Difference between revisions of "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),
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interfere with lazy IO (unsafeInterleaveIO), or break paramatericity (seq).
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There use (except in the case of <hask>seq</hask>) would require some
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kind of assurance on the part of the programmer that what they're doing
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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.

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