Fix tag parsing with () (#532)

src/exp.h

@@ -135,7 +135,7 @@ inline const RegEx& URI() {
   return e;
 }
 inline const RegEx& Tag() {
-  static const RegEx e = Word() || RegEx("#;/?:@&=+$_.~*'", REGEX_OR) ||
+  static const RegEx e = Word() || RegEx("#;/?:@&=+$_.~*'()", REGEX_OR) ||
                          (RegEx('%') + Hex() + Hex());
   return e;
 }
@@ -200,7 +200,7 @@ inline const RegEx& Chomp() {
 
 // and some functions
 std::string Escape(Stream& in);
-}
+}  // namespace Exp
 
 namespace Keys {
 const char Directive = '%';
@@ -216,7 +216,7 @@ const char LiteralScalar = '|';
 const char FoldedScalar = '>';
 const char VerbatimTagStart = '<';
 const char VerbatimTagEnd = '>';
-}
-}
+}  // namespace Keys
+}  // namespace YAML
 
 #endif  // EXP_H_62B23520_7C8E_11DE_8A39_0800200C9A66

test/integration/load_node_test.cpp

@@ -230,6 +230,12 @@ TEST(NodeTest, LoadTildeAsNull) {
   Node node = Load("~");
   ASSERT_TRUE(node.IsNull());
 }
+    
+TEST(NodeTest, LoadTagWithParenthesis) {
+    Node node = Load("!Complex(Tag) foo");
+    EXPECT_EQ(node.Tag(), "!Complex(Tag)");
+    EXPECT_EQ(node.as<std::string>(), "foo");
+}
 
 }  // namespace
 }  // namespace YAML