[GR-45621] Promote Set class to core library

CHANGELOG.md

@@ -44,6 +44,7 @@ Compatibility:
 * Do not autosplat a proc that accepts a single positional argument and keywords (#3039, @andrykonchin).
 * Support passing anonymous * and ** parameters as method call arguments (#3039, @andrykonchin).
 * Handle either positional or keywords arguments by default in `Struct.new` (#3039, @rwstauner).
+* Promote `Set` class to core library (#3039, @andrykonchin).
 
 Performance:
 

spec/ruby/core/enumerable/fixtures/classes.rb

@@ -342,4 +342,10 @@ def ===(*args)
       @block.call(*args)
     end
   end
+
+  # Set is a core class since Ruby 3.2
+  ruby_version_is '3.2' do
+    class SetSubclass < Set
+    end
+  end
 end # EnumerableSpecs utility classes

spec/ruby/core/enumerable/to_set_spec.rb

@@ -0,0 +1,29 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+ruby_version_is "3.2" do
+  describe "Enumerable#to_set" do
+    it "returns a new Set created from self" do
+      [1, 2, 3].to_set.should == Set[1, 2, 3]
+      {a: 1, b: 2}.to_set.should == Set[[:b, 2], [:a, 1]]
+    end
+
+    it "passes down passed blocks" do
+      [1, 2, 3].to_set { |x| x * x }.should == Set[1, 4, 9]
+    end
+
+    it "instantiates an object of provided as the first argument set class" do
+      set = [1, 2, 3].to_set(EnumerableSpecs::SetSubclass)
+      set.should be_kind_of(EnumerableSpecs::SetSubclass)
+      set.to_a.sort.should == [1, 2, 3]
+    end
+
+    it "does not need explicit `require 'set'`" do
+      output = ruby_exe(<<~RUBY, options: '--disable-gems', args: '2>&1')
+        puts [1, 2, 3].to_set
+      RUBY
+
+      output.chomp.should == "#<Set: {1, 2, 3}>"
+    end
+  end
+end

spec/ruby/library/set/set_spec.rb

@@ -0,0 +1,12 @@
+require_relative '../../spec_helper'
+
+describe 'Set' do
+  ruby_version_is '3.2' do
+    it 'is available without explicit requiring' do
+      output = ruby_exe(<<~RUBY, options: '--disable-gems', args: '2>&1')
+        puts Set.new([1, 2, 3])
+      RUBY
+      output.chomp.should == "#<Set: {1, 2, 3}>"
+    end
+  end
+end

spec/tags/core/enumerable/to_set_tags.txt

@@ -0,0 +1 @@
+slow:Enumerable#to_set does not need explicit `require 'set'`

spec/tags/library/set/set_tags.txt

@@ -0,0 +1 @@
+slow:Set is available without explicit requiring

src/main/ruby/truffleruby/core/enumerable.rb

@@ -332,6 +332,10 @@ def to_h(*arg)
     h
   end
 
+  def to_set(klass = Set, ...)
+    klass.new(self, ...)
+  end
+
   # Synchronize with Enumerator#zip and Array#zip
   def zip(*enums)
     enums.map! do |enum|

src/main/ruby/truffleruby/core/post.rb

@@ -112,3 +112,8 @@ def p(*a)
     $LOAD_PATH.unshift(*extra_load_paths.map { |path| File.expand_path(path) })
   end
 end
+
+# Set class is in the core library but it's still possible to require it as a standard
+# library with `require`. So it doesn't make sense to have two copies of the same code
+# and it's easier just to autoload CRuby's provided source file here.
+autoload :Set, 'set'

src/main/ruby/truffleruby/core/truffle/versioned_array.rb

@@ -655,6 +655,11 @@ def to_s(*args, &block)
     copy.to_s(*args, &block)
   end
 
+  def to_set(*args, &block)
+    copy = TruffleRuby.synchronized(@lock) { Array.new self }
+    copy.to_set(*args, &block)
+  end
+
   def transpose(*args, &block)
     copy = TruffleRuby.synchronized(@lock) { Array.new self }
     copy.transpose(*args, &block)