Axel Simon wrote: > > > Does anyone know why these are in the IO monad? Aren't they pure functions > > > converting between dotted-decimal strings and a 32-bit network byte > > > ordered > > > binary value? > > I guess the answer is no for both: The first one can fail
That doesn't mean that it should be in the IO monad; using Maybe would suffice. > and the second one overwrites a fixed string buffer (yuck!). From > the man page: > > The return value from inet_ntoa() points to a buffer which > is overwritten on each call. This buffer is implemented as > thread-specific data in multithreaded applications. > > Hence ntoa needs to be an IO action so that the value is read > immediately before the next ntoa call is executed. That shouldn't be an issue so long as the buffer contents are converted to a Haskell String before the function is called again within the same thread. However, I wouldn't rely upon all implementations of inet_ntoa() being thread-safe. > What you could do is to apply unsafePerformIO to [snip] Or you could just re-implement the functions in Haskell. Apart from the re-entrancy issues with inet_ntoa(), many implementations of inet_addr() have misfeatures, e.g. allowing octets to be expressed in octal or hex, or allowing numbers outside of the 0-255 range (in which case, the top bits overflow into the next octet). -- Glynn Clements <[EMAIL PROTECTED]> _______________________________________________ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
