Re: [Haskell-cafe] How can i safely change the value of specified key ?

2009/10/22 zaxis :

aaa <- newIORef ([]::[(Int,Int)]) writeIORef aaa [(1,1),(2,2),(3,3)]

then if i want to change aaa to [(1,1),(2,222),(3,3)] , what's the best way ? re-write aaa is not permitted.

Why do you say that ? You can use again writeIORef of modifyIORef to change aaa's content. Cheers, Thu