Changed some comments and reviewed the code.

Author: nikolovivan

Attributes/HtmlAttribute.cs

@@ -7,7 +7,7 @@
 namespace CodeTranslator.Attributes
 {
     /// <summary>
-    /// Represents a base class for the different attribute types.
+    /// Represents a class for an html attribute.
     /// </summary>
     public class HtmlAttribute
     {
@@ -56,11 +56,6 @@ public override bool Equals(object obj)
 
         public override int GetHashCode()
         {
-            //here I use the Name only, because:
-            //if we have two pairs of options:
-            //A(x)-B and A-B, where A(x) means only the option 'x' from attribute A and just A means the whole attribute value,
-            //we won't know which of them to use. We will have to add additional options, which I don't need right now.
-            //I need to use the value here!
             return Name.GetHashCode() ^ (Value != null ? Value.GetHashCode() : -1);
         }
 

Nodes/SyntaxNode.cs

@@ -13,7 +13,7 @@ public abstract class SyntaxNode
         /// <summary>
         /// The string which is used to replace the newline.
         /// </summary>
-        public string NewlineRepresentation { get; set; } //the set has to be public in order to be able to use it in derived classes        
+        public string NewlineRepresentation { get; set; }
         /// <summary>
         /// The list of the children nodes.
         /// </summary>

Parsers/BBCodeParser.cs

@@ -37,7 +37,6 @@ public string ToHtml(string bbcode)
         /// <param name="code">The bbcode</param> 
         protected override SyntaxNode ParseSyntaxNode(string code)
         {
-            //don't forget to take care for those tags where we don't want to parse the tags!!!
             if (string.IsNullOrEmpty(code)) throw new ArgumentNullException("code");
             Stack<SyntaxNode> syntaxStack = new Stack<SyntaxNode>(); //this is a stack that will hold the bbcode nodes.
             syntaxStack.Push(new BBCodeSyntaxNode(null, null)); //push the main node.

Tags/HtmlTag.cs

@@ -14,7 +14,7 @@ namespace CodeTranslator.Tags
     public class HtmlTag : Tag
     {
         /// <summary>
-        /// The string which is used to replace the new line in Html. It gets converted to /n in BBCode
+        /// The string which is used to replace the new line in Html. It gets converted to \n in BBCode
         /// </summary>
         public string NewlineReplacer { get; private set; }
         /// <summary>
@@ -36,19 +36,20 @@ public HtmlTag(string openHtmlTag, string closeHtmlTag, string newlineReplacer,
         /// <param name="tagOptions">The different possible options</param>
         protected override void ValidateOptions(TagOption[] tagOptions)
         {
-            if (tagOptions.Distinct().Count() != tagOptions.Length) throw new ArgumentException("All option values must be different!");
+            if (tagOptions.Distinct().Count() != tagOptions.Length) throw new ArgumentException("All option values must be unique!");
             if (tagOptions.FirstOrDefault(o => !(o is HtmlOption)) != null) throw new ArgumentException("All option values must be of type HtmlOption!");
         }
 
         /// <summary>
-        /// Returns true if the value written in the parameter is a valid tag. The results is produced for the whole tag.
+        /// Returns true if the value written in the parameter is a valid tag. The result is produced for the whole tag.
         /// </summary>
         /// <param name="tagValue">The tag value</param>
         public override bool IsValid(string tagValue)
         {
             if (string.IsNullOrEmpty(tagValue)) throw new ArgumentNullException("tagValue");
             tagValue = tagValue.Trim('<', '>'); //trim the open and close brackets
-            string tagName = tagValue.Contains(' ') ? tagValue.Substring(0, tagValue.IndexOf(' ')) : tagValue;//get the tag name (until the first space character or the whole string.)
+            //get the tag name (until the first space character if attributes are present or the whole string.)
+            string tagName = tagValue.Contains(' ') ? tagValue.Substring(0, tagValue.IndexOf(' ')) : tagValue;
             if (OpenTag != tagName)
             {
                 if (CloseTag == tagName) return true; //the close tag is always valid

Tags/Tag.cs

@@ -50,5 +50,9 @@ public Tag(string openTag, string closeTag, params TagOption[] tagOptions)
         /// </summary>
         /// <param name="tagValue">The tag value</param>
         public abstract bool IsValid(string tagValue);
+        /// <summary>
+        /// Returns the opposite representation - HTML for BBCode and vice versa.
+        /// </summary>
+        public abstract string ToOppositeRepresentation();
     }
 }