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// Copyright 2024 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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//go:build go1.23
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package html
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import "iter"
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// Ancestors returns an iterator over the ancestors of n, starting with n.Parent.
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//
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// Mutating a Node or its parents while iterating may have unexpected results.
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func (n *Node) Ancestors() iter.Seq[*Node] {
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	_ = n.Parent // eager nil check
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	return func(yield func(*Node) bool) {
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		for p := n.Parent; p != nil && yield(p); p = p.Parent {
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		}
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	}
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}
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// ChildNodes returns an iterator over the immediate children of n,
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// starting with n.FirstChild.
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//
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// Mutating a Node or its children while iterating may have unexpected results.
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func (n *Node) ChildNodes() iter.Seq[*Node] {
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	_ = n.FirstChild // eager nil check
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	return func(yield func(*Node) bool) {
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		for c := n.FirstChild; c != nil && yield(c); c = c.NextSibling {
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		}
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	}
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}
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// Descendants returns an iterator over all nodes recursively beneath
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// n, excluding n itself. Nodes are visited in depth-first preorder.
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//
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// Mutating a Node or its descendants while iterating may have unexpected results.
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func (n *Node) Descendants() iter.Seq[*Node] {
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	_ = n.FirstChild // eager nil check
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	return func(yield func(*Node) bool) {
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		n.descendants(yield)
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	}
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}
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func (n *Node) descendants(yield func(*Node) bool) bool {
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	for c := range n.ChildNodes() {
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		if !yield(c) || !c.descendants(yield) {
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			return false
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		}
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	}
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	return true
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}
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