-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Adrian Hey wrote:
Furthermore, if it is going to take this state handle as an explicit argument then you need to provide some way for users to get this state handle. This could be by.. 1 - Making it an argument of main. 2 - Exposing a newLibWhateverState constructor 3 - Exposing a getLibWhateverState "getter".
Problems.. 1 Requires the type of main to depend on what IO libs are used. Also the Boot code that invokes main must get this state handle from somewhere. 2 Potentially permits 2 or more libWhateverStates to be created (in which case all bets are off re. the safety proprties I was talking about). 3 Can't be implemented without making use of..you know what.
Making it an argument of main (1) is somewhat the same as doing (3) - consider getArgs. What bothers me is the IO-state in the Haskell standard (arguments, random state...) which is a set not extensible without the hack. (It bothers me that there _are_ so many things in that set, somewhat ad-hoc-ly it seems :)
Unfortunately the situation seems worse than this. AFAICT we haven't even got a consensus that that there is a real problem here that needs any kind of solution :-)
The unsafePerformIO hack being used is not very satisfactory given how many optimizations make it difficult to use safely in practice. This hack is also used many places. I would be happier if that situation were not true, and I suspect there's something like a consensus on _that_. (maybe not as strong as "_needs_ a solution" in the short-to-mid term future) Isaac -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFGTg2+HgcxvIWYTTURAvWfAKC36q24IKTX5YQOVi+A4gNYLzBMMACePwkL dwnAlZh++e2EqiFKvJEmn1M= =NBHG -----END PGP SIGNATURE-----