Loyc.Syntax.Les.Les3PrettyPrinter.PrintToHtmlCore C# (CSharp) Method

		public static StringBuilder PrintToHtmlCore(
				StringBuilder input, StringBuilder output = null, 
				bool addPreCode = true, string newline = "\n",
				string[] colorCodesToCssClasses = null)
		{
			CheckParam.Arg("output", output != input);
			colorCodesToCssClasses = colorCodesToCssClasses ?? DefaultCssClassTable;
			output = output ?? new StringBuilder(input.Length);
			if (addPreCode)
				output.Append("<pre class='highlight'><code>");

			string cssClass = null;
			int depth = 0;
			char c, next = input.TryGet(0, '\0');
			for (int i = 0; i < input.Length; i++) {
				c = next;
				next = input.TryGet(i + 1, '\0');
				if (c < colorCodesToCssClasses.Length) {
					if (c <= '\n') {        // \n is 10
						if (c == '\n') {
							output.Append(newline);
						} else if (c != '\0') {
							// If the LNode contains control codes, printer should have \escaped them
							Debug.Assert(c == '\t'); // \t is 9 
							output.Append(c);
						}
					} else if (c == (char)LesColorCode.Opener) {
						if (next == '(' || next == '[')
							c = (char)((++depth & 1) == 0 ? LesColorCode.Closer : LesColorCode.Opener);
						else
							c = (char)LesColorCode.Separator;
					} else if (c == (char)LesColorCode.Closer) {
						if (next == ')' || next == ']')
							c = (char)((--depth & 1) == 1 ? LesColorCode.Closer : LesColorCode.Opener);
						else
							c = (char)LesColorCode.Separator;
					}

					var newClass = colorCodesToCssClasses[(int)c];
					if (newClass != cssClass) {
						if (cssClass != null)
							output.Append("</span>");
						if (newClass != null)
							output.Append("<span class='").Append(newClass).Append("'>");
						cssClass = newClass;
					}
					if (c == (char)LesColorCode.Attribute && next == '@' && 
						input.TryGet(i + 2, '\0').IsOneOf((char)LesColorCode.Id, (char)LesColorCode.Number, (char)LesColorCode.KeywordLiteral, (char)LesColorCode.CustomLiteral, (char)LesColorCode.String))
					{
						output.Append('@');
						// skip over @ and the next control code to extend attribute coloring over it
						i += 2;
					}
				} else if (c == '<') {
					output.Append("&lt;");
				} else if (c == '&') {
					output.Append("&amp;");
				} else {
					output.Append(c);
				}
			}
			if (cssClass != null)
				output.Append("</span>");

			if (addPreCode)
				output.Append("</code></pre>");
			return output;
		}