dmhouse:
> On 16/11/06, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
> >And if we are absolutely positive that the value is (Just x),
> >we can always write
> > maybe (assert False undefined) id v
>
> It should be pointed out that Data.Maybe does export a less well-known
> function, fromMaybe:
>
> fromMaybe z = maybe z id
>
> This can be used to make the 'maybe X id' case a bit tidier (although
> technically it's not a save on characters).
How controversial would a proposal to {-# DEPRECATE fromJust #-} be, in
favour of:
Just _ = x -- which will give you the precise line number
maybe (assert False)
maybe id
fromMaybe
It seems to me this is one cause of mysterious newbie errors we
could easily discourage, with little harm.
-- Don
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