Merge pull request #4690 from jruby/test-set-native

native implementation of set.rb
jruby · Sep 17, 2017 · 7a6eb69 · 7a6eb69
2 parents dce612e + f9d0d0f
commit 7a6eb69
Showing 12 changed files with 1,875 additions and 36 deletions.
diff --git a/core/src/main/java/org/jruby/Ruby.java b/core/src/main/java/org/jruby/Ruby.java
@@ -1719,6 +1719,7 @@ private void initBuiltins() {
         addLazyBuiltin("tempfile.jar", "tempfile", "org.jruby.ext.tempfile.TempfileLibrary");
         addLazyBuiltin("fcntl.rb", "fcntl", "org.jruby.ext.fcntl.FcntlLibrary");
         addLazyBuiltin("pathname.jar", "pathname", "org.jruby.ext.pathname.PathnameLibrary");
+        addLazyBuiltin("set.rb", "set", "org.jruby.ext.set.SetLibrary");
 
         addLazyBuiltin("mathn/complex.jar", "mathn/complex", "org.jruby.ext.mathn.Complex");
         addLazyBuiltin("mathn/rational.jar", "mathn/rational", "org.jruby.ext.mathn.Rational");

diff --git a/core/src/main/java/org/jruby/RubyArray.java b/core/src/main/java/org/jruby/RubyArray.java
@@ -3483,42 +3483,134 @@ public IRubyObject sort_bang19(ThreadContext context, Block block) {
         return sort_bang(context, block);
     }
 
-    protected IRubyObject sortInternal(final ThreadContext context, boolean honorOverride) {
-        Ruby runtime = context.runtime;
-
-        // One check per specialized fast-path to make the check invariant.
-        final boolean fixnumBypass = !honorOverride || runtime.getFixnum().isMethodBuiltin("<=>");
-        final boolean stringBypass = !honorOverride || runtime.getString().isMethodBuiltin("<=>");
-
+    protected IRubyObject sortInternal(final ThreadContext context, final boolean honorOverride) {
         try {
-            Arrays.sort(values, begin, begin + realLength, new Comparator() {
-                public int compare(Object o1, Object o2) {
-                    if (fixnumBypass && o1 instanceof RubyFixnum && o2 instanceof RubyFixnum) {
-                        return compareFixnums((RubyFixnum) o1, (RubyFixnum) o2);
-                    }
-                    if (stringBypass && o1 instanceof RubyString && o2 instanceof RubyString) {
-                        return ((RubyString) o1).op_cmp((RubyString) o2);
-                    }
-                    return compareOthers(context, (IRubyObject)o1, (IRubyObject)o2);
+            Arrays.sort(values, begin, begin + realLength, new DefaultComparator(context, honorOverride) {
+                protected int compareGeneric(IRubyObject o1, IRubyObject o2) {
+                    //TODO: ary_sort_check should be done here
+                    return super.compareGeneric(o1, o2);
                 }
             });
-        } catch (ArrayIndexOutOfBoundsException ex) {
+        }
+        catch (ArrayIndexOutOfBoundsException ex) {
             throw concurrentModification(context.runtime, ex);
         }
         return this;
     }
 
+    // @Deprecated
     protected static int compareFixnums(RubyFixnum o1, RubyFixnum o2) {
-        long a = o1.getLongValue();
-        long b = o2.getLongValue();
-        return a > b ? 1 : a == b ? 0 : -1;
+        return DefaultComparator.compareInteger(o1, o2);
     }
 
+    // @Deprecated
     protected static int compareOthers(ThreadContext context, IRubyObject o1, IRubyObject o2) {
-        IRubyObject ret = sites(context).op_cmp_sort.call(context, o1, o1, o2);
-        int n = RubyComparable.cmpint(context, ret, o1, o2);
-        //TODO: ary_sort_check should be done here
-        return n;
+        return DefaultComparator.compareGeneric(context, o1, o2);
+    }
+
+    public static class DefaultComparator implements Comparator<IRubyObject> {
+
+        final ThreadContext context;
+
+        private final boolean fixnumBypass;
+        private final boolean stringBypass;
+
+        public DefaultComparator(ThreadContext context) {
+            this(context, true);
+        }
+
+        DefaultComparator(ThreadContext context, final boolean honorOverride) {
+            this.context = context;
+            if ( honorOverride && context != null ) {
+                this.fixnumBypass = !honorOverride || context.runtime.getFixnum().isMethodBuiltin("<=>");
+                this.stringBypass = !honorOverride || context.runtime.getString().isMethodBuiltin("<=>");
+            }
+            else { // no-opt
+                this.fixnumBypass = false;
+                this.stringBypass = false;
+            }
+        }
+
+        /*
+        DefaultComparator(ThreadContext context, final boolean fixnumBypass, final boolean stringBypass) {
+            this.context = context;
+            this.fixnumBypass = fixnumBypass;
+            this.stringBypass = stringBypass;
+        } */
+
+        public int compare(IRubyObject obj1, IRubyObject obj2) {
+            if (fixnumBypass && obj1 instanceof RubyFixnum && obj2 instanceof RubyFixnum) {
+                return compareInteger((RubyFixnum) obj1, (RubyFixnum) obj2);
+            }
+            if (stringBypass && obj1 instanceof RubyString && obj2 instanceof RubyString) {
+                return compareString((RubyString) obj1, (RubyString) obj2);
+            }
+            return compareGeneric(obj1, obj2);
+        }
+
+        protected int compareGeneric(IRubyObject o1, IRubyObject o2) {
+            final ThreadContext context = context();
+            return compareGeneric(context, sites(context).op_cmp_sort, o1, o2);
+        }
+
+        protected ThreadContext context() {
+            return context;
+        }
+
+        public static int compareInteger(RubyFixnum o1, RubyFixnum o2) {
+            long a = o1.getLongValue();
+            long b = o2.getLongValue();
+            return a > b ? 1 : a == b ? 0 : -1;
+        }
+
+        public static int compareString(RubyString o1, RubyString o2) {
+            return o1.op_cmp(o2);
+        }
+
+        public static int compareGeneric(ThreadContext context, IRubyObject o1, IRubyObject o2) {
+            return compareGeneric(context, sites(context).op_cmp_sort, o1, o2);
+        }
+
+        public static int compareGeneric(ThreadContext context, CallSite op_cmp_sort, IRubyObject o1, IRubyObject o2) {
+            IRubyObject ret = op_cmp_sort.call(context, o1, o1, o2);
+            return RubyComparable.cmpint(context, ret, o1, o2);
+        }
+
+    }
+
+    static class BlockComparator implements Comparator<IRubyObject> {
+
+        final ThreadContext context;
+
+        protected final Block block;
+        protected final IRubyObject self;
+
+        private final CallSite gt;
+        private final CallSite lt;
+
+        BlockComparator(ThreadContext context, Block block, CallSite gt, CallSite lt) {
+            this(context, block, null, gt, lt);
+        }
+
+        BlockComparator(ThreadContext context, Block block, IRubyObject self, CallSite gt, CallSite lt) {
+            this.context = context == null ? self.getRuntime().getCurrentContext() : context;
+            this.block = block; this.self = self;
+            this.gt = gt; this.lt = lt;
+        }
+
+        public int compare(IRubyObject obj1, IRubyObject obj2) {
+            return RubyComparable.cmpint(context, gt, lt, yieldBlock(obj1, obj2), obj1, obj2);
+        }
+
+        protected final IRubyObject yieldBlock(IRubyObject obj1, IRubyObject obj2) {
+            final ThreadContext context = context();
+            return block.yieldArray(context, context.runtime.newArray(obj1, obj2), self);
+        }
+
+        protected final ThreadContext context() {
+            return context;
+        }
+
     }
 
     protected IRubyObject sortInternal(final ThreadContext context, final Block block) {
@@ -3528,15 +3620,13 @@ protected IRubyObject sortInternal(final ThreadContext context, final Block bloc
         int length = realLength;
 
         copyInto(newValues, 0);
-        Arrays.sort(newValues, 0, length, new Comparator() {
-            CallSite gt = sites(context).op_gt_sort;
-            CallSite lt = sites(context).op_lt_sort;
-            public int compare(Object o1, Object o2) {
-                IRubyObject obj1 = (IRubyObject) o1;
-                IRubyObject obj2 = (IRubyObject) o2;
-                IRubyObject ret = block.yieldArray(context, getRuntime().newArray(obj1, obj2), null);
+        CallSite gt = sites(context).op_gt_sort;
+        CallSite lt = sites(context).op_lt_sort;
+        Arrays.sort(newValues, 0, length, new BlockComparator(context, block, gt, lt) {
+            @Override
+            public int compare(IRubyObject obj1, IRubyObject obj2) {
                 //TODO: ary_sort_check should be done here
-                return RubyComparable.cmpint(context, gt, lt, ret, obj1, obj2);
+                return super.compare(obj1, obj2);
             }
         });
 

diff --git a/core/src/main/java/org/jruby/RubyModule.java b/core/src/main/java/org/jruby/RubyModule.java
@@ -3522,7 +3522,8 @@ public IRubyObject prepended(ThreadContext context, IRubyObject other) {
         return context.nil;
     }
 
-    final void setConstantVisibility(Ruby runtime, String name, boolean hidden) {
+    // NOTE: internal API
+    public final void setConstantVisibility(Ruby runtime, String name, boolean hidden) {
         ConstantEntry entry = getConstantMap().get(name);
 
         if (entry == null) {

diff --git a/core/src/main/java/org/jruby/ext/set/EnumerableExt.java b/core/src/main/java/org/jruby/ext/set/EnumerableExt.java
@@ -0,0 +1,63 @@
+/***** BEGIN LICENSE BLOCK *****
+ * Version: EPL 1.0/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Eclipse Public
+ * License Version 1.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * Copyright (C) 2016 Karol Bucek
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either of the GNU General Public License Version 2 or later (the "GPL"),
+ * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the EPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the EPL, the GPL or the LGPL.
+ ***** END LICENSE BLOCK *****/
+package org.jruby.ext.set;
+
+import org.jruby.Ruby;
+import org.jruby.RubyClass;
+import org.jruby.anno.JRubyMethod;
+import org.jruby.runtime.Block;
+import org.jruby.runtime.ThreadContext;
+import org.jruby.runtime.builtin.IRubyObject;
+
+/**
+ * Enumerable#to_set (from require 'set')
+ *
+ * @author kares
+ */
+public abstract class EnumerableExt {
+
+    //@JRubyMethod
+    public static IRubyObject to_set(final ThreadContext context, final IRubyObject self, final Block block) {
+        final Ruby runtime = context.runtime;
+
+        RubySet set = new RubySet(runtime, runtime.getClass("Set"));
+        set.initialize(context, self, block);
+        return set; // return runtime.getClass("Set").newInstance(context, self, block);
+    }
+
+    @JRubyMethod(rest = true) // to_set(klass = Set, *args, &block)
+    public static IRubyObject to_set(final ThreadContext context, final IRubyObject self,
+        final IRubyObject[] args, final Block block) {
+
+        if ( args.length == 0 ) return to_set(context, self, block);
+
+        final IRubyObject klass = args[0]; args[0] = self;
+        return ((RubyClass) klass).newInstance(context, args, block);
+    }
+
+}
diff --git a/core/src/main/java/org/jruby/ext/set/RubySet.java b/core/src/main/java/org/jruby/ext/set/RubySet.java
diff --git a/core/src/main/java/org/jruby/ext/set/RubySortedSet.java b/core/src/main/java/org/jruby/ext/set/RubySortedSet.java
@@ -0,0 +1,227 @@
+/*
+ **** BEGIN LICENSE BLOCK *****
+ * Version: EPL 1.0/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Eclipse Public
+ * License Version 1.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * Copyright (C) 2016 Karol Bucek
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either of the GNU General Public License Version 2 or later (the "GPL"),
+ * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the EPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the EPL, the GPL or the LGPL.
+ ***** END LICENSE BLOCK *****/
+package org.jruby.ext.set;
+
+import org.jruby.*;
+import org.jruby.anno.JRubyMethod;
+import org.jruby.runtime.*;
+import org.jruby.runtime.builtin.IRubyObject;
+
+import java.util.*;
+
+import static org.jruby.RubyArray.DefaultComparator;
+
+/**
+ * Native implementation of Ruby's SortedSet (set.rb replacement).
+ *
+ * @author kares
+ */
+@org.jruby.anno.JRubyClass(name="SortedSet", parent = "Set")
+public class RubySortedSet extends RubySet implements SortedSet {
+
+    static RubyClass createSortedSetClass(final Ruby runtime) {
+        RubyClass SortedSet = runtime.defineClass("SortedSet", runtime.getClass("Set"), ALLOCATOR);
+
+        SortedSet.setReifiedClass(RubySortedSet.class);
+        SortedSet.defineAnnotatedMethods(RubySortedSet.class);
+
+        return SortedSet;
+    }
+
+    private static final ObjectAllocator ALLOCATOR = new ObjectAllocator() {
+        public RubySortedSet allocate(Ruby runtime, RubyClass klass) {
+            return new RubySortedSet(runtime, klass);
+        }
+    };
+
+    private static class OrderComparator extends DefaultComparator {
+
+        private final Ruby runtime;
+
+        OrderComparator(final Ruby runtime) {
+            super(null); this.runtime = runtime;
+        }
+
+        @Override
+        protected ThreadContext context() {
+            return runtime.getCurrentContext();
+        }
+    }
+
+    private final TreeSet<IRubyObject> order;
+
+    protected RubySortedSet(Ruby runtime, RubyClass klass) {
+        super(runtime, klass);
+        order = new TreeSet<>(new OrderComparator(runtime));
+    }
+
+    @Override
+    void unmarshal() {
+        super.unmarshal();
+        IRubyObject[] elems = hash.keys().toJavaArrayMaybeUnsafe();
+        for ( int i=0; i<elems.length; i++ ) order.add( elems[i] );
+    }
+
+    @JRubyMethod(name = "[]", rest = true, meta = true) // re-def Set[] for SortedSet
+    public static RubySortedSet create(final ThreadContext context, IRubyObject self, IRubyObject... ary) {
+        final Ruby runtime = context.runtime;
+
+        RubySortedSet set = new RubySortedSet(runtime, (RubyClass) self);
+        return (RubySortedSet) set.initSet(context, ary, 0, ary.length);
+    }
+
+    @Override
+    protected void addImpl(final Ruby runtime, final IRubyObject obj) {
+        // NOTE: we're able to function without the check - comparator will raise ArgumentError
+        //if ( ! obj.respondsTo("<=>") ) {
+        //    throw runtime.newArgumentError("value must respond to <=>");
+        //}
+        super.addImpl(runtime, obj); // @hash[obj] = true
+        order.add(obj);
+    }
+
+    @Override
+    protected void addImplSet(final ThreadContext context, final RubySet set) {
+        super.addImplSet(context, set);
+        order.addAll(set.elements());
+    }
+
+    @Override
+    protected boolean deleteImpl(final IRubyObject obj) {
+        if ( super.deleteImpl(obj) ) {
+            order.remove(obj); return true;
+        }
+        return false;
+    }
+
+    @Override
+    protected void deleteImplIterator(final IRubyObject obj, final Iterator it) {
+        super.deleteImpl(obj);
+        // iterator over elementsOrdered()
+        it.remove(); // order.remove(obj)
+    }
+
+    @Override
+    protected void clearImpl() {
+        hash.rb_clear();
+        order.clear();
+    }
+
+    @JRubyMethod(name = "sort") // re-def Enumerable#sort
+    public RubyArray sort(final ThreadContext context) {
+        return RubyArray.newArray(context.runtime, order); // instead of this.hash.keys();
+    }
+
+    @Override
+    public RubyArray to_a(final ThreadContext context) {
+        return sort(context); // instead of this.hash.keys();
+    }
+
+    // NOTE: weirdly Set/SortedSet in Ruby do not have sort!
+
+    @Override
+    protected Set<IRubyObject> elementsOrdered() { return order; }
+
+    @Override
+    public Iterator<Object> iterator() {
+        return new JavaIterator();
+    }
+
+    // java.util.SortedSet :
+
+    public Comparator<? super IRubyObject> comparator() {
+        return order.comparator();
+    }
+
+    public Object first() {
+        return firstValue().toJava(Object.class);
+    }
+
+    public IRubyObject firstValue() {
+        return order.first();
+    }
+
+    public Object last() {
+        return lastValue().toJava(Object.class);
+    }
+
+    public IRubyObject lastValue() {
+        return order.last();
+    }
+
+    public SortedSet headSet(Object toElement) {
+        throw new UnsupportedOperationException("NOT IMPLEMENTED");
+    }
+
+    public SortedSet subSet(Object fromElement, Object toElement) {
+        throw new UnsupportedOperationException("NOT IMPLEMENTED");
+    }
+
+    public SortedSet tailSet(Object fromElement) {
+        throw new UnsupportedOperationException("NOT IMPLEMENTED");
+    }
+
+    public SortedSet<IRubyObject> rawHeadSet(IRubyObject toElement) {
+        return order.headSet(toElement);
+    }
+
+    public SortedSet<IRubyObject> rawSubSet(IRubyObject fromElement, IRubyObject toElement) {
+        return order.subSet(fromElement, toElement);
+    }
+
+    public SortedSet<IRubyObject> rawTailSet(IRubyObject fromElement) {
+        return order.tailSet(fromElement);
+    }
+
+    private class JavaIterator implements Iterator<Object> {
+
+        private final Iterator<IRubyObject> rawIterator;
+
+        JavaIterator() {
+            rawIterator = RubySortedSet.this.order.iterator();
+        }
+
+        @Override
+        public boolean hasNext() {
+            return rawIterator.hasNext();
+        }
+
+        @Override
+        public Object next() {
+            return rawIterator.next().toJava(Object.class);
+        }
+
+        @Override
+        public void remove() {
+            rawIterator.remove();
+        }
+
+    }
+
+}
diff --git a/core/src/main/java/org/jruby/ext/set/SetLibrary.java b/core/src/main/java/org/jruby/ext/set/SetLibrary.java
@@ -0,0 +1,45 @@
+/***** BEGIN LICENSE BLOCK *****
+ * Version: EPL 1.0/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Eclipse Public
+ * License Version 1.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * Copyright (C) 2016 Karol Bucek
+ * 
+ * Alternatively, the contents of this file may be used under the terms of
+ * either of the GNU General Public License Version 2 or later (the "GPL"),
+ * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the EPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the EPL, the GPL or the LGPL.
+ ***** END LICENSE BLOCK *****/
+package org.jruby.ext.set;
+
+import org.jruby.Ruby;
+import org.jruby.runtime.load.Library;
+
+public final class SetLibrary implements Library {
+
+    public void load(Ruby runtime, boolean wrap) {
+        SetLibrary.load(runtime);
+    }
+
+    public static void load(Ruby runtime) {
+        RubySet.createSetClass(runtime);
+        RubySortedSet.createSortedSetClass(runtime);
+        runtime.getModule("Enumerable").defineAnnotatedMethods(EnumerableExt.class);
+    }
+
+}
diff --git a/core/src/main/ruby/jruby/set.rb b/core/src/main/ruby/jruby/set.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+#
+# .rb part for JRuby's native Set impl (taken from set.rb)
+
+class Set
+
+  def pretty_print(pp)  # :nodoc:
+    pp.text sprintf('#<%s: {', self.class.name)
+    pp.nest(1) {
+      pp.seplist(self) { |o|
+        pp.pp o
+      }
+    }
+    pp.text '}>'
+  end
+
+  def pretty_print_cycle(pp)    # :nodoc:
+    pp.text sprintf('#<%s: {%s}>', self.class.name, empty? ? '' : '...')
+  end
+
+end
diff --git a/spec/ruby/library/set/sortedset/add_spec.rb b/spec/ruby/library/set/sortedset/add_spec.rb
@@ -7,9 +7,13 @@
 
   it "takes only values which responds <=>" do
     obj = mock('no_comparison_operator')
-    obj.should_receive(:respond_to?).with(:<=>).and_return(false)
+    obj.stub!(:respond_to?).with(:<=>).and_return(false)
     lambda { SortedSet["hello"].add(obj) }.should raise_error(ArgumentError)
   end
+
+  it "raises on incompatible <=> comparison" do
+    lambda { SortedSet['1', '2'].add(3) }.should raise_error(ArgumentError)
+  end
 end
 
 describe "SortedSet#add?" do

diff --git a/spec/ruby/library/set/sortedset/initialize_spec.rb b/spec/ruby/library/set/sortedset/initialize_spec.rb
@@ -21,4 +21,8 @@
     s.should include(4)
     s.should include(9)
   end
+
+  it "raises on incompatible <=> comparison" do
+    lambda { SortedSet.new(['00', nil]) }.should raise_error(ArgumentError)
+  end
 end
diff --git a/spec/ruby/library/set/sortedset/to_a_spec.rb b/spec/ruby/library/set/sortedset/to_a_spec.rb
@@ -2,7 +2,16 @@
 require 'set'
 
 describe "SortedSet#to_a" do
-  it "returns an array containing elements of self" do
-    SortedSet[1, 2, 3].to_a.sort.should == [1, 2, 3]
+  it "returns an array containing elements" do
+    set = SortedSet.new [1, 2, 3]
+    set.to_a.should == [1, 2, 3]
+  end
+
+  it "returns a sorted array containing elements" do
+    set = SortedSet[2, 3, 1]
+    set.to_a.should == [1, 2, 3]
+
+    set = SortedSet.new [5, 6, 4, 4]
+    set.to_a.should == [4, 5, 6]
   end
 end
diff --git a/test/jruby/test_set.rb b/test/jruby/test_set.rb
@@ -0,0 +1,121 @@
+require 'test/unit'
+require 'set.rb'
+
+# JRuby's Set impl specific or low-level details.
+class TestSet < Test::Unit::TestCase
+
+  class SubSet < Set ; end
+  class SubSortedSet < SortedSet ; end
+
+  def test_sub_set
+    set = SubSet.new
+    assert_same SubSet, set.class
+    assert set.is_a?(SubSet)
+    assert set.is_a?(Set)
+    assert hash = set.instance_variable_get(:@hash)
+    assert hash.is_a?(Hash)
+    assert_equal Hash.new, hash
+    assert_equal '#<TestSet::SubSet: {}>', set.inspect
+
+    assert_false Set.new.equal?(SubSet.new)
+    assert_true Set.new.eql?(SubSet.new)
+    assert_true ( SubSet.new == Set.new )
+
+    assert_false SortedSet.new.equal?(SubSortedSet.new)
+    assert_true SortedSet.new.eql?(SubSortedSet.new)
+    assert_true ( SubSortedSet.new == Set.new )
+    assert_true ( SubSortedSet.new == SortedSet.new )
+    assert_true ( SortedSet.new == SubSortedSet.new )
+  end
+
+  def test_allocate
+    set = Set.allocate
+    assert_same Set, set.class
+    assert_nil set.instance_variable_get(:@hash) # same on MRI
+
+    # set not really usable :
+    begin
+      set << 1 ; fail 'set << 1 did not fail!'
+    rescue # NoMethodError # JRuby: NPE
+      # NoMethodError: undefined method `[]=' for nil:NilClass
+      #   from /opt/local/rvm/rubies/ruby-2.3.3/lib/ruby/2.3.0/set.rb:313:in `add'
+    end
+  end
+
+  def test_marshal_dump
+    assert_equal "\x04\b{\x00".force_encoding('ASCII-8BIT'), Marshal.dump(Hash.new)
+
+    # MRI internally uses a @hash with a default: `Hash.new(false)'
+    empty_set = "\x04\bo:\bSet\x06:\n@hash}\x00F".force_encoding('ASCII-8BIT')
+    assert_equal empty_set, Marshal.dump(Set.new)
+
+    dump = Marshal.dump(Set.new)
+    assert_equal Set.new, Marshal.load(dump)
+
+    set = Marshal.load Marshal.dump(Set.new([1, 2]))
+    assert_same Set, set.class
+    assert_equal Set.new([1, 2]), set
+    set << 3
+    assert_equal 3, set.size
+
+    set = Marshal.load Marshal.dump(Set.new([1, 2]).dup)
+    assert_same Set, set.class
+    assert_equal Set.new([1, 2]), set
+  end
+
+  def test_sorted_marshal_dump
+    dump = Marshal.dump(SortedSet.new)
+    assert_equal SortedSet.new, Marshal.load(dump)
+
+    set = Marshal.load Marshal.dump(SortedSet.new([2, 1]))
+    assert_same SortedSet, set.class
+    assert_equal SortedSet.new([1, 2]), set
+    assert_equal [1, 2], set.sort
+    set << 3
+    assert_equal 3, set.size
+    assert_equal [1, 2, 3], set.sort
+
+    set = Marshal.load Marshal.dump(SortedSet.new([2, 1]).dup)
+    assert_same SortedSet, set.class
+    assert_equal SortedSet.new([1, 2]), set
+    assert_equal [1, 2], set.to_a
+
+    set = Marshal.load Marshal.dump(SortedSet.new([2, 3, 1]))
+    each = []; set.each { |e| each << e }
+    assert_equal [1, 2, 3], each
+  end
+
+  def test_dup
+    set = Set.new [1, 2]
+    assert_same Set, set.dup.class
+    assert_equal set, set.dup
+    dup = set.dup
+    set << 3
+    assert_equal 3, set.size
+    assert_equal 2, dup.size
+
+    set = SortedSet.new [1, 2]
+    assert_same SortedSet, set.dup.class
+    assert_equal set, set.dup
+    dup = set.dup
+    set << 0
+    assert_equal 3, set.size
+    assert_equal 2, dup.size
+  end
+
+  def test_to_java
+    assert set = Set.new.to_java
+    assert set.toString.start_with?('#<Set:0x')
+    assert_equal org.jruby.ext.set.RubySet, set.class
+    assert set.is_a?(java.util.Set)
+    assert_equal java.util.HashSet.new, set
+
+    assert set = SortedSet.new([2, 1]).to_java
+    assert set.toString.start_with?('#<SortedSet:0x')
+    assert_equal org.jruby.ext.set.RubySortedSet, set.class
+    assert set.is_a?(java.util.Set)
+    assert set.is_a?(java.util.SortedSet)
+    assert_equal java.util.TreeSet.new([1, 2]), set
+  end if defined? JRUBY_VERSION
+
+end