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| author | Tom Sydney Kerckhove <syd@cs-syd.eu> | 2021-03-09 09:24:05 +0100 |
|---|---|---|
| committer | Hécate Moonlight <kleidukos@crypto-keupone.eu> | 2021-10-15 06:51:18 +0000 |
| commit | 7a8171bc9db792b19a2ee4dda9e019de5e24ebe0 (patch) | |
| tree | 711cd55fa9ca0dc33160b3074dccda9a73dbbbc0 /libraries/base/GHC/IO | |
| parent | 481e6b546cdbcb646086cd66f22f588c47e66151 (diff) | |
| download | haskell-7a8171bc9db792b19a2ee4dda9e019de5e24ebe0.tar.gz | |
Insert warnings in the documentation of dangerous functions
Diffstat (limited to 'libraries/base/GHC/IO')
| -rw-r--r-- | libraries/base/GHC/IO/Unsafe.hs | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/libraries/base/GHC/IO/Unsafe.hs b/libraries/base/GHC/IO/Unsafe.hs index 5284dcf887..e6c43e920c 100644 --- a/libraries/base/GHC/IO/Unsafe.hs +++ b/libraries/base/GHC/IO/Unsafe.hs @@ -117,6 +117,10 @@ monadic use of references. There is no easy way to make it impossible once you use 'unsafePerformIO'. Indeed, it is possible to write @coerce :: a -> b@ with the help of 'unsafePerformIO'. So be careful! + +WARNING: If you're looking for "a way to get a 'String' from an 'IO String'", +then 'unsafePerformIO' is not the way to go. Learn about do-notation and the +@<-@ syntax element before you proceed. -} unsafePerformIO :: IO a -> a unsafePerformIO m = unsafeDupablePerformIO (noDuplicate >> m) |