My favorite is accursedUnutterablePerformIO https://hackage.haskell.org/package/bytestring-0.12.1.0/docs/Data-ByteString-Internal.html#g:10 https://hackage.hask

My favorite is accursedUnutterablePerformIO https://hackage.haskell.org/package/bytestring-0.12.1.0/docs/Data-ByteString-Internal.html#g:10 https://hackage.haskell.org/package/bytestring-0.12.1.0/docs... This "function" has a superficial similarity to unsafePerformIO but it is in fact a malevolent agent of chaos. It unpicks the seams of reality (and the IO monad) so that the normal rules no longer apply. It lulls you into thinking it is reasonable, but when you are not looking it stabs you in the back and aliases all of your mutable buffers. The carcass of many a seasoned Haskell programmer lie strewn at its feet.