使 CommonMark.Net 支持 Table 解析

参照 为 CommonMark.Net 增加 Table 解析 增加了 CommonMark.Net 对表格的支持。下面是原文中的代码：

1. 为 Inline 增加一个类型 Table

   public enum InlineTag : byte
   {
       String = 0,
       SoftBreak,
       LineBreak,
       Code,
       RawHtml,
       Emphasis,
       Strong,
       Link,
       Image,
       Strikethrough,
       Table    //新增的 Table 类型
   }

2. 为 ‘|’ 符号增加处理方法

   internal static Func<Subject, Inline>[] InitializeParsers(CommonMarkSettings settings)
   {
       var strikethroughTilde = 0 != (settings.AdditionalFeatures & CommonMarkAdditionalFeatures.StrikethroughTilde);
   
       var p = new Func<Subject, Inline>[strikethroughTilde ? 127 : 125];
       p['\n'] = handle_newline;
       p['`'] = handle_backticks;
       p['\\'] = handle_backslash;
       p['&'] = HandleEntity;
       p['<'] = handle_pointy_brace;
       p['_'] = HandleEmphasis;
       p['*'] = HandleEmphasis;
       p['['] = HandleLeftSquareBracket;
       p[']'] = HandleRightSquareBracket;
       p['!'] = HandleExclamation;
       p['|'] = HandleTable;    //增加'|'的解析方法，把 | 到 | 封装为一个 Table 类型的 Inline
   
       if (strikethroughTilde)
           p['~'] = HandleTilde;
   
       return p;
   }
   
   private static Inline HandleTable(Subject subj)
   {
       //这里偷懒了，可以加个校验，确定是个 table，否则单个'|'也会被解析
       var start = subj.Buffer.IndexOf('|');
       var last = subj.Buffer.LastIndexOf('|');
       var inlTab = new Inline(InlineTag.Table, subj.Buffer.Substring(start, last - start + 1));
       subj.Position = last + 1;
       return inlTab;
   }

3. Table 类型 Inline 的渲染,InlinesToHtml

   switch (inline.Tag)
   {
       case InlineTag.Table:
           //tab
           writer.WriteConstant("<table class=\"table table-bordered table-striped\">");
           var lines = inline.LiteralContentValue.ToString().Split(new char[] { '\n' }, System.StringSplitOptions.RemoveEmptyEntries);
           int i = 0;
           foreach (var line in lines)
           {
               i++;
   
               if (line.Split(new char[] { '|', '-', ' ', '\n' }, System.StringSplitOptions.RemoveEmptyEntries).Length == 0)
               {
                   continue;
               }
   
               writer.WriteConstant("<tr>");
               var tds = line.Split(new char[] { '|' });
               for (int j = 1; j < tds.Length - 1; j++)
               {
                   writer.WriteConstant(i == 1 ? "<th>" : "<td>");
                   writer.WriteConstant(tds[j]);
                   writer.WriteConstant(i == 1 ? "</th>" : "</td>");
               }
               writer.WriteConstant("</tr>");
           }
           writer.WriteConstant("</table>");
           break;
           ....... ......
   }