LIMITS is added to provide the limits of C types.

* 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.

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

* WEBrick

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

=== 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 after the Ruby 1.9.

=== C API updates

=== Supported platform changes

=== 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]

=== Miscellaneous changes

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