# -*- 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]

=== Core classes updates (outstanding ones only)

* Array

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

* 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]

* IO

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

* IOError

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

* Kernel

  * Kernel#yield_self  [Feature #6721]

* Numeric

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

* 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 Onigmo 6.1.1.
    * Support absent operator https://github.com/k-takata/Onigmo/issues/82

* Thread

  * Thread#fetch  [Feature #13009]

* 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]

=== Stdlib updates (outstanding ones only)

* Net::HTTP
  * 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.

=== Compatibility issues (excluding feature bug fixes)

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

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

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

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

=== 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]

=== Miscellaneous changes

* 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]