extensions/emmet/src/matchTag.ts/matchTag
export function matchTag() {
	if (!validate(false) || !vscode.window.activeTextEditor) {
		return;
	}

	const editor = vscode.window.activeTextEditor;
	const document = editor.document;
	const rootNode = <HtmlFlatNode>getRootNode(document, true);
	if (!rootNode) {
		return;
	}

	let updatedSelections: vscode.Selection[] = [];
	editor.selections.forEach(selection => {
		const updatedSelection = getUpdatedSelections(document, rootNode, selection.start);
		if (updatedSelection) {
			updatedSelections.push(updatedSelection);
		}
	});
	if (updatedSelections.length) {
		editor.selections = updatedSelections;
		editor.revealRange(editor.selections[updatedSelections.length - 1]);
	}
}