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Unsafe functions

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* <hask>unsafeIOToSTM :: IO a -> STM a</hask>
 
* <hask>unsafeIOToSTM :: IO a -> STM a</hask>
 
* <hask>unsafeFreeze, unsafeThaw</hask>
 
* <hask>unsafeFreeze, unsafeThaw</hask>
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* <hask>unsafeCoerce# :: a -> b</hask>
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* <hask>seq :: a -> b -> b</hask>
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Unsafe functions can break type safety (unsafeCoerce#, unsafePerformIO),
 +
interfere with lazy IO (unsafeInterleaveIO), or break paramatericity (seq).
 +
There use (except in the case of <hask>seq</hask>) would require some
 +
kind of assurance on the part of the programmer that what they're doing
 +
is safe.
  
 
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[[Category:Idioms]]

Revision as of 01:20, 8 October 2006

There are a number of unsafe functions in the libraries.

  • unsafePerformIO :: IO a -> a
  • unsafeInterleaveIO :: IO a -> IO a
  • unsafeInterleaveST :: ST s a -> ST s a
  • unsafeIOToST :: IO a -> ST s a
  • unsafeIOToSTM :: IO a -> STM a
  • unsafeFreeze, unsafeThaw
  • unsafeCoerce# :: a -> b
  • seq :: a -> b -> b

Unsafe functions can break type safety (unsafeCoerce#, unsafePerformIO), interfere with lazy IO (unsafeInterleaveIO), or break paramatericity (seq).

There use (except in the case of
seq
) would require some

kind of assurance on the part of the programmer that what they're doing is safe.

This article is a stub. You can help by expanding it.