diff --git a/NEWS b/NEWS index a8dc17cbc8..78db0a7637 100644 --- a/NEWS +++ b/NEWS @@ -14,10 +14,40 @@ sufficient information, see the ChangeLog file or Redmine === Language changes +==== Pattern matching + * Pattern matching is introduced as an experimental feature. [Feature #14912] -* Method reference operator, .: is introduced as an - experimental feature. [Feature #12125] [Feature #13581] + 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 + + json = < 2 + end + +* See the following slides in detail + * https://speakerdeck.com/k_tsj/pattern-matching-new-feature-in-ruby-2-dot-7 + +==== 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] @@ -64,6 +94,9 @@ sufficient information, see the ChangeLog file or Redmine * Non-symbols are allowed as a keyword argument keys if 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} * **nil is allowed in method definitions to explicitly mark @@ -86,17 +119,32 @@ sufficient information, see the ChangeLog file or Redmine h = {}; def foo(*a) a end; foo(h) # [{}] h = {}; def foo(a) a end; foo(h) # {} -* Proc.new and Kernel#proc with no block in a method called with a block is - warned now. - -* Kernel#lambda with no block in a method called with a block errs. - -* Non-Symbol keys in a keyword arguments hash were prohibited in 2.6.0, - but are now allowed again. [Bug #15658] +==== Numbered parameter * Numbered parameter as the default block parameter is introduced as an experimental feature. [Feature #4475] + [1, 2, 10].map { _1.to_s(16) } #=> ["1", "2", "a"] + +==== proc/lambda without no block is deprecated + +* Proc.new and Kernel#proc with no block in a method called with a block is + warned now. + + def foo + proc + end + foo { puts "Hello" } #=> warning: Capturing the given block using Proc.new is deprecated; use `&block` instead + +* 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 not be as useful as an endless range, but would be good for DSL purpose. [Feature #14799] @@ -112,10 +160,9 @@ sufficient information, see the ChangeLog file or Redmine * Quoted here-document identifier must end within the same line. <<"EOS - " # This has been warned since 2.4 + " # 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. @@ -134,6 +181,9 @@ sufficient information, see the ChangeLog file or Redmine # Previously parsed as: (a, b = raise) rescue [1, 2] # Now parsed as: a, b = (raise rescue [1, 2]) +* Method reference operator, .: is introduced as an + experimental feature. [Feature #12125] [Feature #13581] + === Core classes updates (outstanding ones only) Array:: @@ -148,6 +198,10 @@ Comparable:: * Comparable#clamp now accepts a Range argument. [Feature #14784] + -1.clamp(0..2) #=> 0 + 1.clamp(0..2) #=> 1 + 3.clamp(0..2) #=> 2 + Complex:: New method:: @@ -163,7 +217,9 @@ Dir:: Encoding:: - * Added new encoding CESU-8 [Feature #15931] + New method:: + + * Added new encoding CESU-8 [Feature #15931] Enumerable:: @@ -171,8 +227,12 @@ Enumerable:: * 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 method:: @@ -192,6 +252,7 @@ Fiber:: exception on the resumed fiber. [Feature #10344] File:: + Modified method:: * File.extname now returns a dot string at a name ending with a dot on @@ -311,7 +372,7 @@ Time:: UnboundMethod:: - New methods:: + New method:: * Added UnboundMethod#bind_call method. [Feature #15955]