rss-tools @ master

// Copyright 2024 The Go Authors. All rights reserved.

// Use of this source code is governed by a BSD-style

// license that can be found in the LICENSE file.

package html

import "iter"

// Ancestors returns an iterator over the ancestors of n, starting with n.Parent.

//

// Mutating a Node or its parents while iterating may have unexpected results.

func (n *Node) Ancestors() iter.Seq[*Node] {

	_ = n.Parent // eager nil check

	return func(yield func(*Node) bool) {

		for p := n.Parent; p != nil && yield(p); p = p.Parent {

		}

	}

}

// ChildNodes returns an iterator over the immediate children of n,

// starting with n.FirstChild.

//

// Mutating a Node or its children while iterating may have unexpected results.

func (n *Node) ChildNodes() iter.Seq[*Node] {

	_ = n.FirstChild // eager nil check

	return func(yield func(*Node) bool) {

		for c := n.FirstChild; c != nil && yield(c); c = c.NextSibling {

		}

	}

}

// Descendants returns an iterator over all nodes recursively beneath

// n, excluding n itself. Nodes are visited in depth-first preorder.

//

// Mutating a Node or its descendants while iterating may have unexpected results.

func (n *Node) Descendants() iter.Seq[*Node] {

	_ = n.FirstChild // eager nil check

	return func(yield func(*Node) bool) {

		n.descendants(yield)

	}

}

func (n *Node) descendants(yield func(*Node) bool) bool {

	for c := range n.ChildNodes() {

		if !yield(c) || !c.descendants(yield) {

			return false

		}

	}

	return true

}