Add support for Array subclass methods to return Array

Author: Sergey Fedorov

spec/truffleruby.mspec

@@ -100,6 +100,13 @@ class MSpecScript
     spec/ruby/core/module/attr_reader_spec.rb
     spec/ruby/core/module/attr_writer_spec.rb
     spec/ruby/core/module/attr_accessor_spec.rb
+    spec/ruby/core/array/drop_spec.rb
+    spec/ruby/core/array/drop_while_spec.rb
+    spec/ruby/core/array/take_spec.rb
+    spec/ruby/core/array/take_while_spec.rb
+    spec/ruby/core/array/uniq_spec.rb
+    spec/ruby/core/array/multiply_spec.rb
+    spec/ruby/core/array/slice_spec.rb
   ]
 
   set :tags_patterns, [

src/main/java/org/truffleruby/core/array/ArrayIndexNodes.java

@@ -13,7 +13,6 @@
 import org.truffleruby.builtins.Primitive;
 import org.truffleruby.builtins.PrimitiveArrayArgumentsNode;
 import org.truffleruby.core.array.library.ArrayStoreLibrary;
-import org.truffleruby.core.klass.RubyClass;
 import org.truffleruby.language.RubyContextSourceNode;
 import org.truffleruby.language.RubyNode;
 
@@ -123,17 +122,16 @@ protected RubyArray readInBounds(RubyArray array, int index, int length,
                     ? length
                     : size - index;
             final Object slice = cowNode.execute(array, index, end);
-            return createArrayOfSameClass(array, slice, end);
+            return createArray(array, slice, end);
         }
 
         protected static boolean indexInBounds(RubyArray array, int index) {
             return index >= 0 && index <= array.size;
         }
 
-        protected RubyArray createArrayOfSameClass(RubyArray array, Object store, int size) {
-            final RubyClass logicalClass = array.getLogicalClass();
+        protected RubyArray createArray(RubyArray array, Object store, int size) {
             RubyArray newArray = new RubyArray(
-                    logicalClass,
+                    coreLibrary().arrayClass,
                     getLanguage().arrayShape,
                     store,
                     size);

src/main/java/org/truffleruby/core/array/ArrayNodes.java

@@ -163,9 +163,8 @@ public abstract static class MulNode extends PrimitiveArrayArgumentsNode {
 
         @Specialization(guards = "count == 0")
         protected RubyArray mulZero(RubyArray array, int count) {
-            final RubyClass logicalClass = array.getLogicalClass();
             return new RubyArray(
-                    logicalClass,
+                    coreLibrary().arrayClass,
                     getLanguage().arrayShape,
                     ArrayStoreLibrary.INITIAL_STORE,
                     0);
@@ -197,9 +196,8 @@ protected RubyArray mulOther(RubyArray array, int count,
                 profileAndReportLoopCount(loopProfile, n);
             }
 
-            final RubyClass logicalClass = array.getLogicalClass();
             return new RubyArray(
-                    logicalClass,
+                    coreLibrary().arrayClass,
                     getLanguage().arrayShape,
                     newStore,
                     newSize);
@@ -217,9 +215,8 @@ protected RubyArray mulLong(RubyArray array, long count) {
 
         @Specialization(guards = { "isEmptyArray(array)" })
         protected RubyArray mulEmpty(RubyArray array, long count) {
-            final RubyClass logicalClass = array.getLogicalClass();
             return new RubyArray(
-                    logicalClass,
+                    coreLibrary().arrayClass,
                     getLanguage().arrayShape,
                     ArrayStoreLibrary.INITIAL_STORE,
                     0);

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

@@ -109,6 +109,7 @@ def <=>(other)
 
   def *(count)
     result = Primitive.array_mul(self, count)
+
     if !Primitive.undefined?(result)
       result
     elsif str = Truffle::Type.rb_check_convert_type(count, String, :to_str)
@@ -443,9 +444,9 @@ def first(n = undefined)
 
   def flatten(level=-1)
     level = Primitive.rb_num2int level
-    return self.dup if level == 0
+    return Array.new(self) if level == 0
 
-    out = self.class.allocate # new_reserved size
+    out = [] # new_reserved size
     Primitive.array_flatten_helper(self, out, level)
     out
   end
@@ -1591,13 +1592,6 @@ def delete_range(index, del_length)
   end
   private :delete_range
 
-  def uniq(&block)
-    copy_of_same_class = dup
-    result = super(&block)
-    Primitive.steal_array_storage(copy_of_same_class, result)
-    copy_of_same_class
-  end
-
   def uniq!(&block)
     Primitive.check_frozen self
     result = uniq(&block)

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

@@ -1037,6 +1037,7 @@ class Array
   alias_method :take, :take
   alias_method :drop_while, :drop_while
   alias_method :take_while, :take_while
+  alias_method :uniq, :uniq
   alias_method :sum, :sum
   alias_method :all?, :all?
   alias_method :none?, :none?