[Haskell] help -- need a random number

Marc A. Ziegert coeus at gmx.de
Thu Apr 26 15:06:10 EDT 2007


that is exact the way, how i had learned about the state monads like IO and Maybe.
that was even before i understood the [] monad, folding and using Random; i don't remember when that was... ghc-5.xx age.

in my opinion, unsafePerformIO is a good learning tool, as soon as you use it tricky to analyze and discover "new worlds you have never been before".
like this:

blah = unsafePerformIO $ do
	putStrLn "I'm here: blah!"
	return blub

this way, it may be even more important than undefined:

undef s = unsafePerformIO $ do
	putStrLn "whops, this shouldn't happen"
	putStrLn s
	return undefined


well, this is my unpure way of learning to think in new languages.
i used ways like this in c++ to analyze OOP and to discover the world before and after int main().

greetings
- marc

Am Donnerstag, 26. April 2007 20:15 schrieb Johannes Waldmann:
> 
> > import System.IO.Unsafe (unsafePerformIO,unsafeInterleaveIO)
> 
> Whoa! I'd be very cautious recommending these for newbies ...
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