SexpGenerator = object
  s: string
  files: Table[string, int]

proc addLineInfo(gen: var SexpGenerator; info: LineInfo) {....raises: [], tags: [].}

proc addUntypedNode(gen: var SexpGenerator; node: UntypedNode) {....raises: [],
    tags: [].}

proc filesToSexp(filesTable: Table[string, int]): string {....raises: [], tags: [].}

proc toSexp(nodes: seq[UntypedNode]): string {....raises: [], tags: [].}