On 11 April 2006 13:35, John Meacham wrote: > On Tue, Apr 11, 2006 at 01:24:07PM +0100, Simon Marlow wrote: >> Attached is another variant of the extensible exceptions idea, it >> improves on the previous designs in a couple of ways: there's only >> one catch & throw, regardless of what type you're throwing or >> catching. There is an extensible hierarchy of exceptions, and you >> can catch and re-throw subclasses of exceptions. > > I made the catch and throw separate so the decision as to whether to > include imprecice exceptions and extensible extensions can be made > independently. > > that and > > throw x /= ioError x > > ioError x >> return () -> IO _|_ (only _|_ when IO action executed) > throw x >> return () -> _|_ > > ioError x `seq` () -> () > throw x `seq` () -> _|_
yes, when I say "one throw" I was referring to the argument type, not the return type. We should still have ioError - although it would probably be better named throwIO: http://www.haskell.org/ghc/docs/latest/html/libraries/base/Control-Excep tion.html#v%3AthrowIO (the docs for throwIO also mention the strictness property you described above) Cheers, Simon _______________________________________________ Haskell-prime mailing list Haskell-prime@haskell.org http://haskell.org/mailman/listinfo/haskell-prime