Your first line is entirely natural.

The alternative doesn’t look right at all.

I am not aware of a more concise alternative to this general construction (assuming there are multiple case alternative, and that the work can’t be done with library functions).

Chris

From: haskell-cafe-bounces@haskell.org [mailto:haskell-cafe-bounces@haskell.org] On Behalf Of tsuraan
Sent: 14 March 2011 15:49
To: haskell-cafe@haskell.org
Subject: [Haskell-cafe] Question on a common pattern

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?

_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe

---

No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.0.1204 / Virus Database: 1498/3506 - Release Date: 03/14/11