Hi,
Please can someone explain why these two expression behave differently -
----
fmap (\x -> x) Just 2
Just 2
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fmap (\x -> x+2) Just 2
No instance for (Num (Maybe a0)) arising from a use of `it'
In a stmt of an interactive GHCi command: print it
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The first expression evaluates fine whereas the second one fails. However if I do -
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fmap (\x -> x+2) $ Just 2
Just 4
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Then the second expression also returns the Maybe value. Why is $ needed in second expression but not in the first one ?
Thanks,