MarkdownElementSingleChild.cs

using System.Collections.Generic;
using System.Threading.Tasks;
using Waher.Content.Markdown.Model.BlockElements;
 
namespace Waher.Content.Markdown.Model
{
    public abstract class MarkdownElementSingleChild : MarkdownElement
    {
        private MarkdownElement child;
 
        public MarkdownElementSingleChild(MarkdownDocument Document, MarkdownElement Child)
            : base(Document)
        {
            if (Child is NestedBlock NestedBlock && NestedBlock.HasOneChild)
                this.child = NestedBlock.FirstChild;
            else
                this.child = Child;
        }
 
        public MarkdownElement Child
        {
            get => this.child;
            internal set => this.child = value;
        }
 
        public override IEnumerable<MarkdownElement> Children => new MarkdownElement[] { this.child };
 
        public abstract MarkdownElementSingleChild Create(MarkdownElement Child, MarkdownDocument Document);
 
        public override bool ForEach(MarkdownElementHandler Callback, object State)
        {
            if (!Callback(this, State))
                return false;
 
            if (!(this.child is null) && !this.child.ForEach(Callback, State))
                return false;
 
            return true;
        }
 
        public override bool Equals(object obj)
        {
            return obj is MarkdownElementSingleChild x &&
                (this.child?.Equals(x.child) ?? x.child is null) &&
                base.Equals(obj);
        }
 
        public override int GetHashCode()
        {
            int h1 = base.GetHashCode();
            int h2 = this.child?.GetHashCode() ?? 0;
 
            h1 = ((h1 << 5) + h1) ^ h2;
 
            return h1;
        }
 
    }
}