html_token_visitor.cs

csharp-solution,C#高效编程源码

namespace CSharp
{ 
    using System;
    
    public sealed class HTMLTokenVisitor : ITokenVisitor
    {
        // Add methods here

		private void SpannedFilteredWrite(string spanName, IToken token)
		{
			Console.Write("<span class=\"{0}\">", spanName);
			FilteredWrite(token);
			Console.Write("</span>");
		}

		private void FilteredWrite(IToken token)
		{
			string src = token.ToString();
			for (int i = 0; i != src.Length; i++) 
			{
				string dst;
				switch (src[i]) 
				{
					case '<' : dst = "&lt;"; break;
					case '>' : dst = "&gt;"; break;
					case '&' : dst = "&amp;"; break;
					default  : dst = new string(src[i], 1); break;
				}
				Console.Write(dst);
			}
		}

		public void Visit(ILineStartToken line)
		{
			Console.Write("<span class=\"line_number\">");
			Console.Write("{0,3}", line.Number());	
			Console.Write("</span>");
		}

		public void Visit(ILineEndToken t)
		{
			Console.WriteLine();
		}

		public void Visit(IIdentifierToken token)
		{
			SpannedFilteredWrite("identifier", token);
		}

		public void Visit(ICommentToken token)
		{
			SpannedFilteredWrite("comment", token);
		}

		public void Visit(IKeywordToken token)
		{
			SpannedFilteredWrite("keyword", token);
		}

		public void Visit(IWhiteSpaceToken token)
		{
			Console.Write(token.ToString());
		}

		public void Visit(IDirectiveToken token)
		{
			SpannedFilteredWrite("directive", token);
		}

		public void Visit(IOtherToken token)
		{
			FilteredWrite(token);
		}
    }
}