Adrian Hey wrote:
Just repeating this again and again doesn't make it any more true.
Ditto... I for one think the best solution is to use the language as intended and pass the values as function arguments. As pointed out on this list - the only possible situation where you cannot do this is when interfacing to a badly written C library. In which case do your one-shot initialisation in C, as you will be importing foreign functions anyway.
Neither
you or any of the other nay-sayers have provided any evidence or credible
justification for this assertion, nor have any of you provided any workable
alternative for even the simplest example. Lennart has yet to explain how he
proposes to implement his supposedly safer "openDevice". You have yet to
explain how you propose to deal with stdout etc..
openDevice would use OS semaphores (like the namedSem library I posted to the cafe) - the OS is the only thing that can deal with device driver initialisations. Infact the OS driver should multiplex single access devices such that access is serialised. I guess stdin, stdout etc should be passed to main as arguments like you would any other file handle. Although if file handles are simply Ints, then there is nothing wrong with having:
stdin = 0 stdout = 1 stderr = 2
In this case they are not IO actions anyway.
And of course there's one top level TWI that none of us can live
without. I am refering to the unique and stateful "world" that is
implicitly referenced by all IO operations (with the possible
exception of those operations I would like to put in the "SafeIO"
monad). So is this evil too? Perhaps it is, but if so, I'd like to
know how you propose to live without it and what purpose the IO monad
would serve in such a situation.
This is true - but only because unsafePerformIO exists. Without it World is simply a value passed via the IO Monad.
I would ask an alternative question - is it possible to live without unsafePerformIO? I have never needed to use it!
Keean _______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
