WIP

Directory.Packages.props

@@ -2,6 +2,7 @@
   <ItemGroup>
     <PackageVersion Include="BenchmarkDotNet" Version="$(BenchmarkDotNetVersion)" />
     <PackageVersion Include="Newtonsoft.Json" Version="$(NewtonsoftJsonVersion)" />
+    <PackageVersion Include="MessagePack.Annotations" Version="$(MessagePackAnnotationsVersion)" />
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="$(MicrosoftCodeAnalysisCSharpVersion)" />
     <PackageVersion Include="Microsoft.Extensions.DependencyModel" Version="$(MicrosoftExtensionsDependencyModelVersion)" />
     <PackageVersion Include="Moq" Version="$(MoqVersion)" />

eng/Versions.props

@@ -36,6 +36,7 @@
   -->
   <PropertyGroup Label="Manual">
     <BenchmarkDotNetVersion>0.13.0</BenchmarkDotNetVersion>
+    <MessagePackAnnotationsVersion>2.3.85</MessagePackAnnotationsVersion>
     <MicrosoftCodeAnalysisCSharpVersion>4.0.0-4.final</MicrosoftCodeAnalysisCSharpVersion>
     <MicrosoftExtensionsDependencyModelVersion>6.0.0</MicrosoftExtensionsDependencyModelVersion>
     <SystemDiagnosticsDiagnosticSourceVersion>6.0.0</SystemDiagnosticsDiagnosticSourceVersion>

src/Microsoft.AspNetCore.Razor.Internal.SourceGenerator.Transport/Microsoft.AspNetCore.Razor.Internal.SourceGenerator.Transport.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <Description>Transport package for Razor Source Generator support.</Description>
@@ -27,6 +27,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="MessagePack.Annotations" />
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" />
   </ItemGroup>
 

src/Microsoft.AspNetCore.Razor.Language/src/AllowedChildTagDescriptor.cs

@@ -4,15 +4,21 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using MessagePack;
 
 namespace Microsoft.AspNetCore.Razor.Language;
 
+[MessagePackObject]
+[Union(0, typeof(DefaultAllowedChildTagDescriptor))]
 public abstract class AllowedChildTagDescriptor : IEquatable<AllowedChildTagDescriptor>
 {
+    [Key(0)]
     public string Name { get; protected set; }
 
+    [Key(1)]
     public string DisplayName { get; protected set; }
 
+    [Key(2)]
     public IReadOnlyList<RazorDiagnostic> Diagnostics { get; protected set; }
 
     public bool HasErrors

src/Microsoft.AspNetCore.Razor.Language/src/BoundAttributeDescriptor.cs

@@ -4,12 +4,15 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using MessagePack;
 
 namespace Microsoft.AspNetCore.Razor.Language;
 
 /// <summary>
 /// A metadata class describing a tag helper attribute.
 /// </summary>
+[MessagePackObject]
+[Union(0, typeof(DefaultBoundAttributeDescriptor))]
 public abstract class BoundAttributeDescriptor : IEquatable<BoundAttributeDescriptor>
 {
     protected BoundAttributeDescriptor(string kind)
@@ -17,42 +20,61 @@ public abstract class BoundAttributeDescriptor : IEquatable<BoundAttributeDescri
         Kind = kind;
     }
 
+    [Key(0)]
     public string Kind { get; }
 
-    public bool IsIndexerStringProperty { get; protected set; }
-
-    public bool IsIndexerBooleanProperty { get; protected set; }
-
-    public bool IsEnum { get; protected set; }
-
-    public bool IsStringProperty { get; protected set; }
-
-    public bool IsBooleanProperty { get; protected set; }
-
-    internal bool IsEditorRequired { get; set; }
-
+    [Key(1)]
     public string Name { get; protected set; }
 
-    public string IndexerNamePrefix { get; protected set; }
-
+    [Key(2)]
     public string TypeName { get; protected set; }
 
-    public string IndexerTypeName { get; protected set; }
+    [Key(3)]
+    public bool IsEnum { get; protected set; }
 
+    [Key(4)]
     public bool HasIndexer { get; protected set; }
 
+    [Key(5)]
+    public string IndexerNamePrefix { get; protected set; }
+
+    [Key(6)]
+    public string IndexerTypeName { get; protected set; }
+
+    [Key(7)]
     public string Documentation { get; protected set; }
 
+    [Key(8)]
     public string DisplayName { get; protected set; }
 
+    [Key(9)]
     public bool CaseSensitive { get; protected set; }
 
-    public IReadOnlyList<RazorDiagnostic> Diagnostics { get; protected set; }
-
-    public IReadOnlyDictionary<string, string> Metadata { get; protected set; }
-
+    [Key(10)]
     public virtual IReadOnlyList<BoundAttributeParameterDescriptor> BoundAttributeParameters { get; protected set; }
 
+    [Key(11)]
+    public IReadOnlyDictionary<string, string> Metadata { get; protected set; }
+
+    [Key(12)]
+    public IReadOnlyList<RazorDiagnostic> Diagnostics { get; protected set; }
+
+    [IgnoreMember]
+    public bool IsIndexerStringProperty { get; protected set; }
+
+    [IgnoreMember]
+    public bool IsIndexerBooleanProperty { get; protected set; }
+
+    [IgnoreMember]
+    public bool IsStringProperty { get; protected set; }
+
+    [IgnoreMember]
+    public bool IsBooleanProperty { get; protected set; }
+
+    [IgnoreMember]
+    internal bool IsEditorRequired { get; set; }
+
+    [IgnoreMember]
     public bool HasErrors
     {
         get

src/Microsoft.AspNetCore.Razor.Language/src/BoundAttributeParameterDescriptor.cs

@@ -1,12 +1,15 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using MessagePack;
 
 namespace Microsoft.AspNetCore.Razor.Language;
 
+[MessagePackObject]
+[Union(0, typeof(DefaultBoundAttributeParameterDescriptor))]
 public abstract class BoundAttributeParameterDescriptor : IEquatable<BoundAttributeParameterDescriptor>
 {
     protected BoundAttributeParameterDescriptor(string kind)
@@ -14,28 +17,40 @@ public abstract class BoundAttributeParameterDescriptor : IEquatable<BoundAttrib
         Kind = kind;
     }
 
+    [Key(0)]
     public string Kind { get; }
 
-    public bool IsEnum { get; protected set; }
-
-    public bool IsStringProperty { get; protected set; }
-
-    public bool IsBooleanProperty { get; protected set; }
-
+    [Key(1)]
     public string Name { get; protected set; }
 
+    [Key(2)]
     public string TypeName { get; protected set; }
 
+    [Key(3)]
+    public bool IsEnum { get; protected set; }
+
+    [Key(4)]
     public string Documentation { get; protected set; }
 
+    [Key(5)]
     public string DisplayName { get; protected set; }
 
+    [Key(6)]
     public bool CaseSensitive { get; protected set; }
 
-    public IReadOnlyList<RazorDiagnostic> Diagnostics { get; protected set; }
-
+    [Key(7)]
     public IReadOnlyDictionary<string, string> Metadata { get; protected set; }
 
+    [Key(8)]
+    public IReadOnlyList<RazorDiagnostic> Diagnostics { get; protected set; }
+
+    [IgnoreMember]
+    public bool IsStringProperty { get; protected set; }
+
+    [IgnoreMember]
+    public bool IsBooleanProperty { get; protected set; }
+
+    [IgnoreMember]
     public bool HasErrors
     {
         get

src/Microsoft.AspNetCore.Razor.Language/src/DefaultBoundAttributeDescriptor.cs

@@ -2,11 +2,14 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Collections.Generic;
+using MessagePack;
 
 namespace Microsoft.AspNetCore.Razor.Language;
 
-internal sealed class DefaultBoundAttributeDescriptor : BoundAttributeDescriptor
+[MessagePackObject]
+public sealed class DefaultBoundAttributeDescriptor : BoundAttributeDescriptor
 {
+    [SerializationConstructor]
     public DefaultBoundAttributeDescriptor(
         string kind,
         string name,
@@ -18,9 +21,9 @@ internal sealed class DefaultBoundAttributeDescriptor : BoundAttributeDescriptor
         string documentation,
         string displayName,
         bool caseSensitive,
-        BoundAttributeParameterDescriptor[] parameterDescriptors,
-        Dictionary<string, string> metadata,
-        RazorDiagnostic[] diagnostics)
+        IReadOnlyList<BoundAttributeParameterDescriptor> parameterDescriptors,
+        IReadOnlyDictionary<string, string> metadata,
+        IReadOnlyList<RazorDiagnostic> diagnostics)
         : base(kind)
     {
         Name = name;

src/Microsoft.AspNetCore.Razor.Language/src/DefaultBoundAttributeParameterDescriptor.cs

@@ -1,12 +1,15 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Collections.Generic;
+using MessagePack;
 
 namespace Microsoft.AspNetCore.Razor.Language;
 
-internal class DefaultBoundAttributeParameterDescriptor : BoundAttributeParameterDescriptor
+[MessagePackObject]
+public class DefaultBoundAttributeParameterDescriptor : BoundAttributeParameterDescriptor
 {
+    [SerializationConstructor]
     public DefaultBoundAttributeParameterDescriptor(
         string kind,
         string name,
@@ -15,8 +18,8 @@ internal class DefaultBoundAttributeParameterDescriptor : BoundAttributeParamete
         string documentation,
         string displayName,
         bool caseSensitive,
-        Dictionary<string, string> metadata,
-        RazorDiagnostic[] diagnostics)
+        IReadOnlyDictionary<string, string> metadata,
+        IReadOnlyList<RazorDiagnostic> diagnostics)
         : base(kind)
     {
         Name = name;

src/Microsoft.AspNetCore.Razor.Language/src/DefaultRequiredAttributeDescriptor.cs

@@ -1,12 +1,15 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Collections.Generic;
+using MessagePack;
 
 namespace Microsoft.AspNetCore.Razor.Language;
 
-internal class DefaultRequiredAttributeDescriptor : RequiredAttributeDescriptor
+[MessagePackObject]
+public class DefaultRequiredAttributeDescriptor : RequiredAttributeDescriptor
 {
+    [SerializationConstructor]
     public DefaultRequiredAttributeDescriptor(
         string name,
         NameComparisonMode nameComparison,
@@ -14,8 +17,8 @@ internal class DefaultRequiredAttributeDescriptor : RequiredAttributeDescriptor
         string value,
         ValueComparisonMode valueComparison,
         string displayName,
-        RazorDiagnostic[] diagnostics,
-        Dictionary<string, string> metadata)
+        IReadOnlyDictionary<string, string> metadata,
+        IReadOnlyList<RazorDiagnostic> diagnostics)
     {
         Name = name;
         NameComparison = nameComparison;

src/Microsoft.AspNetCore.Razor.Language/src/DefaultRequiredAttributeDescriptorBuilder.cs

@@ -60,8 +60,8 @@ internal class DefaultRequiredAttributeDescriptorBuilder : RequiredAttributeDesc
             Value,
             ValueComparisonMode,
             displayName,
-            diagnostics?.ToArray() ?? Array.Empty<RazorDiagnostic>(),
-            new Dictionary<string, string>(Metadata));
+            new Dictionary<string, string>(Metadata),
+            diagnostics?.ToArray() ?? Array.Empty<RazorDiagnostic>());
 
         return rule;
     }

src/Microsoft.AspNetCore.Razor.Language/src/DefaultTagHelperDescriptor.cs

@@ -1,12 +1,15 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Collections.Generic;
+using MessagePack;
 
 namespace Microsoft.AspNetCore.Razor.Language;
 
-internal class DefaultTagHelperDescriptor : TagHelperDescriptor
+[MessagePackObject]
+public class DefaultTagHelperDescriptor : TagHelperDescriptor
 {
+    [SerializationConstructor]
     public DefaultTagHelperDescriptor(
         string kind,
         string name,
@@ -15,11 +18,11 @@ internal class DefaultTagHelperDescriptor : TagHelperDescriptor
         string documentation,
         string tagOutputHint,
         bool caseSensitive,
-        TagMatchingRuleDescriptor[] tagMatchingRules,
-        BoundAttributeDescriptor[] attributeDescriptors,
-        AllowedChildTagDescriptor[] allowedChildTags,
-        Dictionary<string, string> metadata,
-        RazorDiagnostic[] diagnostics)
+        IReadOnlyList<TagMatchingRuleDescriptor> tagMatchingRules,
+        IReadOnlyList<BoundAttributeDescriptor> attributeDescriptors,
+        IReadOnlyList<AllowedChildTagDescriptor> allowedChildTags,
+        IReadOnlyDictionary<string, string> metadata,
+        IReadOnlyList<RazorDiagnostic> diagnostics)
         : base(kind)
     {
         Name = name;

src/Microsoft.AspNetCore.Razor.Language/src/DefaultTagMatchingRuleDescriptor.cs

@@ -1,17 +1,22 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Collections.Generic;
+using MessagePack;
+
 namespace Microsoft.AspNetCore.Razor.Language;
 
-internal class DefaultTagMatchingRuleDescriptor : TagMatchingRuleDescriptor
+[MessagePackObject]
+public class DefaultTagMatchingRuleDescriptor : TagMatchingRuleDescriptor
 {
+    [SerializationConstructor]
     public DefaultTagMatchingRuleDescriptor(
         string tagName,
         string parentTag,
         TagStructure tagStructure,
         bool caseSensitive,
-        RequiredAttributeDescriptor[] attributes,
-        RazorDiagnostic[] diagnostics)
+        IReadOnlyList<RequiredAttributeDescriptor> attributes,
+        IReadOnlyList<RazorDiagnostic> diagnostics)
     {
         TagName = tagName;
         ParentTag = parentTag;

src/Microsoft.AspNetCore.Razor.Language/src/Microsoft.AspNetCore.Razor.Language.csproj

@@ -7,4 +7,8 @@
     <ExcludeFromSourceBuild>false</ExcludeFromSourceBuild>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="MessagePack.Annotations" />
+  </ItemGroup>
+
 </Project>

src/Microsoft.AspNetCore.Razor.Language/src/RazorDiagnostic.cs

@@ -1,19 +1,25 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
+using MessagePack;
 
 namespace Microsoft.AspNetCore.Razor.Language;
 
+[MessagePackObject]
+[Union(0, typeof(DefaultRazorDiagnostic))]
 public abstract class RazorDiagnostic : IEquatable<RazorDiagnostic>, IFormattable
 {
     internal static readonly RazorDiagnostic[] EmptyArray = Array.Empty<RazorDiagnostic>();
     internal static readonly object[] EmptyArgs = Array.Empty<object>();
 
+    [Key(0)]
     public abstract string Id { get; }
 
+    [Key(1)]
     public abstract RazorDiagnosticSeverity Severity { get; }
 
+    [Key(2)]
     public abstract SourceSpan Span { get; }
 
     public abstract string GetMessage(IFormatProvider formatProvider);

src/Microsoft.AspNetCore.Razor.Language/src/RequiredAttributeDescriptor.cs

@@ -1,30 +1,42 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using MessagePack;
 
 namespace Microsoft.AspNetCore.Razor.Language;
 
+[MessagePackObject]
+[Union(0, typeof(DefaultRequiredAttributeDescriptor))]
 public abstract class RequiredAttributeDescriptor : IEquatable<RequiredAttributeDescriptor>
 {
+    [Key(0)]
     public string Name { get; protected set; }
 
+    [Key(1)]
     public NameComparisonMode NameComparison { get; protected set; }
 
+    [Key(2)]
     public bool CaseSensitive { get; protected set; }
 
+    [Key(3)]
     public string Value { get; protected set; }
 
+    [Key(4)]
     public ValueComparisonMode ValueComparison { get; protected set; }
 
+    [Key(5)]
     public string DisplayName { get; protected set; }
 
-    public IReadOnlyList<RazorDiagnostic> Diagnostics { get; protected set; }
-
+    [Key(6)]
     public IReadOnlyDictionary<string, string> Metadata { get; protected set; }
 
+    [Key(7)]
+    public IReadOnlyList<RazorDiagnostic> Diagnostics { get; protected set; }
+
+    [IgnoreMember]
     public bool HasErrors
     {
         get

src/Microsoft.AspNetCore.Razor.Language/src/SourceSpan.cs

@@ -3,10 +3,12 @@
 
 using System;
 using System.Globalization;
+using MessagePack;
 using Microsoft.Extensions.Internal;
 
 namespace Microsoft.AspNetCore.Razor.Language;
 
+[MessagePackObject]
 public struct SourceSpan : IEquatable<SourceSpan>
 {
     public static readonly SourceSpan Undefined = new SourceSpan(SourceLocation.Undefined, 0);
@@ -42,18 +44,25 @@ public struct SourceSpan : IEquatable<SourceSpan>
     {
     }
 
+    [Key(0)]
     public int Length { get; }
 
+    [Key(1)]
     public int AbsoluteIndex { get; }
 
+    [Key(2)]
     public int LineIndex { get; }
 
+    [Key(3)]
     public int CharacterIndex { get; }
 
+    [Key(4)]
     public int LineCount { get; }
 
+    [Key(5)]
     public int EndCharacterIndex { get; }
 
+    [Key(6)]
     public string FilePath { get; }
 
     public bool Equals(SourceSpan other)

src/Microsoft.AspNetCore.Razor.Language/src/TagHelperDescriptor.cs

@@ -4,9 +4,12 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using MessagePack;
 
 namespace Microsoft.AspNetCore.Razor.Language;
 
+[MessagePackObject]
+[Union(0, typeof(DefaultTagHelperDescriptor))]
 public abstract class TagHelperDescriptor : IEquatable<TagHelperDescriptor>
 {
     private IEnumerable<RazorDiagnostic> _allDiagnostics;
@@ -17,30 +20,42 @@ public abstract class TagHelperDescriptor : IEquatable<TagHelperDescriptor>
         Kind = kind;
     }
 
+    [Key(0)]
     public string Kind { get; }
 
+    [Key(1)]
     public string Name { get; protected set; }
 
-    public IReadOnlyList<TagMatchingRuleDescriptor> TagMatchingRules { get; protected set; }
-
+    [Key(2)]
     public string AssemblyName { get; protected set; }
 
-    public IReadOnlyList<BoundAttributeDescriptor> BoundAttributes { get; protected set; }
-
-    public IReadOnlyList<AllowedChildTagDescriptor> AllowedChildTags { get; protected set; }
-
-    public string Documentation { get; protected set; }
-
+    [Key(3)]
     public string DisplayName { get; protected set; }
 
+    [Key(4)]
+    public string Documentation { get; protected set; }
+
+    [Key(5)]
     public string TagOutputHint { get; protected set; }
 
+    [Key(6)]
     public bool CaseSensitive { get; protected set; }
 
-    public IReadOnlyList<RazorDiagnostic> Diagnostics { get; protected set; }
+    [Key(7)]
+    public IReadOnlyList<TagMatchingRuleDescriptor> TagMatchingRules { get; protected set; }
 
+    [Key(8)]
+    public IReadOnlyList<BoundAttributeDescriptor> BoundAttributes { get; protected set; }
+
+    [Key(9)]
+    public IReadOnlyList<AllowedChildTagDescriptor> AllowedChildTags { get; protected set; }
+
+    [Key(10)]
     public IReadOnlyDictionary<string, string> Metadata { get; protected set; }
 
+    [Key(11)]
+    public IReadOnlyList<RazorDiagnostic> Diagnostics { get; protected set; }
+
     // Hoisted / cached metadata
     private int? _hashCode;
     internal bool? IsComponentFullyQualifiedNameMatchCache { get; set; }
@@ -55,6 +70,7 @@ public abstract class TagHelperDescriptor : IEquatable<TagHelperDescriptor>
         }
     }
 
+    [IgnoreMember]
     public bool HasErrors
     {
         get

src/Microsoft.AspNetCore.Razor.Language/src/TagMatchingRuleDescriptor.cs

@@ -4,27 +4,36 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using MessagePack;
 
 namespace Microsoft.AspNetCore.Razor.Language;
 
+[MessagePackObject]
+[Union(0, typeof(DefaultTagMatchingRuleDescriptor))]
 public abstract class TagMatchingRuleDescriptor : IEquatable<TagMatchingRuleDescriptor>
 {
     private int? _hashCode;
     private IEnumerable<RazorDiagnostic> _allDiagnostics;
 
+    [Key(0)]
     public string TagName { get; protected set; }
 
-    public IReadOnlyList<RequiredAttributeDescriptor> Attributes { get; protected set; }
-
+    [Key(1)]
     public string ParentTag { get; protected set; }
 
+    [Key(2)]
     public TagStructure TagStructure { get; protected set; }
 
+    [Key(3)]
     public bool CaseSensitive { get; protected set; }
 
+    [Key(4)]
+    public IReadOnlyList<RequiredAttributeDescriptor> Attributes { get; protected set; }
+
+    [Key(5)]
     public IReadOnlyList<RazorDiagnostic> Diagnostics { get; protected set; }
 
-
+    [IgnoreMember]
     public bool HasErrors
     {
         get

src/Microsoft.AspNetCore.Razor.Language/src/idfogc4o.2vz~

@@ -0,0 +1,39 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Collections.Generic;
+using MessagePack;
+
+namespace Microsoft.AspNetCore.Razor.Language;
+
+public class DefaultTagHelperDescriptor : TagHelperDescriptor
+{
+    [SerializationConstructor]
+    public DefaultTagHelperDescriptor(
+        string kind,
+        string name,
+        string assemblyName,
+        string displayName,
+        string documentation,
+        string tagOutputHint,
+        bool caseSensitive,
+        TagMatchingRuleDescriptor[] tagMatchingRules,
+        BoundAttributeDescriptor[] attributeDescriptors,
+        AllowedChildTagDescriptor[] allowedChildTags,
+        Dictionary<string, string> metadata,
+        RazorDiagnostic[] diagnostics)
+        : base(kind)
+    {
+        Name = name;
+        AssemblyName = assemblyName;
+        DisplayName = displayName;
+        Documentation = documentation;
+        TagOutputHint = tagOutputHint;
+        CaseSensitive = caseSensitive;
+        TagMatchingRules = tagMatchingRules;
+        BoundAttributes = attributeDescriptors;
+        AllowedChildTags = allowedChildTags;
+        Diagnostics = diagnostics;
+        Metadata = metadata;
+    }
+}

src/Microsoft.AspNetCore.Razor.Language/src/vtziwkhc.szu~

@@ -0,0 +1,115 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Globalization;
+using MessagePack;
+using Microsoft.Extensions.Internal;
+
+namespace Microsoft.AspNetCore.Razor.Language;
+
+[MessagePackObject]
+public struct SourceSpan : IEquatable<SourceSpan>
+{
+    public static readonly SourceSpan Undefined = new SourceSpan(SourceLocation.Undefined, 0);
+
+    public SourceSpan(int absoluteIndex, int length)
+        : this(null, absoluteIndex, -1, -1, length)
+    {
+    }
+
+    public SourceSpan(SourceLocation location, int contentLength)
+        : this(location.FilePath, location.AbsoluteIndex, location.LineIndex, location.CharacterIndex, contentLength, lineCount: 1, endCharacterIndex: 0)
+    {
+    }
+
+    public SourceSpan(string filePath, int absoluteIndex, int lineIndex, int characterIndex, int length)
+        : this(filePath: filePath, absoluteIndex: absoluteIndex, lineIndex: lineIndex, characterIndex: characterIndex, length: length, lineCount: 0, endCharacterIndex: 0)
+    {
+    }
+
+    public SourceSpan(string filePath, int absoluteIndex, int lineIndex, int characterIndex, int length, int lineCount, int endCharacterIndex)
+    {
+        AbsoluteIndex = absoluteIndex;
+        LineIndex = lineIndex;
+        CharacterIndex = characterIndex;
+        Length = length;
+        FilePath = filePath;
+        LineCount = lineCount;
+        EndCharacterIndex = endCharacterIndex;
+    }
+
+    public SourceSpan(int absoluteIndex, int lineIndex, int characterIndex, int length)
+        : this(filePath: null, absoluteIndex: absoluteIndex, lineIndex: lineIndex, characterIndex: characterIndex, length: length)
+    {
+    }
+
+    [Key(0)]
+    public int Length { get; }
+
+    [Key(1)]
+    public int AbsoluteIndex { get; }
+
+    [Key(2)]
+    public int LineIndex { get; }
+
+    [Key(3)]
+    public int CharacterIndex { get; }
+
+    [Key(4)]
+    public int LineCount { get; }
+
+    [Key(5)]
+    public int EndCharacterIndex { get; }
+
+    [Key(6)]
+    public string FilePath { get; }
+
+    public bool Equals(SourceSpan other)
+    {
+        return
+            string.Equals(FilePath, other.FilePath, StringComparison.Ordinal) &&
+            AbsoluteIndex == other.AbsoluteIndex &&
+            LineIndex == other.LineIndex &&
+            CharacterIndex == other.CharacterIndex &&
+            Length == other.Length;
+    }
+
+    public override bool Equals(object obj)
+    {
+        return obj is SourceSpan span && Equals(span);
+    }
+
+    public override int GetHashCode()
+    {
+        var hash = HashCodeCombiner.Start();
+        hash.Add(FilePath, StringComparer.Ordinal);
+        hash.Add(AbsoluteIndex);
+        hash.Add(LineIndex);
+        hash.Add(CharacterIndex);
+        hash.Add(Length);
+
+        return hash;
+    }
+
+    public override string ToString()
+    {
+        return string.Format(
+            CultureInfo.CurrentCulture, "({0}:{1},{2} [{3}] {4})",
+            AbsoluteIndex,
+            LineIndex,
+            CharacterIndex,
+            Length,
+            FilePath);
+    }
+
+    public static bool operator ==(SourceSpan left, SourceSpan right)
+    {
+        return left.Equals(right);
+    }
+
+    public static bool operator !=(SourceSpan left, SourceSpan right)
+    {
+        return !left.Equals(right);
+    }
+}