[GR-19220] Add Enumerator.product

PullRequest: truffleruby/3929

Author: andrykonchin

CHANGELOG.md

@@ -35,6 +35,7 @@ Compatibility:
 * Add `Thread.each_caller_location` (#3039, @itarato).
 * Add `timeout` argument to `Thread::SizedQueue#push` (#3039, @itarato).
 * Add `rb_syserr_new` function (@rwstauner).
+* Add `Enumerator#product` (#3039, @itarato).
 
 Performance:
 

spec/ruby/core/enumerator/chain/initialize_spec.rb

@@ -22,10 +22,10 @@
   end
 
   describe "on frozen instance" do
-    it "raises a RuntimeError" do
+    it "raises a FrozenError" do
       -> {
         @uninitialized.freeze.send(:initialize)
-      }.should raise_error(RuntimeError)
+      }.should raise_error(FrozenError)
     end
   end
 end

spec/ruby/core/enumerator/each_spec.rb

@@ -10,41 +10,41 @@ def object_each_with_arguments.each_with_arguments(arg, *args)
 
     @enum_with_arguments = object_each_with_arguments.to_enum(:each_with_arguments, :arg0, :arg1, :arg2)
 
-    @enum_with_yielder = Enumerator.new {|y| y.yield :ok}
+    @enum_with_yielder = Enumerator.new { |y| y.yield :ok }
   end
 
   it "yields each element of self to the given block" do
     acc = []
-    [1,2,3].to_enum.each {|e| acc << e }
-    acc.should == [1,2,3]
+    [1, 2, 3].to_enum.each { |e| acc << e }
+    acc.should == [1, 2, 3]
   end
 
   it "calls #each on the object given in the constructor by default" do
     each = mock('each')
     each.should_receive(:each)
-    each.to_enum.each {|e| e }
+    each.to_enum.each { |e| e }
   end
 
   it "calls #each on the underlying object until it's exhausted" do
     each = mock('each')
     each.should_receive(:each).and_yield(1).and_yield(2).and_yield(3)
     acc = []
-    each.to_enum.each {|e| acc << e }
-    acc.should == [1,2,3]
+    each.to_enum.each { |e| acc << e }
+    acc.should == [1, 2, 3]
   end
 
   it "calls the method given in the constructor instead of #each" do
     each = mock('peach')
     each.should_receive(:peach)
-    each.to_enum(:peach).each {|e| e }
+    each.to_enum(:peach).each { |e| e }
   end
 
   it "calls the method given in the constructor until it's exhausted" do
     each = mock('peach')
     each.should_receive(:peach).and_yield(1).and_yield(2).and_yield(3)
     acc = []
-    each.to_enum(:peach).each {|e| acc << e }
-    acc.should == [1,2,3]
+    each.to_enum(:peach).each { |e| acc << e }
+    acc.should == [1, 2, 3]
   end
 
   it "raises a NoMethodError if the object doesn't respond to #each" do

spec/ruby/core/enumerator/generator/initialize_spec.rb

@@ -17,10 +17,10 @@
   end
 
   describe "on frozen instance" do
-    it "raises a RuntimeError" do
+    it "raises a FrozenError" do
       -> {
         @uninitialized.freeze.send(:initialize) {}
-      }.should raise_error(RuntimeError)
+      }.should raise_error(FrozenError)
     end
   end
 end

spec/ruby/core/enumerator/initialize_spec.rb

@@ -48,10 +48,10 @@
   end
 
   describe "on frozen instance" do
-    it "raises a RuntimeError" do
+    it "raises a FrozenError" do
       -> {
         @uninitialized.freeze.send(:initialize) {}
-      }.should raise_error(RuntimeError)
+      }.should raise_error(FrozenError)
     end
   end
 end

spec/ruby/core/enumerator/lazy/initialize_spec.rb

@@ -56,8 +56,8 @@ def receiver.each
   end
 
   describe "on frozen instance" do
-    it "raises a RuntimeError" do
-      -> {  @uninitialized.freeze.send(:initialize, @receiver) {} }.should raise_error(RuntimeError)
+    it "raises a FrozenError" do
+      -> {  @uninitialized.freeze.send(:initialize, @receiver) {} }.should raise_error(FrozenError)
     end
   end
 end

spec/ruby/core/enumerator/product/each_spec.rb

@@ -0,0 +1,73 @@
+require_relative '../../../spec_helper'
+require_relative '../../enumerable/shared/enumeratorized'
+
+ruby_version_is "3.2" do
+  describe "Enumerator::Product#each" do
+    it_behaves_like :enumeratorized_with_origin_size, :each, Enumerator::Product.new([1, 2], [:a, :b])
+
+    it "yields each element of Cartesian product of enumerators" do
+      enum = Enumerator::Product.new([1, 2], [:a, :b])
+      acc = []
+      enum.each { |e| acc << e }
+      acc.should == [[1, :a], [1, :b], [2, :a], [2, :b]]
+    end
+
+    it "calls #each_entry method on enumerators" do
+      object1 = Object.new
+      def object1.each_entry
+        yield 1
+        yield 2
+      end
+
+      object2 = Object.new
+      def object2.each_entry
+        yield :a
+        yield :b
+      end
+
+      enum = Enumerator::Product.new(object1, object2)
+      acc = []
+      enum.each { |e| acc << e }
+      acc.should == [[1, :a], [1, :b], [2, :a], [2, :b]]
+    end
+
+    it "raises a NoMethodError if the object doesn't respond to #each_entry" do
+      -> {
+        Enumerator::Product.new(Object.new).each {}
+      }.should raise_error(NoMethodError, /undefined method `each_entry' for/)
+    end
+
+    it "returns enumerator if not given a block" do
+      enum = Enumerator::Product.new([1, 2], [:a, :b])
+      enum.each.should.kind_of?(Enumerator)
+
+      enum = Enumerator::Product.new([1, 2], [:a, :b])
+      enum.each.to_a.should == [[1, :a], [1, :b], [2, :a], [2, :b]]
+    end
+
+    it "returns self if given a block" do
+      enum = Enumerator::Product.new([1, 2], [:a, :b])
+      enum.each {}.should.equal?(enum)
+    end
+
+    it "doesn't accept arguments" do
+      Enumerator::Product.instance_method(:each).arity.should == 0
+    end
+
+    it "yields each element to a block that takes multiple arguments" do
+      enum = Enumerator::Product.new([1, 2], [:a, :b])
+
+      acc = []
+      enum.each { |x, y| acc << x }
+      acc.should == [1, 1, 2, 2]
+
+      acc = []
+      enum.each { |x, y| acc << y }
+      acc.should == [:a, :b, :a, :b]
+
+      acc = []
+      enum.each { |x, y, z| acc << z }
+      acc.should == [nil, nil, nil, nil]
+    end
+  end
+end

spec/ruby/core/enumerator/product/initialize_copy_spec.rb

@@ -0,0 +1,54 @@
+require_relative '../../../spec_helper'
+
+ruby_version_is "3.2" do
+  describe "Enumerator::Product#initialize_copy" do
+    it "replaces content of the receiver with content of the other object" do
+      enum = Enumerator::Product.new([true, false])
+      enum2 = Enumerator::Product.new([1, 2], [:a, :b])
+
+      enum.send(:initialize_copy, enum2)
+      enum.each.to_a.should == [[1, :a], [1, :b], [2, :a], [2, :b]]
+    end
+
+    it "returns self" do
+      enum = Enumerator::Product.new([true, false])
+      enum2 = Enumerator::Product.new([1, 2], [:a, :b])
+
+      enum.send(:initialize_copy, enum2).should.equal?(enum)
+    end
+
+    it "is a private method" do
+      Enumerator::Product.should have_private_instance_method(:initialize_copy, false)
+    end
+
+    it "does nothing if the argument is the same as the receiver" do
+      enum = Enumerator::Product.new(1..2)
+      enum.send(:initialize_copy, enum).should.equal?(enum)
+
+      enum.freeze
+      enum.send(:initialize_copy, enum).should.equal?(enum)
+    end
+
+    it "raises FrozenError if the receiver is frozen" do
+      enum = Enumerator::Product.new(1..2)
+      enum2 = Enumerator::Product.new(3..4)
+
+      -> { enum.freeze.send(:initialize_copy, enum2) }.should raise_error(FrozenError)
+    end
+
+    it "raises TypeError if the objects are of different class" do
+      enum = Enumerator::Product.new(1..2)
+      enum2 = Class.new(Enumerator::Product).new(3..4)
+
+      -> { enum.send(:initialize_copy, enum2) }.should raise_error(TypeError, 'initialize_copy should take same class object')
+      -> { enum2.send(:initialize_copy, enum) }.should raise_error(TypeError, 'initialize_copy should take same class object')
+    end
+
+    it "raises ArgumentError if the argument is not initialized yet" do
+      enum = Enumerator::Product.new(1..2)
+      enum2 = Enumerator::Product.allocate
+
+      -> { enum.send(:initialize_copy, enum2) }.should raise_error(ArgumentError, 'uninitialized product')
+    end
+  end
+end

spec/ruby/core/enumerator/product/initialize_spec.rb

@@ -0,0 +1,33 @@
+require_relative '../../../spec_helper'
+
+ruby_version_is "3.2" do
+  describe "Enumerator::Product#initialize" do
+    before :each do
+      @uninitialized = Enumerator::Product.allocate
+    end
+
+    it "is a private method" do
+      Enumerator::Product.should have_private_instance_method(:initialize, false)
+    end
+
+    it "returns self" do
+      @uninitialized.send(:initialize).should equal(@uninitialized)
+    end
+
+    it "accepts many arguments" do
+      @uninitialized.send(:initialize, 0..1, 2..3, 4..5).should equal(@uninitialized)
+    end
+
+    it "accepts arguments that are not Enumerable nor responding to :each_entry" do
+      @uninitialized.send(:initialize, Object.new).should equal(@uninitialized)
+    end
+
+    describe "on frozen instance" do
+      it "raises a FrozenError" do
+        -> {
+          @uninitialized.freeze.send(:initialize, 0..1)
+        }.should raise_error(FrozenError)
+      end
+    end
+  end
+end

spec/ruby/core/enumerator/product/inspect_spec.rb

@@ -0,0 +1,22 @@
+require_relative '../../../spec_helper'
+
+ruby_version_is "3.2" do
+  describe "Enumerator::Product#inspect" do
+    it "returns a String including enumerators" do
+      enum = Enumerator::Product.new([1, 2], [:a, :b])
+      enum.inspect.should == "#<Enumerator::Product: [[1, 2], [:a, :b]]>"
+    end
+
+    it "represents a recursive element with '[...]'" do
+      enum = [1, 2]
+      enum_recursive = Enumerator::Product.new(enum)
+
+      enum << enum_recursive
+      enum_recursive.inspect.should == "#<Enumerator::Product: [[1, 2, #<Enumerator::Product: ...>]]>"
+    end
+
+    it "returns a not initialized representation if #initialized is not called yet" do
+      Enumerator::Product.allocate.inspect.should == "#<Enumerator::Product: uninitialized>"
+    end
+  end
+end