Readline read_history and write_history addition

Judah Jacobson judah.jacobson at
Sat Feb 2 15:03:55 EST 2008

On Sat, Feb 2, 2008 at 11:30 AM, Yitzchak Gale <gale at> wrote:
> Alexander Dunlap wrote:
>  > For instances where an exception would be too intrusive, I don't see
>  > how it would be too hard to write a wrapper function
>  In a library that does not have direct access to the IO
>  monad, it would be not just hard - it would be impossible.
>  That is because of type restrictions in the current versions
>  of catch, block, and friends.

You haven't said why something like the following would not be sufficient:

readHistoryM :: MonadIO m => String -> m Bool
readHistoryM file = liftIO $ do
    result <- try (readHistory file)
    return (result == Right ())


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