Catching all exceptions from within an enclosed computation https://github.com/jcristovao/enclosed-exceptions

Version on this page:
LTS Haskell 12.6:1.0.3
Stackage Nightly 2018-08-15:1.0.3
Latest on Hackage:1.0.3

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MIT licensed by Michael Snoyman, João Cristóvão
Maintained by jmacristovao@gmail.com, michael@snoyman.com

Module documentation for


The purpose of this module is to allow you to capture all exceptions originating from within the enclosed computation, while still reacting to asynchronous exceptions aimed at the calling thread.

This way, you can be sure that the function that calls, for example, catchAny, will still respond to ThreadKilled or Timeout events raised by another thread (with throwTo), while capturing all exceptions, synchronous or asynchronous, resulting from the execution of the enclosed computation.

One particular use case is to allow the safe execution of code from various libraries (which you do not control), capturing any faults that might occur, while remaining responsive to higher level events and control actions.

This library was originally developed by Michael Snoyman for the ClassyPrelude library, and was latter spun-off into a separate independent package.

For a more detailed explanation of the motivation behind this functions, see:

Catching all exceptions


the discussion in haskell-cafe


ChangeLog for enclosed-exceptions


  • Skip some tests on GHC 8.4 #12

  • Support for GHC 7.4 and earlier


  • Use MVar in tryAny, drop async dependency #9


  • Added tryDeep and catchDeep
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