Fix error when character after string end

Upsilon/BaseTypes/LuaString.cs

@@ -31,10 +31,9 @@ namespace Upsilon.BaseTypes
             return (Value != null ? Value.GetHashCode() : 0);
         }
 
-        public bool Equals(LuaString s)
+        private bool Equals(LuaString s)
         {
-            if (s == null) return false;
-            return string.Equals(s.Value, Value);
+            return s != null && string.Equals(s.Value, Value);
         }
 
         public static LuaString operator +(LuaString a, LuaType b)

Upsilon/Parser/Lexer.cs

@@ -141,7 +141,7 @@ namespace Upsilon.Parser
         {
             var start = _position;
             var sb = new StringBuilder();
-            while (true)
+            while (_position < _text.Length)
             {
                 _position++;
                 if (Current == '"')
@@ -149,8 +149,6 @@ namespace Upsilon.Parser
                 sb.Append(Current);
             }
 
-            _position++;
-
             var res = sb.ToString();
             return new SyntaxToken(SyntaxKind.String, start, $"\"{res}\"", res);
         }