private static IEnumerable <T> BlockDescendantsInternal <T>(ContainerBlock block) where T : MarkdownObject
{
Debug.Assert(typeof(T).IsSubclassOf(typeof(Block)));
Stack <Block> stack = new Stack <Block>();
int childrenCount = block.Count;
while (childrenCount-- > 0)
{
stack.Push(block[childrenCount]);
}
while (stack.Count > 0)
{
var subBlock = stack.Pop();
if (subBlock is T subBlockT)
{
yield return(subBlockT);
}
if (subBlock is ContainerBlock subBlockContainer)
{
childrenCount = subBlockContainer.Count;
while (childrenCount-- > 0)
{
stack.Push(subBlockContainer[childrenCount]);
}
}
}
}
/// <summary>
/// Iterates over the descendant elements for the specified markdown <see cref="Block" /> element and filters by the type {T}.
/// </summary>
/// <typeparam name="T">Type to use for filtering the descendants</typeparam>
/// <param name="block">The markdown object.</param>
/// <returns>
/// An iteration over the descendant elements
/// </returns>
public static IEnumerable <T> Descendants <T>(this ContainerBlock block) where T : Block
{
// Fast-path an empty container to avoid allocating a Stack
if (block.Count == 0)
{
yield break;
}
Stack <Block> stack = new Stack <Block>();
int childrenCount = block.Count;
while (childrenCount-- > 0)
{
stack.Push(block[childrenCount]);
}
while (stack.Count > 0)
{
var subBlock = stack.Pop();
if (subBlock is T subBlockT)
{
yield return(subBlockT);
}
if (subBlock is ContainerBlock subBlockContainer)
{
childrenCount = subBlockContainer.Count;
while (childrenCount-- > 0)
{
stack.Push(subBlockContainer[childrenCount]);
}
}
}
}
/// <summary>
/// Iterates over the descendant elements for the specified markdown <see cref="Block" /> element and filters by the type <typeparamref name="T"/>.
/// </summary>
/// <typeparam name="T">Type to use for filtering the descendants</typeparam>
/// <param name="block">The markdown object.</param>
/// <returns>
/// An iteration over the descendant elements
/// </returns>
public static IEnumerable <T> Descendants <T>(this ContainerBlock block) where T : Block
{
if (block != null && block.Count > 0)
{
return(BlockDescendantsInternal <T>(block));
}
else
{
return(ArrayHelper <T> .Empty);
}
}
private static IEnumerable <T> InlineDescendantsInternal <T>(ContainerBlock block) where T : MarkdownObject
{
Debug.Assert(typeof(T).IsSubclassOf(typeof(Inline)));
foreach (MarkdownObject descendant in block.Descendants())
{
if (descendant is T descendantT)
{
yield return(descendantT);
}
}
}
/// <summary>
/// Iterates over the descendant elements for the specified markdown <see cref="Block" /> element and filters by the type {T}.
/// </summary>
/// <typeparam name="T">Type to use for filtering the descendants</typeparam>
/// <param name="block">The markdown object.</param>
/// <returns>
/// An iteration over the descendant elements
/// </returns>
public static IEnumerable <T> Descendants <T>(this ContainerBlock block) where T : Block
{
foreach (var subBlock in block)
{
var subBlockT = subBlock as T;
if (subBlockT != null)
{
yield return(subBlockT);
}
var subBlockContainer = subBlock as ContainerBlock;
if (subBlockContainer != null)
{
foreach (var sub in subBlockContainer.Descendants <T>())
{
yield return(sub);
}
}
}
}
internal Enumerator(ContainerBlock block)
{
this.block = block;
index = 0;
current = null;
}
/// <summary>
/// Iterates over the descendant elements for the specified markdown <see cref="Block" /> element and filters by the type <typeparamref name="T"/>.
/// </summary>
/// <typeparam name="T">Type to use for filtering the descendants</typeparam>
/// <param name="block">The markdown object.</param>
/// <returns>
/// An iteration over the descendant elements
/// </returns>
public static IEnumerable <T> Descendants <T>(this ContainerBlock block) where T : Block
{
if (block is { Count : > 0 })
