  filenames: files.FullFilePath[],
  sourceDir: files.SourceDir,
  tagMapper: TagMapper
): Promise<ast.NodeList[]> {
  const result = []
  const parser = new Parser(tagMapper)
  for (const filename of filenames) {
    const content = await fs.readFile(sourceDir.joinFullFile(filename).platformified(), {
      encoding: "utf8",
    })
    result.push(parser.parse(content, new files.Location(sourceDir, filename, 1)))