IEntryVisitor

IEntryVisitable is interface for visitable entries.

/// <summary>Visitable entry.</summary>
public interface IEntryVisitable : IEntry
{
    /// <summary>Try accept <paramref name="visitor"/>.</summary>
    /// <param name="visitor"></param>
    /// <param name="response"></param>
    /// <returns>True if was visited</returns>
    bool Accept<Visitor, Arg>(Visitor visitor, ref Arg response) where Visitor : IEntryVisitor<Arg>;
}

IEntryVisitor is interface for visitors.

/// <summary>Indicates that is entry visitor</summary>
public interface IEntryVisitor { }
/// <summary>Indicates that is entry visitor</summary>
public interface IEntryVisitorT : IEntryVisitor { }
/// <summary>Indicates that is entry visitor</summary>
public interface IEntryVisitor<Arg> : IEntryVisitorT { }

/// <summary>Indicates that is entry visitor</summary>
public interface IEntryReadableVisitorT : IEntryVisitorT { }
/// <summary>Interface for visitor implementations. Upon visitation the visited entry is casted to the entry value.</summary>
/// <typeparam name="Arg"></typeparam>
public interface IEntryReadableVisitor<Arg> : IEntryReadableVisitorT, IEntryVisitor<Arg>
{
    /// <summary>Visit <see cref="IEntryReadable{Value}"/>.</summary>
    /// <returns>Should visitation continue</returns>
    bool Visit<Value>(IEntryReadable<Value> readableEntry, ref Arg response);
}

/// <summary>Indicates that is entry visitor</summary>
public interface IEntryWritableVisitorT : IEntryVisitor { }
/// <summary>Interface for visitor implementations. Upon visitation the visited entry is casted to the entry value.</summary>
/// <typeparam name="Arg"></typeparam>
public interface IEntryWritableVisitor<Arg> : IEntryWritableVisitorT, IEntryVisitor<Arg>
{
    /// <summary>Visit <see cref="IEntryWritable{Value}"/>.</summary>
    /// <returns>Should visitation continue</returns>
    bool Visit<Value>(IEntryWritable<Value> writableEntry, ref Arg response);
}

.Accept() takes visitor and one argument with ref pointer.

// Create entry
IEntryVisitable entry = (IEntryVisitable)new Entry<string>();
// Create visitor
IEntryVisitor<object?> visitor = new Visitor();
// Visit
object? arg = null;
entry.Accept(visitor, ref arg);

class Visitor : IEntryReadableVisitor<object?>
{
    public bool Visit<Value>(IEntryReadable<Value> readableEntry, ref object? response)
    {
        Console.WriteLine(typeof(Value).FullName);
        return true;
    }
}

Full Example

Full example

using System;
using Avalanche.Service;

public class entry_visitable
{
    public static void Run()
    {
        {
            // <01>
            // Create entry
            IEntryVisitable entry = (IEntryVisitable)new Entry<string>();
            // Create visitor
            IEntryVisitor<object?> visitor = new Visitor();
            // Visit
            object? arg = null;
            entry.Accept(visitor, ref arg);
            // </01>
        }
    }

    // <99>
    class Visitor : IEntryReadableVisitor<object?>
    {
        public bool Visit<Value>(IEntryReadable<Value> readableEntry, ref object? response)
        {
            Console.WriteLine(typeof(Value).FullName);
            return true;
        }
    }
    // </99>
}