Type name parsing

ref-asm.cs

public sealed class PublicKeyToken : IEquatable<PublicKeyToken>
{
    public PublicKeyToken(byte[] publicKeyTokenBytes);
    public PublicKeyToken(ReadOnlySpan<byte> publicKeyTokenBytes);
    public PublicKeyToken(string publicKeyTokenHexString);
    public PublicKeyToken(ReadOnlySpan<char> publicKeyTokenHexString);

    public ReadOnlySpan<byte> RawBytes { get; }
    public string TokenString { get; }
    public byte[] GetPublicKeyTokenBytes();

    public override int GetHashCode();
    public override bool Equals(object? other);
    public override bool Equals(PublicKeyToken? other);

    public static bool operator==(PublicKeyToken? other);
}

// https://github.com/dotnet/arcade/blob/e7ede87875f41a9b3df898ae08da5ebc96e24f56/src/Microsoft.DotNet.Arcade.Sdk/tools/StrongName.targets#L23-L76
public static class WellKnownPublicKeyTokens
{
    // b03f5f7f11d50a3a, frequently used by MSFT OSS projects
    public static PublicKeyToken Microsoft { get; }

    // 31BF3856AD364E35, used by netfx 3.0 and later
    public static PublicKeyToken MicrosoftShared { get; }

    // adb9793829ddae60, used by asp.net core
    public static PublicKeyToken MicrosoftAspNetCore { get; }

    // b77a5c561934e089, used by mscorlib and similar
    public static PublicKeyToken ECMA { get; }

    // 7cec85d7bea7798e, used by System.Private.CoreLib
    public static PublicKeyToken SilverlightPlatform { get; }
}

public sealed class AssemblyId : IEquatable<AssemblyId>
{
    public AssemblyId(string assemblyString);
    public AssemblyId(ReadOnlySpan<char> assemblyString);
    public AssemblyId(Assembly assembly);
    public AssemblyId(AssemblyName assemblyName);

    public string Name { get; }
    public Version? Version { get; }
    public string? Culture { get; } // This should be "neutral" by default, perhaps?
    public PublicKeyToken? PublicKeyToken { get; }

    public override int GetHashCode();
    public override bool Equals(object? other);
    public override bool Equals(AssemblyId? other);

    public static bool operator==(AssemblyId? other);

    public AssemblyName ToAssemblyName(); // is it too dangerous to add this?
}

// Builder pattern?

public sealed class AssemblyIdBuilder
{
    public AssemblyIdBuilder();
    public AssemblyIdBuilder(string assemblyString);
    public AssemblyIdBuilder(ReadOnlySpan<char> assemblyString);
    public AssemblyIdBuilder(Assembly assembly);
    public AssemblyIdBuilder(AssemblyName assemblyName);
    public AssemblyIdBuilder(AssemblyId assemblyId);

    public string Name { get; set; } // nullable considerations?
    public Version? Version { get; set; }
    public string? Culture { get; set; } // nullable considerations?
    public PublicKeyToken? PublicKeyToken { get; set; }

    public AssemblyId Build();
}

public sealed class TypeId : IEquatable<TypeId>
{
    public TypeId(string fullTypeName);
    public TypeId(string fullTypeName, string assemblyName);
    public TypeId(ReadOnlySpan<char> fullTypeName);
    public TypeId(ReadOnlySpan<char> fullTypeName, ReadOnlySpan<char> assemblyName);
    public TypeId(Type type);

    public string Name { get; }
    public bool IsGenericType { get; }
    public bool IsGenericTypeDefinition { get; }
    public int GenericParameterCount { get; }
    public TypeId[] GetGenericParameters();
    public AssemblyId? AssemblyId { get; }

    public override int GetHashCode();
    public override bool Equals(object? other);
    public override bool Equals(TypeId? other);

    public static bool operator==(TypeId? other);

    // Do we need transforms?
    // That is, every time you see <x> assembly, replace it with <y> instead?

    public static TypeId ReplaceAssemblyIds(TypeId inputGraph, AssemblyId? searchFor, AssemblyId? replaceWith);
    public static TypeId ReplaceAssemblyIds(TypeId inputGraph, Func<AssemblyId?, AssemblyId?> transformFunction);
}