pixie.cs

namespace ConsoleApp9
{
    using System;
    using Pixie;
    using Pixie.Code;
    using Pixie.Markup;
    using Pixie.Terminal;
    using Pixie.Terminal.Render;
    using Pixie.Transforms;

    class Program
    {
        private static LogEntry MakeDiagnostic(LogEntry entry)
        {
            return DiagnosticExtractor.Transform(entry, new Text("program"));
        }

        private const string SourceCode = @"public static class Program
{

    public Program()
    { 
    
    }

}";
        static void Main(string[] args)
        {
            ILog log = TerminalLog
                .Acquire()
                .WithRenderers(new NodeRenderer[]
                {
                    new HighlightedSourceRenderer(5)
                });

            log = new TransformLog(
                log,
                new Func<LogEntry, LogEntry>[]
                {
                    MakeDiagnostic
                });

            var doc = new StringDocument("code.cs", SourceCode);
            var ctorStartOffset = SourceCode.IndexOf("public Program()", StringComparison.InvariantCulture);
            var ctorNameOffset = SourceCode.IndexOf("Program()", StringComparison.InvariantCulture);

            var highlightRegion = new SourceRegion(
                    new SourceSpan(doc, ctorStartOffset, "public Program()".Length))
                .ExcludeCharacters(char.IsWhiteSpace);

            var focusRegion = new SourceRegion(
                new SourceSpan(doc, ctorNameOffset, "Program".Length));

            log.Log(
                new LogEntry(
                    Severity.Error,
                    "hello world",
                    new MarkupNode[]
                    {
                        new Text("look at this beautiful error message!"),
                        new HighlightedSource(highlightRegion, focusRegion)
                    }));

            Console.ReadLine();
        }
    }
}