Method addFormattingElement

html/parse.go:347–387

Section 12.2.4.3.

()

// Section 12.2.4.3.
func (p *parser) addFormattingElement() {
	tagAtom, attr := p.tok.DataAtom, p.tok.Attr
	p.addElement()

	// In order to optimize the search, we need the attributes to be sorted, so we
	// can just use slices.Equal.
	slices.SortFunc(attr, attrCompare)

	// Implement the Noah's Ark clause, but with three per family instead of two.
	identicalElements := 0
findIdenticalElements:
	for i := len(p.afe) - 1; i >= 0; i-- {
		n := p.afe[i]
		if n.Type == scopeMarkerNode {
			break
		}
		if n.Type != ElementNode {
			continue
		}
		if n.Namespace != "" {
			continue
		}
		if n.DataAtom != tagAtom {
			continue
		}
		if !slices.Equal(n.Attr, attr) {
			continue findIdenticalElements
		}

		identicalElements++
		if identicalElements >= 3 {
			p.afe.remove(n)
		}
	}

	// Sort the attributes to optimize future identical-element searches.
	top := p.top()
	slices.SortFunc(top.Attr, attrCompare)

	p.afe = append(p.afe, top)
}

// Section 12.2.4.3.
func (p *parser) clearActiveFormattingElements() {