LINQPad query to convert HTML table into a normalized textual tree

htmltbl2tt.linq

<Query Kind="Program">
  <Reference>&lt;RuntimeDirectory&gt;\System.Net.Http.dll</Reference>
  <NuGetReference>Fizzler.Systems.HtmlAgilityPack</NuGetReference>
  <NuGetReference Prerelease="true">WebLinq</NuGetReference>
  <Namespace>Fizzler</Namespace>
  <Namespace>Fizzler.Systems.HtmlAgilityPack</Namespace>
  <Namespace>HtmlAgilityPack</Namespace>
  <Namespace>System.Net.Http</Namespace>
  <Namespace>System.Threading.Tasks</Namespace>
  <Namespace>WebLinq.Html</Namespace>
</Query>

async Task Main(string[] args)
{
    var url = args != null && args.Any()
            ? new Uri(args.First())
            : new Uri("https://en.wikipedia.org/wiki/Queen_discography");
            
    string html;
    using (var http = new HttpClient())
        html = await http.GetStringAsync(url);
        
    const string space = "\x20";
    const string indent = space + space;

    var tree =
        from t in new HapHtmlParser().Parse(html, null).Tables(null)
        let id = t.GetAttributeValue("id")
        from ss in new[]
        {
            new[] { "- TABLE" + (string.IsNullOrEmpty(id) ? id : "#" + id) },
            from row in
                t.TableRows((_, tds) => from td in tds
                                        select td?.InnerText ?? "<NULL>" into s
                                        select Regex.Replace(s, @"\r|\n", " ") into s
                                        select Regex.Replace(s, @"\s{2,}", " ") into s
                                        select s.Trim())
            from ss in new[]
            {
                new[] { indent + "- ROW" },
                from cell in row
                select indent + indent + "- " + cell
            }
            from s in ss
            select s
        }
        from s in ss
        select s;

    foreach (var e in tree)
        Console.WriteLine(e);
}