Simple VSIX test for VS2012

using Microsoft.VisualStudio.Language.StandardClassification;
using Microsoft.VisualStudio.Text;
using Microsoft.VisualStudio.Text.Classification;
using Microsoft.VisualStudio.Utilities;
using System;
using System.Collections.Generic;
using System.ComponentModel.Composition;

namespace VSIXProject1
{
    internal static class MyLangLanguage
    {
        public const string ContentType = "mylang";

        public const string FileExtension = ".mylang";

        [Export(typeof(ClassificationTypeDefinition))]
        [Name(ContentType)]
        [BaseDefinition("code")]
        internal static ContentTypeDefinition MyLangSyntaxContentTypeDefinition = null;

        [Export]
        [FileExtension(FileExtension)]
        [ContentType(ContentType)]
        internal static FileExtensionToContentTypeDefinition MyLangSyntaxFileExtensionDefinition = null;
    }

    [Export(typeof(IClassifierProvider))]
    [ContentType(MyLangLanguage.ContentType)]
    [Name("MyLangSyntaxProvider")]
    internal sealed class MyLangSyntaxProvider : IClassifierProvider
    {
        [Import]
        internal IClassificationTypeRegistryService ClassificationRegistry = null;

        public IClassifier GetClassifier(ITextBuffer buffer)
        {
            return buffer.Properties.GetOrCreateSingletonProperty(() => new MyLangSyntax(ClassificationRegistry, buffer));
        }
    }

    internal sealed class MyLangSyntax : IClassifier
    {
        private ITextBuffer buffer;
        private IClassificationType identifierType;
        private IClassificationType keywordType;

        public event EventHandler<ClassificationChangedEventArgs> ClassificationChanged;

        internal MyLangSyntax(IClassificationTypeRegistryService registry, ITextBuffer buffer)
        {
            this.identifierType = registry.GetClassificationType(PredefinedClassificationTypeNames.Identifier);
            this.keywordType = registry.GetClassificationType(PredefinedClassificationTypeNames.Keyword);
            this.buffer = buffer;
            this.buffer.Changed += OnBufferChanged;
        }

        public IList<ClassificationSpan> GetClassificationSpans(SnapshotSpan snapshotSpan)
        {
            var classifications = new List<ClassificationSpan>();

            string text = snapshotSpan.GetText();
            var span = new SnapshotSpan(snapshotSpan.Snapshot, snapshotSpan.Start.Position, text.Length);
            classifications.Add(new ClassificationSpan(span, keywordType));

            return classifications;
        }

        private void OnBufferChanged(object sender, TextContentChangedEventArgs e)
        {
            foreach (var change in e.Changes)
                ClassificationChanged(this, new ClassificationChangedEventArgs(new SnapshotSpan(e.After, change.NewSpan)));
        }
    }
}