Parse double-quoted string literals

Parser.Tests/MParserShould.cs

@@ -427,5 +427,17 @@ namespace Parser.Tests
             Assert.AreEqual("a", (e.Operand as IdentifierNameNode)?.Token.PureToken.LiteralText);
             Assert.AreEqual(text, actual.FullText);
         }
+
+        [Test]
+        public void ParseDoubleQuotedStringLiteral()
+        {
+            var text = "\"some string\"";
+            var sut = CreateParser(text);
+            var actual = sut.ParseExpression();
+            Assert.IsInstanceOf<DoubleQuotedStringLiteralNode>(actual);
+            var s = (DoubleQuotedStringLiteralNode) actual;
+            Assert.AreEqual("some string", s.Token.PureToken.Value);
+            Assert.AreEqual(text, actual.FullText);
+        }
     }
 }

Parser/MParser.cs

@@ -456,6 +456,11 @@ namespace Parser
                 var str = EatToken();
                 expression = Factory.StringLiteral(str);
             }
+            else if (token.Kind == TokenKind.DoubleQuotedStringLiteral)
+            {
+                var str = EatToken();
+                expression = Factory.DoubleQuotedStringLiteral(str);
+            }
             else if (token.Kind == TokenKind.OpeningSquareBracket) // array literal expression
             {
                 expression = ParseArrayLiteral();

Parser/SyntaxFactory.cs

@@ -245,6 +245,12 @@ namespace Parser
             return new StringLiteralNode(stringLiteral);
         }
 
+        public DoubleQuotedStringLiteralNode DoubleQuotedStringLiteral(
+            Token stringLiteral)
+        {
+            return new DoubleQuotedStringLiteralNode(stringLiteral);
+        }
+
         public ExpressionStatementNode ExpressionStatement(ExpressionNode expression)
         {
             var children = new List<SyntaxNode> {expression};

Parser/SyntaxNode.cs

@@ -315,6 +315,23 @@ namespace Parser
 
     }
 
+    public class DoubleQuotedStringLiteralNode : ExpressionNode
+    {
+        public Token Token { get; }
+
+        public DoubleQuotedStringLiteralNode(Token token) : base(null)
+        {
+            Token = token;
+        }
+
+        public override string FullText => Token.FullText;
+
+        public override IEnumerable<Token> ChildTokens
+        {
+            get { yield return Token; }
+        }
+    }
+
     public class StatementNode : SyntaxNode
     {
         public TokenNode SemicolonOrComma { get; set; }