enum.c: Enumerable#uniq

* enum.c (enum_uniq): new method Enumerable#uniq.
  [Feature #11090]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55709 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Wed Jul 20 17:39:11 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* enum.c (enum_uniq): new method Enumerable#uniq.
+	  [Feature #11090]
+
 Wed Jul 20 17:35:23 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* hash.c (rb_hash_add_new_element): add new element or do nothing

enum.c

@@ -3793,6 +3793,40 @@ enum_sum(int argc, VALUE* argv, VALUE obj)
     }
 }
 
+static VALUE
+uniq_func(RB_BLOCK_CALL_FUNC_ARGLIST(i, hash))
+{
+    rb_hash_add_new_element(hash, i, i);
+    return Qnil;
+}
+
+static VALUE
+uniq_iter(RB_BLOCK_CALL_FUNC_ARGLIST(i, hash))
+{
+    rb_hash_add_new_element(hash, rb_yield_values2(argc, argv), i);
+    return Qnil;
+}
+
+/*
+ *  call-seq:
+ *     enum.uniq                -> new_ary
+ *     enum.uniq { |item| ... } -> new_ary
+ */
+
+static VALUE
+enum_uniq(VALUE obj)
+{
+    VALUE hash, ret;
+    rb_block_call_func *const func =
+	rb_block_given_p() ? uniq_iter : uniq_func;
+
+    hash = rb_obj_hide(rb_hash_new());
+    rb_block_call(obj, id_each, 0, 0, func, hash);
+    ret = rb_hash_values(hash);
+    rb_hash_clear(hash);
+    return ret;
+}
+
 /*
  *  The <code>Enumerable</code> mixin provides collection classes with
  *  several traversal and searching methods, and with the ability to
@@ -3866,6 +3900,7 @@ Init_Enumerable(void)
     rb_define_method(rb_mEnumerable, "slice_when", enum_slice_when, 0);
     rb_define_method(rb_mEnumerable, "chunk_while", enum_chunk_while, 0);
     rb_define_method(rb_mEnumerable, "sum", enum_sum, -1);
+    rb_define_method(rb_mEnumerable, "uniq", enum_uniq, 0);
 
     id_next = rb_intern("next");
     id_call = rb_intern("call");

test/ruby/test_enum.rb

@@ -921,4 +921,19 @@ class TestEnumerable < Test::Unit::TestCase
     assert_int_equal(2, (2..2).sum)
     assert_int_equal(42, (2...2).sum(42))
   end
+
+  def test_uniq
+    src = [1, 1, 1, 1, 2, 2, 3, 4, 5, 6]
+    assert_equal([1, 2, 3, 4, 5, 6], src.uniq.to_a)
+    olimpics = {
+      1896 => 'Athens',
+      1900 => 'Paris',
+      1904 => 'Chikago',
+      1906 => 'Athens',
+      1908 => 'Rome',
+    }
+    assert_equal([[1896, "Athens"], [1900, "Paris"], [1904, "Chikago"], [1908, "Rome"]],
+                 olimpics.uniq{|k,v| v})
+    assert_equal([1, 2, 3, 4, 5, 10], (1..100).uniq{|x| (x**2) % 10 }.first(6))
+  end
 end