proc boolArg(conf: ConfigRef; n: PNode; name: string; pos: int; default: bool): bool {.
    ...raises: [Exception], tags: [RootEffect].}

proc charArg(conf: ConfigRef; n: PNode; name: string; pos: int; default: char): char {.
    ...raises: [Exception], tags: [RootEffect].}

proc filterReplace(conf: ConfigRef; stdin: PLLStream; filename: AbsoluteFile;
                   call: PNode): PLLStream {....raises: [Exception, IOError],
    tags: [RootEffect, ReadIOEffect, WriteIOEffect].}

proc filterStrip(conf: ConfigRef; stdin: PLLStream; filename: AbsoluteFile;
                 call: PNode): PLLStream {....raises: [Exception, IOError],
    tags: [RootEffect, ReadIOEffect, WriteIOEffect].}

proc strArg(conf: ConfigRef; n: PNode; name: string; pos: int; default: string): string {.
    ...raises: [Exception], tags: [RootEffect].}