[Haskell-cafe] Problem about exception.

[Magicloud Magiclouds]

On Thu, Jan 27, 2011 at 11:09 AM, Brandon S Allbery KF8NH
<allbery.b at gmail.com> wrote:
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> On 1/26/11 22:02 , Magicloud Magiclouds wrote:
>> Sorry, in last mail, I meant, in really wrong situation, there might
>> be other tens of unexpected command, I'd like to wrap them in one
>> exception, other than making tens of exceptions.
>
> I'm not sure you can get away with that in a monadic computation, unless you
> hold all the exceptions until everything is done... and if there's no way to
> control "everything is done" you have a potential DoS.  (Worse, it looked to
> me like one of those ControlExceptiion-s *was* the "everything is done",
> which makes holding onto things problematic plus makes me wonder what good
> the debug message is if it's batched until protocol shutdown.
>
> - --
> brandon s. allbery     [linux,solaris,freebsd,perl]      allbery at kf8nh.com
> system administrator  [openafs,heimdal,too many hats]  allbery at ece.cmu.edu
> electrical and computer engineering, carnegie mellon university      KF8NH
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Yes, the problem is that Exception cannot hold anything in it. Things
like Either might work. I am thinking how to make it work with
StateT....

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