IdentityComparer

IdentityComparer implements IEqualityComparer<IIdentity>.

IEqualityComparer<IIdentity> equalityComparer = IdentityComparer.Default;

It compares following properties: Part, Parent, Components, Label. Uses label accessor comparer if available.

string typename = typeof(string).AssemblyQualifiedName;
// Parse
IIdentity id2 = IdentityAccessors.Default.TypeName.MemoryAccessors.Parse(typename.AsMemory());
// Create
IIdentity id1 = IdentityAccessors.Default.TypeName.Create(typeof(string));
// 'True'
WriteLine(equalityComparer.Equals(id1, id2));

Two equal identities produce same hashcode.

// '495866146'
WriteLine(equalityComparer.GetHashCode(id1));
// '495866146'
WriteLine(equalityComparer.GetHashCode(id2));

IdentityComparer implements also IComparer<IIdentity>.

// Order comparer
IComparer<IIdentity> comparer = IdentityComparer.Default;
// Array of identities
IIdentity[] array = new[]
{
    Identities.CreateNamespace("System").AppendName("String"),
    Identities.CreateNamespace("System").AppendName("Int"),
    Identities.CreateNamespace("System"),
    Identities.CreateNamespace("Avalanche").AppendNamespace("Identity").AppendName("IIdentity<T>"),
    Identities.CreateNamespace("Avalanche").AppendNamespace("Identity").AppendName("Identity<T>"),
    Identities.CreateNamespace("Avalanche").AppendNamespace("Service").AppendName("IService"),
    Identities.CreateNamespace("Avalanche"),
};
// Sort array
Array.Sort(array, comparer);
// Print array
foreach (IIdentity id in array)
    WriteLine(IdentityAccessors.Default.TypeName.MemoryAccessors.Printing.Print(id));

Avalanche
Avalanche.Identity.Identity
Avalanche.Identity.IIdentity
Avalanche.Service.IService
System
System.Int
System.String

Case Insensitive

IdentityComparer.CaseInsensitive overrides label accessor string comparers with StringComparer.OrdinalIgnoreCase.

// Order comparer
IdentityComparer comparer = IdentityComparer.CaseInsensitive;
//
IIdentity id1 = Identities.CreateNamespace("sYsTeM").AppendName("StRiNg");
IIdentity id2 = Identities.CreateNamespace("SYSTEM").AppendName("string");
// '-1907792046'
WriteLine(comparer.GetHashCode(id1));
WriteLine(comparer.GetHashCode(id2));
// 'True'
WriteLine(comparer.Equals(id1, id2));
// 'False'
WriteLine(id1.Equals(id2));

CaseInsensitive comparer also sorts insensitive.

// Order comparer
IComparer<IIdentity> comparer = IdentityComparer.CaseInsensitive;
// Array of identities
IIdentity[] array = new[]
{
    Identities.CreateNamespace("system").AppendName("String"),
    Identities.CreateNamespace("SysTem").AppendName("Int"),
    Identities.CreateNamespace("system"),
    Identities.CreateNamespace("AvalaNche").AppendNamespace("Identity").AppendName("IIdentity<T>"),
    Identities.CreateNamespace("avalancHe").AppendNamespace("Identity").AppendName("Identity<T>"),
    Identities.CreateNamespace("AvalanchE").AppendNamespace("Service").AppendName("IService"),
    Identities.CreateNamespace("Avalanche"),
};
// Sort array
Array.Sort(array, comparer);
// Print array
foreach (IIdentity id in array)
    WriteLine(IdentityAccessors.Default.TypeName.MemoryAccessors.Print(id));

Avalanche
avalancHe.Identity.Identity
AvalaNche.Identity.IIdentity
AvalanchE.Service.IService
system
SysTem.Int
system.String

Other Special Cases

Comparer can be constructed with argument 'partsToDisregard:' that lists parts that are not to be compared.

// "System.String, Library, Version=1.2.3, Culture=neutral, PublicKeyToken=0102030405060708"
IIdentity typeid1 =
    IdentityBase
    .Create<byte[]>(new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 }, IdentityParts.PublicKeyToken, "Hex")
    .Append<string>("neutral", IdentityParts.Culture, LabelAccessors.Default.String)
    .Append<string>("Library", IdentityParts.Library, LabelAccessors.Default.String)
    .Append<string>("1.2.3", IdentityParts.Version, LabelAccessors.Default.String)
    .AppendNamespace("System")
    .AppendName("String");
// "System.String, Library, Version=2.3.4, Culture=en, PublicKeyToken=0807060504030201"
IIdentity typeid2 =
    IdentityBase.Create<byte[]>(new byte[] { 8, 7, 6, 5, 4, 3, 2, 1 }, IdentityParts.PublicKeyToken, "Hex")
    .Append<string>("en", IdentityParts.Culture, LabelAccessors.Default.String)
    .Append<string>("Library", IdentityParts.Library, LabelAccessors.Default.String)
    .Append<string>("2.3.4", IdentityParts.Version, LabelAccessors.Default.String)
    .AppendNamespace("System")
    .AppendName("String");
// Compare with regular comparer: "False"
WriteLine(IdentityComparer.Default.Equals(typeid1, typeid2));
// Create comparer that ignores: none, version, culture, and token
IdentityComparer comparer = new IdentityComparer(partsToDisregard: new HashSet<Label8> { "", "Version", "Culture", "PuKeyTkn" });
// Compare now: "True"
WriteLine(comparer.Equals(typeid1, typeid2));

Comparer can also be constructed with argument 'partsToRegard:' that is a list of parts only to compare.

// Create comparer that compares only: name, namespace, library
IdentityComparer comparer2 = new IdentityComparer(partsToRegard: new HashSet<Label8> { "Name", "Namespce", "Library" });
// Compare now: "True"
WriteLine(comparer2.Equals(typeid1, typeid2));

Full Example

Full example

using System;
using System.Collections.Generic;
using Avalanche.Accessor;
using Avalanche.Identity;
using Avalanche.Serialization;
using Avalanche.Utilities;
using static System.Console;

class identitycomparer
{
    public static void Run()
    {
        {
            // <01>
            IEqualityComparer<IIdentity> equalityComparer = IdentityComparer.Default;
            // </01>

            // <02>
            string typename = typeof(string).AssemblyQualifiedName;
            // Parse
            IIdentity id2 = IdentityAccessors.Default.TypeName.MemoryAccessors.Parse(typename.AsMemory());
            // Create
            IIdentity id1 = IdentityAccessors.Default.TypeName.Create(typeof(string));
            // 'True'
            WriteLine(equalityComparer.Equals(id1, id2));
            // </02>

            // <03>
            // '495866146'
            WriteLine(equalityComparer.GetHashCode(id1));
            // '495866146'
            WriteLine(equalityComparer.GetHashCode(id2));
            // </03>
        }
        {
            // <11>
            // Order comparer
            IComparer<IIdentity> comparer = IdentityComparer.Default;
            // Array of identities
            IIdentity[] array = new[]
            {
                Identities.CreateNamespace("System").AppendName("String"),
                Identities.CreateNamespace("System").AppendName("Int"),
                Identities.CreateNamespace("System"),
                Identities.CreateNamespace("Avalanche").AppendNamespace("Identity").AppendName("IIdentity<T>"),
                Identities.CreateNamespace("Avalanche").AppendNamespace("Identity").AppendName("Identity<T>"),
                Identities.CreateNamespace("Avalanche").AppendNamespace("Service").AppendName("IService"),
                Identities.CreateNamespace("Avalanche"),
            };
            // Sort array
            Array.Sort(array, comparer);
            // Print array
            foreach (IIdentity id in array)
                WriteLine(IdentityAccessors.Default.TypeName.MemoryAccessors.Printing.Print(id));
            // </11>
        }
        WriteLine();
        {
            // <12>
            // Order comparer
            IdentityComparer comparer = IdentityComparer.CaseInsensitive;
            //
            IIdentity id1 = Identities.CreateNamespace("sYsTeM").AppendName("StRiNg");
            IIdentity id2 = Identities.CreateNamespace("SYSTEM").AppendName("string");
            // '-1907792046'
            WriteLine(comparer.GetHashCode(id1));
            WriteLine(comparer.GetHashCode(id2));
            // 'True'
            WriteLine(comparer.Equals(id1, id2));
            // 'False'
            WriteLine(id1.Equals(id2));
            // </12>
        }
        WriteLine();
        {
            // <13>
            // Order comparer
            IComparer<IIdentity> comparer = IdentityComparer.CaseInsensitive;
            // Array of identities
            IIdentity[] array = new[]
            {
                Identities.CreateNamespace("system").AppendName("String"),
                Identities.CreateNamespace("SysTem").AppendName("Int"),
                Identities.CreateNamespace("system"),
                Identities.CreateNamespace("AvalaNche").AppendNamespace("Identity").AppendName("IIdentity<T>"),
                Identities.CreateNamespace("avalancHe").AppendNamespace("Identity").AppendName("Identity<T>"),
                Identities.CreateNamespace("AvalanchE").AppendNamespace("Service").AppendName("IService"),
                Identities.CreateNamespace("Avalanche"),
            };
            // Sort array
            Array.Sort(array, comparer);
            // Print array
            foreach (IIdentity id in array)
                WriteLine(IdentityAccessors.Default.TypeName.MemoryAccessors.Print(id));
            // </13>
        }

        {
            // Create
            // <20>
            // "System.String, Library, Version=1.2.3, Culture=neutral, PublicKeyToken=0102030405060708"
            IIdentity typeid1 =
                IdentityBase
                .Create<byte[]>(new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 }, IdentityParts.PublicKeyToken, "Hex")
                .Append<string>("neutral", IdentityParts.Culture, LabelAccessors.Default.String)
                .Append<string>("Library", IdentityParts.Library, LabelAccessors.Default.String)
                .Append<string>("1.2.3", IdentityParts.Version, LabelAccessors.Default.String)
                .AppendNamespace("System")
                .AppendName("String");
            // "System.String, Library, Version=2.3.4, Culture=en, PublicKeyToken=0807060504030201"
            IIdentity typeid2 =
                IdentityBase.Create<byte[]>(new byte[] { 8, 7, 6, 5, 4, 3, 2, 1 }, IdentityParts.PublicKeyToken, "Hex")
                .Append<string>("en", IdentityParts.Culture, LabelAccessors.Default.String)
                .Append<string>("Library", IdentityParts.Library, LabelAccessors.Default.String)
                .Append<string>("2.3.4", IdentityParts.Version, LabelAccessors.Default.String)
                .AppendNamespace("System")
                .AppendName("String");
            // Compare with regular comparer: "False"
            WriteLine(IdentityComparer.Default.Equals(typeid1, typeid2));
            // Create comparer that ignores: none, version, culture, and token
            IdentityComparer comparer = new IdentityComparer(partsToDisregard: new HashSet<Label8> { "", "Version", "Culture", "PuKeyTkn" });
            // Compare now: "True"
            WriteLine(comparer.Equals(typeid1, typeid2));
            // </20>            
            // <21>
            // Create comparer that compares only: name, namespace, library
            IdentityComparer comparer2 = new IdentityComparer(partsToRegard: new HashSet<Label8> { "Name", "Namespce", "Library" });
            // Compare now: "True"
            WriteLine(comparer2.Equals(typeid1, typeid2));
            // </21>
        }

    }
}