[Haskell-cafe] Question on a common pattern

[tsuraan]

In my code, I'm doing this quite a lot:

x <- someIO
case x of
  Opt1 -> ...

Having a line for extracting the value from the IO (or STM) and then
acting on the value seems unnatural.  Is there a more concise way to
do this?  This code:

case someIO of
  Opt1 -> ...

Doesn't work, but is there something like that, that is valid?