Could mkWeakPair do what you want? http://haskell.org/ghc/docs/latest/html/libraries/base/System-Mem-Weak.html#v:mkWeakPair
Or are you trying to do something else? - Job 2009/11/2 Patai Gergely <patai_gerg...@fastmail.fm> > Hello all, > > I wanted to create a weak pointer with an IORef as the key and something > else as the value, but I saw no way to do it through the API provided. > After some experimentation I came up with the following abomination for > a solution: > > myWeakRef (IORef (STRef r)) v f = > IO $ \s -> case mkWeak# r v f s of (# s', w #) -> (# s', Weak w #) > > This works perfectly when the code is compiled both with and without > optimisations, but ghci chokes on it with an internal error. So my > question is if I can expect this to work at least this much in the long > run, or is it a hopelessly fragile hack? > > Gergely > > -- > http://www.fastmail.fm - Same, same, but different... > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe >
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