enumerator.c: lazy_grep_v

* enumerator.c (lazy_grep_v): add Enumerator::Lazy#grep_v as well
  as Enumerable, to enumerate lazily.
  [ruby-core:71845] [Feature #11773]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52943 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 70 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index acf88edc08..f8e3668ac5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Tue Dec  8 16:23:40 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* enumerator.c (lazy_grep_v): add Enumerator::Lazy#grep_v as well
+	  as Enumerable, to enumerate lazily.
+	  [ruby-core:71845] [Feature #11773]
+
 Tue Dec  8 14:27:07 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* error.c (name_err_local_variables): new method
diff --git a/enumerator.c b/enumerator.c
index 092e950ec5..141496112f 100644
--- a/enumerator.c
+++ b/enumerator.c
@@ -1423,7 +1423,7 @@ lazy_set_method(VALUE lazy, VALUE args, rb_enumerator_size_func *size_fn)
  *   e.lazy -> lazy_enumerator
  *
  * Returns a lazy enumerator, whose methods map/collect,
- * flat_map/collect_concat, select/find_all, reject, grep, zip, take,
+ * flat_map/collect_concat, select/find_all, reject, grep, grep_v, zip, take,
  * take_while, drop, and drop_while enumerate values only on an
  * as-needed basis.  However, if a block is given to zip, values
  * are enumerated immediately.
@@ -1691,6 +1691,40 @@ lazy_grep(VALUE obj, VALUE pattern)
 }
 
 static VALUE
+lazy_grep_v_func(RB_BLOCK_CALL_FUNC_ARGLIST(val, m))
+{
+    VALUE i = rb_enum_values_pack(argc - 1, argv + 1);
+    VALUE result = rb_funcall(m, id_eqq, 1, i);
+
+    if (!RTEST(result)) {
+	rb_funcall(argv[0], id_yield, 1, i);
+    }
+    return Qnil;
+}
+
+static VALUE
+lazy_grep_v_iter(RB_BLOCK_CALL_FUNC_ARGLIST(val, m))
+{
+    VALUE i = rb_enum_values_pack(argc - 1, argv + 1);
+    VALUE result = rb_funcall(m, id_eqq, 1, i);
+
+    if (!RTEST(result)) {
+	rb_funcall(argv[0], id_yield, 1, rb_yield(i));
+    }
+    return Qnil;
+}
+
+static VALUE
+lazy_grep_v(VALUE obj, VALUE pattern)
+{
+    return lazy_set_method(rb_block_call(rb_cLazy, id_new, 1, &obj,
+					 rb_block_given_p() ?
+					 lazy_grep_v_iter : lazy_grep_v_func,
+					 pattern),
+			   rb_ary_new3(1, pattern), 0);
+}
+
+static VALUE
 call_next(VALUE obj)
 {
     return rb_funcall(obj, id_next, 0);
@@ -2029,6 +2063,7 @@ InitVM_Enumerator(void)
     rb_define_method(rb_cLazy, "find_all", lazy_select, 0);
     rb_define_method(rb_cLazy, "reject", lazy_reject, 0);
     rb_define_method(rb_cLazy, "grep", lazy_grep, 1);
+    rb_define_method(rb_cLazy, "grep_v", lazy_grep_v, 1);
     rb_define_method(rb_cLazy, "zip", lazy_zip, -1);
     rb_define_method(rb_cLazy, "take", lazy_take, 1);
     rb_define_method(rb_cLazy, "take_while", lazy_take_while, 0);
diff --git a/test/ruby/test_lazy_enumerator.rb b/test/ruby/test_lazy_enumerator.rb
index 952a773d58..a0c5068710 100644
--- a/test/ruby/test_lazy_enumerator.rb
+++ b/test/ruby/test_lazy_enumerator.rb
@@ -197,6 +197,34 @@ class TestLazyEnumerator < Test::Unit::TestCase
                  e.lazy.grep(proc {|x| x == [2, "2"]}, &:join).force)
   end
 
+  def test_grep_v
+    a = Step.new('a'..'f')
+    assert_equal('b', a.grep_v(/a/).first)
+    assert_equal('f', a.current)
+    assert_equal('a', a.lazy.grep_v(/c/).first)
+    assert_equal('a', a.current)
+    assert_equal(%w[b c d f], a.grep_v(proc {|x| /[aeiou]/ =~ x}))
+    assert_equal(%w[b c d f], a.lazy.grep_v(proc {|x| /[aeiou]/ =~ x}).to_a)
+  end
+
+  def test_grep_v_with_block
+    a = Step.new('a'..'f')
+    assert_equal('B', a.grep_v(/a/) {|i| i.upcase}.first)
+    assert_equal('B', a.lazy.grep_v(/a/) {|i| i.upcase}.first)
+  end
+
+  def test_grep_v_multiple_values
+    e = Enumerator.new { |yielder|
+      3.times { |i|
+        yielder.yield(i, i.to_s)
+      }
+    }
+    assert_equal([[0, "0"], [1, "1"]], e.grep_v(proc {|x| x == [2, "2"]}))
+    assert_equal([[0, "0"], [1, "1"]], e.lazy.grep_v(proc {|x| x == [2, "2"]}).force)
+    assert_equal(["00", "11"],
+                 e.lazy.grep_v(proc {|x| x == [2, "2"]}, &:join).force)
+  end
+
   def test_zip
     a = Step.new(1..3)
     assert_equal([1, "a"], a.zip("a".."c").first)