[Haskell-cafe] Problem about exception.

[Brandon S Allbery KF8NH]

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On 1/26/11 22:00 , Magicloud Magiclouds wrote:
> This is one way. But so the outer function could not know what
> happened in "really wrong" situation.

How so?

(1) fromException lets you test it:  if (fromException e :: Maybe
ControlException) returns a (Just ce), then you have a ControlException.

(2) see under (catches) for examples of how to catch specific exception
types.  If you don't catch anything but ControlException then the exception
propagates upward unchanged, which is exactly what you want.

- -- 
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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