Procs

proc getline(filename: string; lineno: int): string {.
    ...raises: [Exception, ValueError, OSError, IOError, EOFError, KeyError],
    tags: [RootEffect].}

proc clearcache() {....raises: [Exception, ValueError, OSError, IOError, EOFError,
                             KeyError], tags: [RootEffect].}

proc checkcache(filename: string): string {.
    ...raises: [Exception, ValueError, OSError, IOError, EOFError, KeyError],
    tags: [RootEffect].}

proc lazycache(filename: string): string {.
    ...raises: [Exception, ValueError, OSError, IOError, EOFError, KeyError],
    tags: [RootEffect].}