Re: Proposal: Add throwSTM and generalize catchSTM

On Sun, 2010-09-26 at 15:46 -0400, Simon Marlow wrote:

On 26/09/10 13:55, Bas van Dijk wrote:

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On Sun, Sep 26, 2010 at 6:13 PM, Antoine Latter wrote:

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Your new catchSTM can be written from the old one:

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newCatchSTM stm h = catchSTM stm (h . fromJust . fromException . toException)

Agree in principle, but I don't think that implementation works, does it? If the exception is the wrong type, fromJust will throw an error, whereas you want to just re-throw the original exception.

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I will make a patch out of this and attach it to the ticket. We'll see what the GHC devs think of it.

Fine by me.

Cheers, Simon

newCatchSTM stm h = catchSTM stm (\e -> maybe (throwSTM e) f $ fromException e) Regards