Procs

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

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

proc unpack_from(format, buffer: string; offset = 0) {.
    ...raises: [Exception, ValueError, OSError, IOError, EOFError, KeyError],
    tags: [RootEffect].}