MarkdownElementChildren.cs

using System.Collections.Generic;
using System.Threading.Tasks;
 
namespace Waher.Content.Markdown.Model
{
    public abstract class MarkdownElementChildren : MarkdownElement
    {
        private IEnumerable<MarkdownElement> children;
 
        public MarkdownElementChildren(MarkdownDocument Document, IEnumerable<MarkdownElement> Children)
            : base(Document)
        {
            this.children = Children;
        }
 
        public MarkdownElementChildren(MarkdownDocument Document, params MarkdownElement[] Children)
            : base(Document)
        {
            this.children = Children;
        }
 
        public void AddChildren(params MarkdownElement[] NewChildren)
        {
            this.AddChildren((IEnumerable<MarkdownElement>)NewChildren);
        }
 
        public virtual void AddChildren(IEnumerable<MarkdownElement> NewChildren)
        {
            if (!(this.children is LinkedList<MarkdownElement> Children))
            {
                Children = new LinkedList<MarkdownElement>();
            
                foreach (MarkdownElement E in this.children)
                    Children.AddLast(E);
                
                this.children = Children;
            }
 
            foreach (MarkdownElement E in NewChildren)
                Children.AddLast(E);
        }
 
        public MarkdownElement FirstChild
        {
            get
            {
                foreach (MarkdownElement E in this.children)
                    return E;
 
                return null;
            }
        }
 
        public MarkdownElement LastChild
        {
            get
            {
                MarkdownElement Result = null;
 
                foreach (MarkdownElement E in this.children)
                    Result = E;
 
                return Result;
            }
        }
 
        public bool HasOneChild
        {
            get
            {
                bool First = true;
 
                foreach (MarkdownElement E in this.children)
                {
                    if (First)
                        First = false;
                    else
                        return false;
                }
 
                return !First;
            }
        }
 
        public override IEnumerable<MarkdownElement> Children => this.children;
 
        protected void SetChildren(IEnumerable<MarkdownElement> Children)
        {
            this.children = Children;
        }
 
        public abstract MarkdownElementChildren Create(IEnumerable<MarkdownElement> Children, MarkdownDocument Document);
 
        internal virtual bool JoinOverParagraphs => false;
 
        public override bool ForEach(MarkdownElementHandler Callback, object State)
        {
            if (!Callback(this, State))
                return false;
 
            if (!(this.children is null))
            {
                foreach (MarkdownElement E in this.children)
                {
                    if (!E.ForEach(Callback, State))
                        return false;
                }
            }
 
            return true;
        }
 
        public override bool Equals(object obj)
        {
            if (!(obj is MarkdownElementChildren x) || !base.Equals(obj))
                return false;
 
            IEnumerator<MarkdownElement> e1 = this.children.GetEnumerator();
            IEnumerator<MarkdownElement> e2 = x.children.GetEnumerator();
            bool b1, b2;
 
            while (true)
            {
                b1 = e1.MoveNext();
                b2 = e2.MoveNext();
 
                if (b1 ^ b2)
                    return false;
 
                if (!b1)
                    return true;
 
                if (!e1.Current.Equals(e2.Current))
                    return false;
            }
        }
 
        public override int GetHashCode()
        {
            int h1 = base.GetHashCode();
            int h2;
 
            foreach (MarkdownElement E in this.children)
            {
                h2 = E.GetHashCode();
                h1 = ((h1 << 5) + h1) ^ h2;
            }
 
            return h1;
        }
 
    }
}