[Haskell-beginners] the ($) function (was desugaring an example from RWH)

[John Hartnup]

I had exactly the same confusion - not explaining ($) in RWH was major
dropped ball IMO.

>
> bogusTransfer qty fromBal toBal = do
>     fromQty <- atomically $ readTVar fromBal
>     [snip]
>

... is equivalent to:
bogusTransfer qty fromBal toBal = do
     fromQty <- atomically ( readTVar fromBal
     [snip]
     )

... so using ($) prevents accumulating a great big set of parentheses
to close at the end of a long block.


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"There is no way to peace; peace is the way"